Plant Guide to Vernal Pool Trail, Santa Rosa Plateau

Plant Guide to Vernal Pool Trail, Santa Rosa Plateau

Introduction and Explanation of Plant Trail Guides
Introduction
Highlights of This Trail
Fieldwork Dates and Summary of List Changes With Time
Botanical Trip Reports
The Plant Guide
Comments On Specific Species
Introduction

The Vernal Pool Trail has not just one, but two very unusual botanical features. First, it dramatically shows what California was like ten million years ago, and thus tells part of the story about the evolution of the California flora. Second, it is the only trail in our database that contains a vernal pool, with its unique fauna and flora that can be seen nowhere else in Southern California so readily.
California 10 Million Years Ago And Today

Ten million years ago, California was flat. There were no large mountains, no Sierra Nevada. The mountains that had previously existed (the ancestors of our current Sierra Nevada, for example) had been eroded away as the action from the Pacific plate sliding under North America had moved on to the Rocky Mountain area, and then ceased.
Sometime around 7-15 million years ago, an oceanic-floor spreading center was overridden by the Pacific plate, and the San Andreas Fault first became active. The dying spreading center pushed up the area that is now the San Onofre and Santa Margarita Mountains, and about nine million years ago erupted lava onto the surface of the Earth in the Santa Rosa Plateau area, which flowed over that ~flat surface. Estimates are that the lava covered an area 20 miles across, roughly centered on the Mesa de Colorado.
Because lava is highly resistant to erosion, portions of that lava are still here today as the land eroded away around it. That flat surface now is broken into mesas, including the Mesa de Colorado, which retain the flat surface of ten million years ago. Every other mountainous area of Southern California consists of rugged terrain, with average slopes of around 60°. But the Santa Rosa Plateau consists of flat-topped mesas, and gentle rolling hills where the lava has only recently been eroded. About half of the Vernal Pool Trail is on that lava. See Santa Rosa Plateau Geology for more information.
What biological story does this geologic history tell?
When California was flat, it received summer rain. As a result, the flora of California ten million years ago was not much different from that in the rest of the United States.
About five million years ago, the Sierra Nevada was uplifted, and the climate changed. The high mountains eventually caused the Jet Stream in summer to retreat to our north, and we lost our summer rain. As a result, we lost all our species that require summer rain, except those along watercourses where water was available in the summer.
Those riparian species - willows, sycamores, sedges, etc. - are ones that many Easterners can recognize as being familiar, and are remnants of the California flora from ten million years ago. They are very different from the rest of the California flora today. Those riparian plants still act as if they get summer rain. They lose their leaves in the winter, just when the rest of today's California flora is beginning to grow. Then they grow actively during the summer, when the plants of today's California flora are shutting down to get through the dry season.
Where did the non-riparian plants of today's California flora come from? They came mostly from Mexico, where they evolved in areas without summer rain.
When you walk on the Vernal Pool Trail, think of all the things that have happened since the lava was laid down! When you see riparian plants later, perhaps along the Adobe Loop Trail here, think of the ancestors of these species here ten million years ago, being more widespread and then retreating to the wet places. Think of all the flora now found in Kansas and New Jersey and even China that once was here, but which could no longer survive when the climate changed. When you see our grassland, oak woodland or chaparral plants, think of them migrating thousands of miles from Mexico to colonize land that was now suitable for them.
Such a story told by the rocks you walk on along the flat Vernal Pool Trail!
Vernal Pool Flora

Vernal Pools used to be common in Southern California, and their species were not rare. But humans have destroyed 90-95% of all vernal pools in Southern California, because we like to build our homes in the flat areas where they are found.
A general rule of biology is that the number of species is proportional to area to roughly the 1/3 power. What this means is that if you destroy 90% of an area, you lose half the species. They don't go somewhere else to live; they could survive only in the area where they were found.
As a result, we have already lost half the vernal pool species in Southern California. They are gone. Many of those species we never even knew existed since the pools were destroyed before they were surveyed.
The remaining plants have become endangered. They've become endangered not because they are rare delicate species, or on their way out in evolution; they've become endangered because we humans have killed them relentlessly.
Perversely, because we humans treasure rare things more than common things, we now value these vernal pool plants very highly (which is a good thing!). This trail allows a fantastic look at these plants because it contains a boardwalk over the largest pool at the Santa Rosa Plateau.
There are still many vernal pools left in Southern California, but most of them are on military or private land, and are not easily accessible. Furthermore, this is the only example of a basalt-based vernal pool. All the other pools in Southern California are underlain by hardpan, and the vast majority of them are much smaller than our Main Pool.
Highlights of This Trail

The botanical highlights of this trail are:

Number of Unique Taxa On This Trail

The following histogram gives the number of trails in my database that contain each taxon on this trail. I had 90 trails in our database when this histogram was made; 16 of those trails, including this one, are at the Santa Rosa Plateau Ecological Reserve. A number of "1" means the taxon has only been found only on this list, among all the trails in my database; numbers of "16" or smaller may indicate taxa found only in this area.

Number of Trails
Containing A Taxon Number Of Taxa
On This Trail % of Taxa
On This Trail
1 10 5%
2 11 6%
3 7 4%
4 3 2%
5 4 2%

1-5 35 19%
6-10 22 12%
11-15 21 11%
16-20 34 18%
21-25 19 10%
26-30 14 8%
31-35 7 4%
36-40 11 6%
41-45 14 8%
46-50 3 2%
51-55 6 3%
Total Taxa 186 100%

All taxa found on the trail are included in the above table, although the identity of one taxon still remains to be fully verified.
The taxa found only on this trail, or on only a few trails, or only mostly on trails at the Santa Rosa Plateau, are:

#all Common Name Latin Name
1 yellow carpet Blennosperma nanum var. nanum
1 hooked popcorn flower Plagiobothrys undulatus
1 prostrate navarretia Navarretia prostrata
1 annual hairgrass Deschampsia danthonioides
1 spotted downingia Downingia bella
1 smooth goldfields Lasthenia glaberrima
1 alkali mallow Malvella leprosa
1 Orcutt's quillwort Isoetes orcuttii
1 small-flower western flax Hesperolinon micranthum
1 white-leaf monardella Monardella hypoleuca ssp. hypoleuca
2 woolly marbles Psilocarphus brevissimus var. brevissimus
2 thread-leaved brodiaea Brodiaea filifolia
2 San Diego button-celery Eryngium aristulatum var. parishii
2 willow weed Polygonum lapathifolium
2 water crowfoot Ranunculus aquatilis var. capillaceus
2 *Carolina canarygrass Phalaris caroliniana
2 western toad rush Juncus bufonius var. occidentalis
2 white fairy lantern Calochortus albus
2 *English rye-grass Lolium perenne
2 southern foothill penstemon Penstemon heterophyllus var. australis
3 tawny popcorn flower Plagiobothrys fulvus
3 common lomatium Lomatium utriculatum
3 brown microseris Stebbinsoseris heterocarpa
3 Bolander's water-starwort Callitriche heterophylla var. bolanderi
3 purslane speedwell Veronica peregrina ssp. xalapensis
3 clover fern Marsilea vestita ssp. vestita
3 red-skinned onion Allium haematochiton
4 *brome fescue Vulpia bromoides
4 warty spurge Euphorbia spathulata
4 *brass-buttons Cotula coronopifolia
5 *Mediterranean barley Hordeum marinum ssp. gussoneanum
5 spike primrose Epilobium densiflorum
5 chocolate lily Fritillaria biflora var. biflora
5 gray sage Salvia apiana X S. mellifera
6 shining peppergrass Lepidium nitidum var. nitidum
6 western buttercup Ranunculus occidentalis

Fieldwork Dates and Summary of List Changes With Time

The following table gives the dates the trail was walked and taxa recorded. After each visit, the table gives the total number of taxa on the list and the breakdown of the taxa without positive identification. See Explanation of Plant Trail Guides to understand the symbols below.

Visit Date Visit # # taxa # "?" # "sp" # "~" # "ssp"
12/15/2001 1 70 9 1
2/4/2002 2 87 8 1
2/21/2002 3 120 8 1
3/4/2002 4 132 14 1
3/13/2002 5 129 7 1
3/20/2002 6 130 2 1
4/3/2002 7
4/10/2002 8 134 4 1
4/17/2002 9 136 4 1
4/28/2002 10 139 3 1
5/5/2002 11 139 3 1
5/10/2002 12 139 0 1 1
12/14/2002 13 143 1 0 1 0
1/4/2003 14
1/17/2003 15
1/26/2003 16
2/14/2003 17 149 0 0 4 2
2/28/2003 18 151 0 1 3 2
3/6/2003 19 152 0 1 3 1
3/12/2003 20 152 0 1 2 1
3/19/2003 21 155 0 0 2 1
3/24/2003 22 155 0 0 2 1
3/29/2003 23
4/30/2003 24
5/15/2003 25
6/8/2003 26 172 1 2 1 0
3/30/2004 27 171 0 2 1 0
3/10/2005 28
3/16/2005 29
4/7/2005 30 176 0 0 0 1
4/13/2005 31 177 0 0 0 0
5/26/2005 32 177 0 0 0 0
6/19/2005 33 178 0 0 0 0
8/18/2005 34 179 0 0 1 0
10/15/2005 35 178 0 1 0 0
10/15/2005 35 186 0 1 1 0

I didn't keep track of the changes separately for 3/10/05 and 3/16/05. Prior to 3/10/05, the last portion of the trail was different, which affected only a single species. The 4/7/05 numbers reflect the new alignment of the trail, and also include a new taxon found on Ranch Road near the end of the trail that appeared for the first time in 2005. On 10/15/05, I added the section along Ranch Road, resulting in the addition of 8 taxa. Hence there are two entries in the table above for 10/15/05; the first one is for the previously-defined route.
In addition to the trips above, which concentrated on the plant guide, I made literally dozens of trips in 2001 and recorded the plants that were blooming. Those observations were used to augment the 2002-observed plant list on 2/21/02. Some of those species were never observed on this trail in 2002 due to the severe drought then.
I began using the "~" symbol in June 2002 and the "sp" symbol in August 2002; those categories were given the "?" symbol prior to those dates (we updated the 5/10/02 numbers to reflect our current usage.) I didn't record the numbers after some of the updates, especially the minor later ones.
Two new offtrail species were added from 9/12/05 fieldwork, and another new offtrail species was added from 9/23/05 fieldwork, but the rest of the trail wasn't botanized.
Botanical Trip Reports

List of Plants in Bloom 24 March 2003
30 March 2004
See also many previous botanical trip reports present in Observations of Flowering Plants and the Vernal Pools: Detailed Observations From Each Hike, organized by year, linked from the main page.
The Plant Guide

Version for printing, without lines and other text on this page: html (8 pages), pdf Clickbook booklet (2 double-sided pages), or Large Type pdf Clickbook booklet (4 double-sided pages). (See printing instructions for an explanation of these options)
The mileages have been fit to a detailed GPS recording of the trail up to mile 1.05. Those mileages should be accurate to 0.01-0.02 miles.

Mile S # id? Common Name Latin Name #here #all
0.00 Trailhead on Via Volcano
0.00 b (puncture-vine, Tribulus terrestris)
0.00 r sp (tumble pigweed, Amaranthus albus; annual goosefoot, Chenopodium sp.; telegraph weed, Heterotheca grandiflora; horseweed, Conyza canadensis; Rhodes grass, Chloris gayana)
0.00 r 1 *foxtail barley Hordeum murinum ssp. glaucum⁺ 40 / 2 13
0.00 r 2 *ripgut brome Bromus diandrus 99 / 9 51
0.00 r 3 *shortpod mustard Hirschfeldia incana 99 / 9 51
0.00 c 4 *knotweed Polygonum arenastrum 20 / 5 18
0.00 r 5 *Crete weed Hedypnois cretica 5 / 2 19
0.00 r 6 *short-fruited filaree Erodium brachycarpum 99 / 9 14
0.00 r 7 *wild oats Avena fatua 99 / 9 26
0.00 l 8 *sow thistle Sonchus oleraceus 20 / 5 41
0.00 r 9 blue dicks Dichelostemma capitatum ssp. capitatum 99 / 9 46
0.00 r 10 checkerbloom Sidalcea malviflora ssp. sparsifolia 99 / 9 25
0.00 l 11 *soft chess Bromus hordeaceus 99 / 9 40
0.00 12 *tocalote Centaurea melitensis 99 / 5 45
0.00 r 13 graceful tarplant Holocarpha virgata ssp. elongata 99 / 9 14
0.00 r 14 rusty-haired popcorn flower Plagiobothrys nothofulvus 99 / 9 12
0.00 15 splendid mariposa lily Calochortus splendens 99 / 9 19
0.00 r 16 California plantain Plantago erecta 1 / 1 13
0.00 r 17 soap plant Chlorogalum pomeridianum var. pomeridianum 20 / 5 18
0.00 b 18 *red brome Bromus madritensis ssp. rubens 99 / 9 52
0.00 r 19 *pineapple weed Chamomilla suaveolens 10 / 3 19
0.00 r 20 *smooth cat's ear Hypochaeris glabra 99 / 9 35
0.00 21 dove weed Eremocarpus setigerus 30 / 5 24
0.00 r 22 shining peppergrass Lepidium nitidum var. nitidum 99 / 3 6
0.00 l 23 dwarf lupine Lupinus bicolor 99 / 9 29
0.00 l 24 *Italian rye-grass Lolium multiflorum 99 / 9 17
0.00 r 25 purple clarkia Clarkia purpurea ssp. quadrivulnera 99 / 9 25
0.00 l 26 *California burclover Medicago polymorpha 50 / 4 40
0.00 b 27 balloon clover Trifolium depauperatum var. truncatum 99 / 9 7
0.01 l Sign: "Reserve Fees $2 adults, $1 children"
0.01 r 28 Spanish clover Lotus purshianus var. purshianus 30 / 4 31
0.01 r 29 earth brodiaea Brodiaea terrestris ssp. kernensis 99 / 9 7
0.01 l 30 muilla Muilla maritima 99 / 9 7
0.01 r 31 purple sanicle Sanicula bipinnatifida 99 / 9 11
0.01 r 32 tawny popcorn flower Plagiobothrys fulvus⁺ 99 / 9 3
0.01 r 33 ground pink Linanthus dianthiflorus 99 / 9 9
0.01 l 34 goldfields Lasthenia californica 99 / 9 12
0.01 r 35 common lomatium Lomatium utriculatum 50 / 5 3
0.01 r 36 red maids Calandrinia ciliata 20 / 3 18
0.01 l Display Board
0.01 37 *nit grass Gastridium ventricosum 99 / 9 24
0.01 b 38 *hairy rattail fescue Vulpia myuros var. hirsuta 99 / 9 18
0.01 r 39 *slender wild oats Avena barbata 50 / 3 39
0.01 r 40 purple needlegrass Nassella pulchra 99 / 9 19
0.01 r 41 *prickly lettuce Lactuca serriola 99 / 9 42
0.01 l 42 yellow carpet Blennosperma nanum var. nanum 99 / 9 1
0.01 l Sign: "Vernal Pool Trail (ahead); To Large Pool 0.7 mi; To Adobes 1.7 mi"
0.01 l 43 pygmy-weed Crassula connata 50 / 2 28
0.01 l 44 silver puffs Uropappus lindleyi 99 / 9 26
0.01 r 45 *mouse-ear chickweed Cerastium glomeratum 5 / 2 19
0.01 r 46 owl's-clover Castilleja densiflora⁺ 99 / 5 7
0.01 r 47 *windmill pink Silene gallica 20 / 2 33
0.01 r 48 *narrowleaf filago Filago gallica 20 / 2 45
0.01 r 49 brown microseris Stebbinsoseris heterocarpa 50 / 3 3
0.01 l (San Diego wreathplant, Stephanomeria diegensis)
0.02 b 50 California-aster Lessingia filaginifolia var. filaginifolia 30 / 9 51
0.03 r 51 *redstem filaree Erodium cicutarium 20 / 2 55
0.04 l (coast live oak, Quercus agrifolia var. agrifolia)
0.04 r 52 vinegar weed Trichostema lanceolatum 20 / 5 14
0.05 l 53 one-sided bluegrass Poa secunda ssp. secunda 10 / 3 23
0.05 54 *goldentop Lamarckia aurea 99 / 3 21
0.05 r 55 sharp-toothed sanicle Sanicula arguta 20 / 6 16
0.06 l 56 San Diego birdsfoot lotus Lotus hamatus 5 / 1 24
0.06 l 57 bajada lupine Lupinus concinnus 30 / 3 11
0.06 l 58 long-stemmed buckwheat Eriogonum elongatum var. elongatum 20 / 3 27
0.06 l 59 angel's gilia Gilia angelensis 40 / 1 14
0.06 l (In prickly-pear: Vasey's prickly-pear, Opuntia vaseyi; *bull thistle, Cirsium vulgare; California fuchsia, Epilobium canum ssp. canum; wild cucumber, Marah macrocarpus var. macrocarpus; and poison oak, Toxicodendron diversilobum.
60 *sand spurrey Spergularia bocconei⁺ 10 / 2 13
0.09 r 61 fringe-pod Thysanocarpus curvipes 10 / 2 9
l 62 rattlesnake weed Daucus pusillus 10 / 2 28
r 63 *scarlet pimpernel Anagallis arvensis 10 / 2 32
0.10 l 64 San Diego morning-glory Calystegia macrostegia ssp. tenuifolia⁺ 10 / 3 18
l 65 *hedge mustard Sisymbrium officinale 30 / 2 20
r 66 *white sweetclover Melilotus albus 10 / 1 7
0.11 l (large Engelmann oak, Quercus engelmannii)
0.11 r 67 *brome fescue Vulpia bromoides / 4
0.11 r 68 blue larkspur Delphinium parryi ssp. parryi 20 / 3 13
0.12 r 69 blue-eyed grass Sisyrinchium bellum 99 / 9 19
0.12 b 70 johnny jump-up Viola pedunculata 99 / 9 16
0.12 l Jct. Los Santos Trail. Enter mustard and wild oats "desert", crowding out natives, mostly on right.
0.12 l (California buckwheat, Eriogonum fasciculatum var. foliolosum)
0.13 l (telegraph weed, Heterotheca grandiflora)
0.14 l 71 *curly dock Rumex crispus 99 / 5 23
0.14 r (California everlasting in prickly pear)
0.15 l 72 Vasey's prickly-pear Opuntia vaseyi⁺ 10 / 2 24
0.15 l (coast live oak, Quercus agrifolia var. agrifolia)
0.16 r 73 San Diego wreathplant Stephanomeria diegensis 20 / 4 21
r 74 pin-point clover Trifolium gracilentum var. gracilentum 10 / 2 8
r 75 small-head field clover Trifolium microcephalum 10 / 1 10
76 shooting star Dodecatheon clevelandii ssp. clevelandii 99 / 3 11
l Check specimens here for bloom to see if they are common spikerush, , or wire rush, Juncus balticus
0.20 l 77 *prickly sow thistle Sonchus asper ssp. asper / 1 30
0.20 l Badger holes appeared here July 2002; nearly filled in by gophers in December 2002
0.20 r 78 *Mediterranean barley Hordeum marinum ssp. gussoneanum 50 / 2 5
0.20 r 79 warty spurge Euphorbia spathulata 99 / 9 4
0.21 r Jct. short path to old percolation pit, now a mini-vernal pool, and ok to visit. Next 7 taxa at perc pit
0.21 80 hooked popcorn flower Plagiobothrys undulatus 99 / 2 1
0.21 81 Bolander's water-starwort Callitriche heterophylla var. bolanderi 99 / 2 3
0.21 82 woolly marbles Psilocarphus brevissimus var. brevissimus 50 / 2 2
0.21 83 spike primrose Epilobium densiflorum 10 / 1 5
0.21 84 prostrate navarretia Navarretia prostrata 5 / 1 1
0.21 85 common spikerush Eleocharis macrostachya 99 / 3 11
0.21 86 thread-leaved brodiaea Brodiaea filifolia 50 / 4 2
0.22 Back on main trail
0.25 l (large Engelmann oak, Quercus engelmannii)
0.26 l Outer part of curve of trail is one of the best shooting star fields, accompanied by blennosperma and goldfields.
0.29 l 87 Two young Engelmann oaks Quercus engelmannii 10 / 5 23
r (Check for Plagiobothrys arizonicus or intergrade with it)
0.34 r 88 western buttercup Ranunculus occidentalis⁺ 50 / 9 6
0.34 Curve left
0.35 b 89 California poppy Eschscholzia californica 30 / 3 29
90 *long-beaked filaree Erodium botrys 50 / 5 11
r Pristine field of purple needlegrass, Nassella pulchra
0.40 l Famous "see-through" tree shell in distance on left, with just bark left standing.
0.40 r 91 *(gazania) Gazania X (mounding hybrid)⁺ 1 / 1 6
0.42 l 92 nodding needlegrass Nassella cernua 99 / 5 16
0.42 l Jct. Trans Preserve Trail
0.43 l (coyote bush, Baccharis pilularis)
0.44 r 93 white everlasting Gnaphalium canescens ssp. microcephalum 7 / 3 36
0.45 l 94 Mexican rush Juncus mexicanus 20 / 1 16
0.46 r 95 *winter vetch Vicia villosa ssp. varia⁺ 99 / 1 19
0.47 l Display Board with story of Vernal Pool on one side, basalt weathering on the other.
0.48 l (laurel sumac, Malosma laurina))
0.49 l First large Engelmann oak, Quercus engelmannii, on the trail
0.49 l 96 laurel sumac Malosma laurina 10 / 3 42
0.50 l 97 California everlasting Gnaphalium californicum⁺ 30 / 4 42
0.55 Trail bends left
98 *tumble pigweed Amaranthus albus 3 / 2 12
0.61 r 99 *(bull thistle) Cirsium vulgare⁺ 1 / 1 17
0.63 l Begin main population of thread-leaved brodiaea, Brodiaea filifolia
0.64 Bench; Jct. loop trail around pool. Go right to pool, taking the loop counter-clockwise.
0.65 b 100 slender tarweed Hemizonia fasciculata 20 / 2 17
0.66 Begin boardwalk. The hooked popcorn flower makes the white color at the Pool.
0.66 r 101 purslane speedwell Veronica peregrina ssp. xalapensis 10 / 2 3
0.66 r 102 common bedstraw Galium aparine⁺ 20 / 2 38
0.66 l 103 *rabbits-foot grass Polypogon monspeliensis 20 / 2 22
0.66 r 104 annual hairgrass Deschampsia danthonioides 20 / 1 1
0.66 l 105 San Diego button-celery Eryngium aristulatum var. parishii 50 / 1 2
0.66 r 106 *brass-buttons Cotula coronopifolia 10 / 2 4
0.66 b 107 spotted downingia Downingia bella 99 / 1 1
0.67 r 108 smooth goldfields Lasthenia glaberrima 5 / 1 1
0.67 r 109 willow weed Polygonum lapathifolium⁺ 1 / 1 2
0.67 b 110 alkali mallow Malvella leprosa 40 / 2 1
0.68 l 111 knot grass Paspalum distichum 99 / 2 7
0.68 r 112 Orcutt's quillwort Isoetes orcuttii 1 / 1 1
0.68 Center of boardwalk
0.68 r 113 water crowfoot Ranunculus aquatilis var. capillaceus 5 / 1 2
0.68 c 114 *grass poly Lythrum hyssopifolia 10 / 1 14
0.68 r 115 clover fern Marsilea vestita ssp. vestita 10 / 1 3
0.69 r 116 *Carolina canarygrass Phalaris caroliniana 1 / 1 2
0.71 b 117 *cut-leaved geranium Geranium dissectum 20 / 1 13
0.71 End boardwalk; continue on loop trail
0.71 l Blennosperma and goldfields patch
0.73 r 118 western toad rush Juncus bufonius var. occidentalis 10 / 1 2
0.74 (Check for different Plagiobothrys, collinus?)
0.79 Spot from which pool pictures were taken for 2002 onward.
0.83 End loop trail; continue on Vernal Pool Trail to the right.
0.85 Spot from which pool pictures were taken for 2001.
0.85 r (In the prickly pear: coast-range melic, Melica imperfecta; bee plant, Scrophularia californica ssp. floribunda; and bicolored everlasting, Gnaphalium bicolor.)
0.88 r Badger holes appeared here April 2002, the first badger holes on the trail in my experience (since 1996). Nearly filled in by gophers in December 2002
0.89 r 119 *spring vetch Vicia sativa ssp. sativa 30 / 3 6
0.91 l Second set of April 2002 badger holes
0.91 End wheelchair-accessible portion of trail
0.91 l 120 coast live oak Quercus agrifolia var. agrifolia 1 / 1 42
0.91 l Engelmann oak growing inside the coast live oak
0.92 l 121 coast-range melic Melica imperfecta 10 / 2 43
0.92 l (Flat-topped bent Englemann oak off trail. It probably grew under another tree that is no longer present.)
l (hollyleaf redberry, Rhamnus ilicifolia, in prickly pear)
0.93 l View of Elsinore peak with ~6 antenna on it at ~10 o'clock
l (white sage, Salvia apiana)
0.94 l 122 bush lupine Lupinus excubitus var. hallii 5 / 1 10
0.94 l 123 lanceleaf dudleya Dudleya lanceolata 1 / 1 20
0.95 l 124 bird's-foot fern Pellaea mucronata var. mucronata 1 / 1 30
1.00 b Field of shooting stars
1.01 r White variant of owl's-clover, Castilleja densiflora
1.04 r 125 tomcat clover Trifolium willdenovii 20 / 1 17
1.04 r California everlasting Gnaphalium californicum⁺ /
1.05 Trail turns right and drops off top of Mesa de Colorado
1.05 l 126 *white-stemmed filaree Erodium moschatum 20 / 1 20
1.05 l 127 coffee fern Pellaea andromedifolia 1 / 1 22
1.05 l 128 caterpillar phacelia Phacelia cicutaria var. hispida 50 / 1 16
1.05 b 129 wild-cucumber Marah macrocarpus var. macrocarpus 5 / 1 44
1.05 l 130 leafy daisy Erigeron foliosus var. foliosus 1 / 1 43
1.06 l 131 poison oak Toxicodendron diversilobum 5 / 1 43
1.06 r 132 California fuchsia Epilobium canum ssp. canum 1 / 1 20
1.06 r common bedstraw Galium aparine⁺ /
1.06 l (Nice stand of somewhat hidden blue dicks, Dichelostemma capitatum ssp. capitatum, San Diego pea, Lathyrus vestitus var. alefeldii, and south coast morning-glory, Calystegia macrostegia ssp. intermedia.)
1.06 r (white everlasting, Gnaphalium canescens ssp. microcephalum)
1.07 l 133 bicolored everlasting Gnaphalium bicolor 5 / 2 29
1.07 r 134 slender vetch Vicia hassei 10 / 3 6
1.07 r 135 pellitory Parietaria hespera var. hespera 1 / 1 6
1.07 l 136 white-flowering currant Ribes indecorum 10 / 3 22
1.07 r 137 southern miner's lettuce Claytonia perfoliata ssp. mexicana 20 / 2 25
1.07 r 138 *hedge parsley Torilis nodosa 20 / 1 14
1.07 r 139 San Diego pea Lathyrus vestitus var. alefeldii 2 / 2 21
1.07 r 140 south coast morning-glory Calystegia macrostegia ssp. intermedia⁺ 10 / 1 19
1.07 r 141 blue wildrye Elymus glaucus ssp. glaucus 20 / 1 21
1.08 142 *(milk thistle) Silybum marianum⁺ 1 / 1 9
1.09 r 143 climbing bedstraw Galium nuttallii ssp. nuttallii 10 / 3 30
1.09 r Bench
1.11 r Field of purple sanicle
1.12 l 144 toyon Heteromeles arbutifolia 10 / 2 44
1.14 l (chocolate lily, Fritillaria biflora var. biflora)
1.15 r (Engelmann oak, Quercus engelmannii, with a few crown galls, lost two major limbs from main trunk in summer 2005)
1.17 Enter Fairy Lane, a short section of chaparral / coastal sage scrub lined with Fairy Lanterns (in season).
1.17 b 145 white fairy lantern Calochortus albus 50 / 2 2
1.17 b 146 Torrey's scrub oak Quercus acutidens 20 / 2 26
1.17 r 147 sticky cinquefoil Potentilla glandulosa ssp. glandulosa 20 / 2 17
1.18 b 148 Pacific sanicle Sanicula crassicaulis 5 / 2 20
1.18 r 149 narrowleaf bedstraw Galium angustifolium ssp. angustifolium 10 / 2 48
1.18 r 150 saw-toothed goldenbush Hazardia squarrosa var. grindelioides 20 / 2 35
1.18 b 151 deerweed Lotus scoparius var. scoparius 20 / 2 29
1.18 r 152 bush monkeyflower Mimulus aurantiacus 10 / 1 42
1.18 l (sacapellote, Acourtia microcephala)
1.20 r 153 black sage Salvia mellifera 30 / 2 40
1.20 r 154 sugar bush Rhus ovata⁺ 5 / 2 25
1.20 l 155 *purple false-brome Brachypodium distachyon 20 / 1 6
1.20 b 156 chamise Adenostoma fasciculatum 20 / 1 37
1.20 r 157 southern honeysuckle Lonicera subspicata var. denudata 5 / 2 40
1.20 r 158 heartleaf penstemon Keckiella cordifolia 2 / 2 27
1.22 r 159 small-flower western flax Hesperolinon micranthum 50 / 3 1
1.23 l 160 chocolate lily Fritillaria biflora var. biflora 50 / 9 5
1.23 161 yellow mariposa lily Calochortus weedii var. weedii 10 / 1 10
1.23 l 162 golden yarrow Eriophyllum confertiflorum var. confertiflorum 20 / 2 55
1.24 b 163 red-skinned onion Allium haematochiton 10 / 3 3
1.24 164 *English rye-grass Lolium perenne 1 / 1 2
1.24 Local low point on trail
1.24 r (chocolate lily, Fritillaria biflora var. biflora in field of red-skinned onion, Allium haematochiton)
1.24 l 165 southern foothill penstemon Penstemon heterophyllus var. australis 1 / 1 2
1.24 r 166 foothill needlegrass Nassella lepida 20 / 1 20
1.27 l 167 Eastwood manzanita Arctostaphylos glandulosa ssp. zacaensis 5 / 2 11
1.28 r 168 white-leaf monardella Monardella hypoleuca ssp. hypoleuca 5 / 1 1
1.30 r 169 hollyleaf redberry Rhamnus ilicifolia 5 / 1 43
1.30 Cross drainage
l (One or two *olive trees, Olea europaea present in 2001 were removed in 2002.)
1.31 Local high point on trail
1.32 Interesting mushrooms, light brown with dark brown edge.
1.33 r 170 white sage Salvia apiana 1 / 1 38
1.33 r 171 gray sage Salvia apiana X S. mellifera⁺ 1 / 1 5
1.34 Local low point on trail
1.35 r 172 narrow-leaved miner's lettuce Claytonia parviflora ssp. parviflora 2 / 1 19
1.35 r (California peony, Paeonia californica)
1.35 Local high point on trail
1.36 l 173 blue elderberry Sambucus mexicana 1 / 1 48
1.36 End chaparral
1.37 b First large patch of chocolate lily, Fritillaria biflora var. biflora
1.37 Trail was rerouted in 2004 to eliminate the mudpit section. The new trail has many more chocolate lilies on it!
1.44 l 174 slender madia Madia gracilis 3 / 1 19
1.45 r 175 *olive Olea europaea 1 / 1 10
1.48 Cross small drainage
1.52 r 176 strigose lotus Lotus strigosus 10 / 1 33
1.53 Trail zigzags left
1.54 r White variant of dwarf lupine, Lupinus bicolor
1.54 b 177 Indian milkweed Asclepias eriocarpa 1 / 1 17
1.57 Jct. Ranch Road. Turn right, toward adobes
1.59 l 178 *rose clover Trifolium hirtum 2 / 1 12
1.59 r 179 western ragweed Ambrosia psilostachya 10 / 1 39
1.61 b 180 horseweed Conyza canadensis 5 / 1 40
1.61 r Jct. old Vernal Pool Trail; plants at Adobes not described here; most have been planted.
1.62 l 181 *little horseweed Conyza bonariensis 5 / 1 18
1.64 l (horehound, Marrubium vulgare)
1.66 l 182 fragrant everlasting Gnaphalium canescens ssp. beneolens 1 / 1 24
1.66 l 183 ~ *Chinese elm Ulmus parvifolia 2 / 1 2
1.67 r 184 *Bermuda grass Cynodon dactylon 10 / 2 33
1.67 r 185 *English plantain Plantago lanceolata 5 / 1 20
1.67 Jct. Adobes; guide doesn't include plants at Adobes, and resumes back at the jct. with the Vernal Pool Trail. There is a porta-potty at Adobes.
1.77 Jct. Vernal Pool Trail; guide continues west along Ranch Road toward Trans-Preserve Trail
1.92 b 186 stinking gourd Cucurbita foetidissima 5 / 1 9
2.06 Road curves right 90°
2.12 Jct. Hidden Valley Road; turn left
2.19 Jct. S. Trans Preserve Trail; end guide

Comments On Specific Species

Hordeum murinum ssp. glaucum. As I have also seen on the Mt. Wilson Toll Road in the San Gabriel Mountains; the Backbone Trail in the Santa Monica Mountains; and plants at my house in Fallbrook in San Diego County, these plants key perfectly to ssp. leporinum in Munz, but are perfect ssp. glaucum in JM. My id is due to my general conformance with the JM.
I suspect that the two subspecies are no longer separate in Southern California, due to hybridization of the formerly separate subspecies. I am accumulating data from many locations in Southern California to analyze this.
Plagiobothrys fulvus. This taxon, found here and in the adjacent San Mateo Wilderness Area, is disjunct from the rest of its species found in Northern California (NcoR, SNF, SnFrB), Oregon and Chile. The North American plants have been called var. campestris.
Castilleja densiflora. The two subspecies are supposedly geographically distinct, with ssp. densiflora found either in Los Angeles County north (Munz) or only in northern California (NcoR, c SNF, ScoR; JM), and ssp. gracilis found mostly in Southern California (ScoR, SW, n Baja CA).
However, the specimens here, and especially those at Daley Ranch, have more ssp. densiflora traits than those of ssp. gracilis! In particular, two out of three specimens in the population near the Main Pool clearly key out as ssp. densiflora, with a calyx of 12-13 mm, a lower corolla lip that widens gradually and pouches that are distinctly longer than deep. However, the ssp. densiflora specimens do not have bracts as long as the corolla and the corolla is exserted.
I have therefore decided to go along with the treatment by both the Western Riverside County Checklist by Roberts et al, and the Flora of the Santa Rosa Plateau by Lathrop and Thorne, where they have discarded the subspecies.
Spergularia bocconei. This weedy non-native species is on the Red List as a critically endangered plant in its native land, the United Kingdom! This is an excellent example of why non-native plants have unfair advantages in competition with native plants, and why "survival of the fittest" is not applicable here.
Calystegia macrostegia ssp. arida. About half the plants at the SRP appear to be ssp. arida, with the other half split between sspp. "intermedia" and "tenuifolia". It has long troubled me to be finding three subspecies in the small area of the SRP. Worse, the classification of a given plant has changed with time, which was extremely puzzling.
These difficulties were resolved when I found clear evidence that subspecies "intermedia" and "tenuifolia" are bogus. Hence I assign all the SRP plants to ssp. arida.
Opuntia vaseyi. The identification for these young plants came from plants with flowers near the Main Vernal Pool. Note that the JM calls this Opuntia Xvaseyi, but to my knowledge there is no strong evidence that this is a hybrid. These plants are certainly not hybrids produced from two separate parents; of course, hybridization may have been involved in the origin of this species. This species is found extensively in the SCo region, typically from a few to 20 miles inland from the coast, where it is the dominant species. Every single prickly pear that I have seen in the Santa Rosa Plateau Ecological Reserve is this species.
Gazania X (mounding hybrid); Cirsium vulgare; Silybum marianum. These weeds are eliminated whenever observed. Thus you will not necessarily see them on the trail. They are listed here because they were observed in those locations at one time, and hence are likely to occur again.
Ranunculus occidentalis. Lathrop and Thorne (1985) identified the species here as Ranunculus californicus, but they are in fact R. occidentalis. In particular, they generally have 5 petals, sometimes 6 petals, infrequently up to 12 petals, and the petals are ~round. These are both key characteristics of R. occidentalis, compared to the 9-17 petals and petal length ~ two times its width of R. californicus. They also have only the glabrous receptacles of R. occidentalis.
I examined the voucher specimens of Lathrop and Thorne at RSA, to see how they arrived at their species determination. One voucher was of a plant with 8 petals per flower! I've seen perhaps 1 in 1,000 plants like that at the SRP, and it is understandable that they keyed that one to R. californicus. A second voucher showed a plant with 5 petals per flower, our typical plant at the SRP. Thorne called that "R. californicus, appearing as R. occidentalis". (;-) Their third and last voucher showed a plant with 5 petals, with simply R. californicus as the id.
Thus the Lathrop and Thorne classification was based on an improbably-bad sampling of the plants at the srp, and is clearly wrong.
I have since found another population that appears to be similar to the SRP population at Palomar State Park. These two populations appear to be the southernmost outposts of R. occidentalis.
I have also found four occurrences of the true R. californicus population in Southern California, at Laurel Canyon in Orange County; East Grade Project Road in the eastern Palomar Mountains; and the Kelly Ditch Trail and Garnet Peak Trail / Penny Pines Trailhead in the Laguna Mountains. Those populations are quite different from these plants, with the expected 8 and more petals that are ~two times longer than wide.
The "problem" with a Ranunculus occidentalis id may be simply that this species is not supposed to occur south of the Tehachapi Mountains. This was the botanical wisdom prior to the discovering of these populations of plants at the SRP and at Palomar Mountain, since those areas had not been surveyed at the time that wisdom was stated. This is not a compelling reason to accept the other id, especially since the SRP contains other taxa that are not "supposed to be" in Southern California, such as Plagiobothrys fulvus.
Vicia villosa ssp. varia. Although a few plants grow immediately next to the trail (for the first time in 2003), the vast majority of the plants here are off-trail to the south, at the north base of the oak tree south of the Display Board. A large number of these annuals combine to provide a burst of purple color there, easily visible from the trail.
Gnaphalium californicum. There is a single small plant at the first location along the trail, which is easily missed. The largest collection of them is at mile 0.94.
Galium aparine. A single specimen was observed at the beginning of the boardwalk in 2002 and 2003; all other specimens are found at mile 0.95.
Polygonum lapathifolium. A single plant germinated in the Main Pool in 2005, but died before reaching maturity. This species cannot survive here, since there is no source of water that remains below ground once the pool dries up.
Rhus ovata. This particular specimen is hard to see. A black sage mostly hides it from view. There are several more prominent specimens in a short distance.
Salvia apiana X S. mellifera. This specimen is immediately next to a S. apiana of the same size, making it very easy to compare the two. Note the greenish leaves of the hybrid, compared to the whitish leaves of Salvia apiana. The leaves of the hybrid also have a different smell when rubbed. The difference is most noticeable in the inflorescence. The hybrid has the long wand of S. apiana, but the wand exhibits the typical interrupted inflorescence of S. mellifera.
I thank Jane Strong for her considerable assistance with helping me to learn the plants of the Santa Rosa Plateau, and Kay Madore, Zach Principe and Michael Charters for their sharp eyes in helping me find interesting things on this trail.

Number of Trails Containing A Taxon	Number Of Taxa On This Trail	% of Taxa On This Trail
1	10	5%
2	11	6%
3	7	4%
4	3	2%
5	4	2%

1-5	35	19%
6-10	22	12%
11-15	21	11%
16-20	34	18%
21-25	19	10%
26-30	14	8%
31-35	7	4%
36-40	11	6%
41-45	14	8%
46-50	3	2%
51-55	6	3%
Total Taxa	186	100%

#all	Common Name	Latin Name
1	yellow carpet	Blennosperma nanum var. nanum
1	hooked popcorn flower	Plagiobothrys undulatus
1	prostrate navarretia	Navarretia prostrata
1	annual hairgrass	Deschampsia danthonioides
1	spotted downingia	Downingia bella
1	smooth goldfields	Lasthenia glaberrima
1	alkali mallow	Malvella leprosa
1	Orcutt's quillwort	Isoetes orcuttii
1	small-flower western flax	Hesperolinon micranthum
1	white-leaf monardella	Monardella hypoleuca ssp. hypoleuca
2	woolly marbles	Psilocarphus brevissimus var. brevissimus
2	thread-leaved brodiaea	Brodiaea filifolia
2	San Diego button-celery	Eryngium aristulatum var. parishii
2	willow weed	Polygonum lapathifolium
2	water crowfoot	Ranunculus aquatilis var. capillaceus
2	*Carolina canarygrass	Phalaris caroliniana
2	western toad rush	Juncus bufonius var. occidentalis
2	white fairy lantern	Calochortus albus
2	*English rye-grass	Lolium perenne
2	southern foothill penstemon	Penstemon heterophyllus var. australis
3	tawny popcorn flower	Plagiobothrys fulvus
3	common lomatium	Lomatium utriculatum
3	brown microseris	Stebbinsoseris heterocarpa
3	Bolander's water-starwort	Callitriche heterophylla var. bolanderi
3	purslane speedwell	Veronica peregrina ssp. xalapensis
3	clover fern	Marsilea vestita ssp. vestita
3	red-skinned onion	Allium haematochiton
4	*brome fescue	Vulpia bromoides
4	warty spurge	Euphorbia spathulata
4	*brass-buttons	Cotula coronopifolia
5	*Mediterranean barley	Hordeum marinum ssp. gussoneanum
5	spike primrose	Epilobium densiflorum
5	chocolate lily	Fritillaria biflora var. biflora
5	gray sage	Salvia apiana X S. mellifera
6	shining peppergrass	Lepidium nitidum var. nitidum
6	western buttercup	Ranunculus occidentalis

Visit Date	Visit #	# taxa	# "?"	# "sp"	# "~"	# "ssp"
12/15/2001	1	70	9			1
2/4/2002	2	87	8			1
2/21/2002	3	120	8			1
3/4/2002	4	132	14			1
3/13/2002	5	129	7			1
3/20/2002	6	130	2			1
4/3/2002	7
4/10/2002	8	134	4			1
4/17/2002	9	136	4			1
4/28/2002	10	139	3			1
5/5/2002	11	139	3			1
5/10/2002	12	139	0		1	1
12/14/2002	13	143	1	0	1	0
1/4/2003	14
1/17/2003	15
1/26/2003	16
2/14/2003	17	149	0	0	4	2
2/28/2003	18	151	0	1	3	2
3/6/2003	19	152	0	1	3	1
3/12/2003	20	152	0	1	2	1
3/19/2003	21	155	0	0	2	1
3/24/2003	22	155	0	0	2	1
3/29/2003	23
4/30/2003	24
5/15/2003	25
6/8/2003	26	172	1	2	1	0
3/30/2004	27	171	0	2	1	0
3/10/2005	28
3/16/2005	29
4/7/2005	30	176	0	0	0	1
4/13/2005	31	177	0	0	0	0
5/26/2005	32	177	0	0	0	0
6/19/2005	33	178	0	0	0	0
8/18/2005	34	179	0	0	1	0
10/15/2005	35	178	0	1	0	0
10/15/2005	35	186	0	1	1	0

Mile	S	#	id?	Common Name	Latin Name	#here	#all
0.00				Trailhead on Via Volcano
0.00	b			(puncture-vine, Tribulus terrestris)
0.00	r		sp	(tumble pigweed, Amaranthus albus; annual goosefoot, Chenopodium sp.; telegraph weed, Heterotheca grandiflora; horseweed, Conyza canadensis; Rhodes grass, Chloris gayana)
0.00	r	1		*foxtail barley	Hordeum murinum ssp. glaucum⁺	40 / 2	13
0.00	r	2		*ripgut brome	Bromus diandrus	99 / 9	51
0.00	r	3		*shortpod mustard	Hirschfeldia incana	99 / 9	51
0.00	c	4		*knotweed	Polygonum arenastrum	20 / 5	18
0.00	r	5		*Crete weed	Hedypnois cretica	5 / 2	19
0.00	r	6		*short-fruited filaree	Erodium brachycarpum	99 / 9	14
0.00	r	7		*wild oats	Avena fatua	99 / 9	26
0.00	l	8		*sow thistle	Sonchus oleraceus	20 / 5	41
0.00	r	9		blue dicks	Dichelostemma capitatum ssp. capitatum	99 / 9	46
0.00	r	10		checkerbloom	Sidalcea malviflora ssp. sparsifolia	99 / 9	25
0.00	l	11		*soft chess	Bromus hordeaceus	99 / 9	40
0.00		12		*tocalote	Centaurea melitensis	99 / 5	45
0.00	r	13		graceful tarplant	Holocarpha virgata ssp. elongata	99 / 9	14
0.00	r	14		rusty-haired popcorn flower	Plagiobothrys nothofulvus	99 / 9	12
0.00		15		splendid mariposa lily	Calochortus splendens	99 / 9	19
0.00	r	16		California plantain	Plantago erecta	1 / 1	13
0.00	r	17		soap plant	Chlorogalum pomeridianum var. pomeridianum	20 / 5	18
0.00	b	18		*red brome	Bromus madritensis ssp. rubens	99 / 9	52
0.00	r	19		*pineapple weed	Chamomilla suaveolens	10 / 3	19
0.00	r	20		*smooth cat's ear	Hypochaeris glabra	99 / 9	35
0.00		21		dove weed	Eremocarpus setigerus	30 / 5	24
0.00	r	22		shining peppergrass	Lepidium nitidum var. nitidum	99 / 3	6
0.00	l	23		dwarf lupine	Lupinus bicolor	99 / 9	29
0.00	l	24		*Italian rye-grass	Lolium multiflorum	99 / 9	17
0.00	r	25		purple clarkia	Clarkia purpurea ssp. quadrivulnera	99 / 9	25
0.00	l	26		*California burclover	Medicago polymorpha	50 / 4	40
0.00	b	27		balloon clover	Trifolium depauperatum var. truncatum	99 / 9	7
0.01	l			Sign: "Reserve Fees $2 adults, $1 children"
0.01	r	28		Spanish clover	Lotus purshianus var. purshianus	30 / 4	31
0.01	r	29		earth brodiaea	Brodiaea terrestris ssp. kernensis	99 / 9	7
0.01	l	30		muilla	Muilla maritima	99 / 9	7
0.01	r	31		purple sanicle	Sanicula bipinnatifida	99 / 9	11
0.01	r	32		tawny popcorn flower	Plagiobothrys fulvus⁺	99 / 9	3
0.01	r	33		ground pink	Linanthus dianthiflorus	99 / 9	9
0.01	l	34		goldfields	Lasthenia californica	99 / 9	12
0.01	r	35		common lomatium	Lomatium utriculatum	50 / 5	3
0.01	r	36		red maids	Calandrinia ciliata	20 / 3	18
0.01	l			Display Board
0.01		37		*nit grass	Gastridium ventricosum	99 / 9	24
0.01	b	38		*hairy rattail fescue	Vulpia myuros var. hirsuta	99 / 9	18
0.01	r	39		*slender wild oats	Avena barbata	50 / 3	39
0.01	r	40		purple needlegrass	Nassella pulchra	99 / 9	19
0.01	r	41		*prickly lettuce	Lactuca serriola	99 / 9	42
0.01	l	42		yellow carpet	Blennosperma nanum var. nanum	99 / 9	1
0.01	l			Sign: "Vernal Pool Trail (ahead); To Large Pool 0.7 mi; To Adobes 1.7 mi"
0.01	l	43		pygmy-weed	Crassula connata	50 / 2	28
0.01	l	44		silver puffs	Uropappus lindleyi	99 / 9	26
0.01	r	45		*mouse-ear chickweed	Cerastium glomeratum	5 / 2	19
0.01	r	46		owl's-clover	Castilleja densiflora⁺	99 / 5	7
0.01	r	47		*windmill pink	Silene gallica	20 / 2	33
0.01	r	48		*narrowleaf filago	Filago gallica	20 / 2	45
0.01	r	49		brown microseris	Stebbinsoseris heterocarpa	50 / 3	3
0.01	l			(San Diego wreathplant, Stephanomeria diegensis)
0.02	b	50		California-aster	Lessingia filaginifolia var. filaginifolia	30 / 9	51
0.03	r	51		*redstem filaree	Erodium cicutarium	20 / 2	55
0.04	l			(coast live oak, Quercus agrifolia var. agrifolia)
0.04	r	52		vinegar weed	Trichostema lanceolatum	20 / 5	14
0.05	l	53		one-sided bluegrass	Poa secunda ssp. secunda	10 / 3	23
0.05		54		*goldentop	Lamarckia aurea	99 / 3	21
0.05	r	55		sharp-toothed sanicle	Sanicula arguta	20 / 6	16
0.06	l	56		San Diego birdsfoot lotus	Lotus hamatus	5 / 1	24
0.06	l	57		bajada lupine	Lupinus concinnus	30 / 3	11
0.06	l	58		long-stemmed buckwheat	Eriogonum elongatum var. elongatum	20 / 3	27
0.06	l	59		angel's gilia	Gilia angelensis	40 / 1	14
0.06	l			(In prickly-pear: Vasey's prickly-pear, Opuntia vaseyi; bull thistle, Cirsium vulgare; California fuchsia, Epilobium canum ssp. canum; wild cucumber, Marah macrocarpus var. macrocarpus; and poison oak, Toxicodendron diversilobum*.
		60		*sand spurrey	Spergularia bocconei⁺	10 / 2	13
0.09	r	61		fringe-pod	Thysanocarpus curvipes	10 / 2	9
	l	62		rattlesnake weed	Daucus pusillus	10 / 2	28
	r	63		*scarlet pimpernel	Anagallis arvensis	10 / 2	32
0.10	l	64		San Diego morning-glory	Calystegia macrostegia ssp. tenuifolia⁺	10 / 3	18
	l	65		*hedge mustard	Sisymbrium officinale	30 / 2	20
	r	66		*white sweetclover	Melilotus albus	10 / 1	7
0.11	l			(large Engelmann oak, Quercus engelmannii)
0.11	r	67		*brome fescue	Vulpia bromoides	/	4
0.11	r	68		blue larkspur	Delphinium parryi ssp. parryi	20 / 3	13
0.12	r	69		blue-eyed grass	Sisyrinchium bellum	99 / 9	19
0.12	b	70		johnny jump-up	Viola pedunculata	99 / 9	16
0.12	l			Jct. Los Santos Trail. Enter mustard and wild oats "desert", crowding out natives, mostly on right.
0.12	l			(California buckwheat, Eriogonum fasciculatum var. foliolosum)
0.13	l			(telegraph weed, Heterotheca grandiflora)
0.14	l	71		*curly dock	Rumex crispus	99 / 5	23
0.14	r			(California everlasting in prickly pear)
0.15	l	72		Vasey's prickly-pear	Opuntia vaseyi⁺	10 / 2	24
0.15	l			(coast live oak, Quercus agrifolia var. agrifolia)
0.16	r	73		San Diego wreathplant	Stephanomeria diegensis	20 / 4	21
	r	74		pin-point clover	Trifolium gracilentum var. gracilentum	10 / 2	8
	r	75		small-head field clover	Trifolium microcephalum	10 / 1	10
		76		shooting star	Dodecatheon clevelandii ssp. clevelandii	99 / 3	11
	l			Check specimens here for bloom to see if they are common spikerush, , or wire rush, Juncus balticus
0.20	l	77		*prickly sow thistle	Sonchus asper ssp. asper	/ 1	30
0.20	l			Badger holes appeared here July 2002; nearly filled in by gophers in December 2002
0.20	r	78		*Mediterranean barley	Hordeum marinum ssp. gussoneanum	50 / 2	5
0.20	r	79		warty spurge	Euphorbia spathulata	99 / 9	4
0.21	r			Jct. short path to old percolation pit, now a mini-vernal pool, and ok to visit. Next 7 taxa at perc pit
0.21		80		hooked popcorn flower	Plagiobothrys undulatus	99 / 2	1
0.21		81		Bolander's water-starwort	Callitriche heterophylla var. bolanderi	99 / 2	3
0.21		82		woolly marbles	Psilocarphus brevissimus var. brevissimus	50 / 2	2
0.21		83		spike primrose	Epilobium densiflorum	10 / 1	5
0.21		84		prostrate navarretia	Navarretia prostrata	5 / 1	1
0.21		85		common spikerush	Eleocharis macrostachya	99 / 3	11
0.21		86		thread-leaved brodiaea	Brodiaea filifolia	50 / 4	2
0.22				Back on main trail
0.25	l			(large Engelmann oak, Quercus engelmannii)
0.26	l			Outer part of curve of trail is one of the best shooting star fields, accompanied by blennosperma and goldfields.
0.29	l	87		Two young Engelmann oaks	Quercus engelmannii	10 / 5	23
	r			(Check for Plagiobothrys arizonicus or intergrade with it)
0.34	r	88		western buttercup	Ranunculus occidentalis⁺	50 / 9	6
0.34				Curve left
0.35	b	89		California poppy	Eschscholzia californica	30 / 3	29
		90		*long-beaked filaree	Erodium botrys	50 / 5	11
	r			Pristine field of purple needlegrass, Nassella pulchra
0.40	l			Famous "see-through" tree shell in distance on left, with just bark left standing.
0.40	r	91		*(gazania)	Gazania X (mounding hybrid)⁺	1 / 1	6
0.42	l	92		nodding needlegrass	Nassella cernua	99 / 5	16
0.42	l			Jct. Trans Preserve Trail
0.43	l			(coyote bush, Baccharis pilularis)
0.44	r	93		white everlasting	Gnaphalium canescens ssp. microcephalum	7 / 3	36
0.45	l	94		Mexican rush	Juncus mexicanus	20 / 1	16
0.46	r	95		*winter vetch	Vicia villosa ssp. varia⁺	99 / 1	19
0.47	l			Display Board with story of Vernal Pool on one side, basalt weathering on the other.
0.48	l			(laurel sumac, Malosma laurina))
0.49	l			First large Engelmann oak, Quercus engelmannii, on the trail
0.49	l	96		laurel sumac	Malosma laurina	10 / 3	42
0.50	l	97		California everlasting	Gnaphalium californicum⁺	30 / 4	42
0.55				Trail bends left
		98		*tumble pigweed	Amaranthus albus	3 / 2	12
0.61	r	99		*(bull thistle)	Cirsium vulgare⁺	1 / 1	17
0.63	l			Begin main population of thread-leaved brodiaea, Brodiaea filifolia
0.64				Bench; Jct. loop trail around pool. Go right to pool, taking the loop counter-clockwise.
0.65	b	100		slender tarweed	Hemizonia fasciculata	20 / 2	17
0.66				Begin boardwalk. The hooked popcorn flower makes the white color at the Pool.
0.66	r	101		purslane speedwell	Veronica peregrina ssp. xalapensis	10 / 2	3
0.66	r	102		common bedstraw	Galium aparine⁺	20 / 2	38
0.66	l	103		*rabbits-foot grass	Polypogon monspeliensis	20 / 2	22
0.66	r	104		annual hairgrass	Deschampsia danthonioides	20 / 1	1
0.66	l	105		San Diego button-celery	Eryngium aristulatum var. parishii	50 / 1	2
0.66	r	106		*brass-buttons	Cotula coronopifolia	10 / 2	4
0.66	b	107		spotted downingia	Downingia bella	99 / 1	1
0.67	r	108		smooth goldfields	Lasthenia glaberrima	5 / 1	1
0.67	r	109		willow weed	Polygonum lapathifolium⁺	1 / 1	2
0.67	b	110		alkali mallow	Malvella leprosa	40 / 2	1
0.68	l	111		knot grass	Paspalum distichum	99 / 2	7
0.68	r	112		Orcutt's quillwort	Isoetes orcuttii	1 / 1	1
0.68				Center of boardwalk
0.68	r	113		water crowfoot	Ranunculus aquatilis var. capillaceus	5 / 1	2
0.68	c	114		*grass poly	Lythrum hyssopifolia	10 / 1	14
0.68	r	115		clover fern	Marsilea vestita ssp. vestita	10 / 1	3
0.69	r	116		*Carolina canarygrass	Phalaris caroliniana	1 / 1	2
0.71	b	117		*cut-leaved geranium	Geranium dissectum	20 / 1	13
0.71				End boardwalk; continue on loop trail
0.71	l			Blennosperma and goldfields patch
0.73	r	118		western toad rush	Juncus bufonius var. occidentalis	10 / 1	2
0.74				(Check for different Plagiobothrys, collinus?)
0.79				Spot from which pool pictures were taken for 2002 onward.
0.83				End loop trail; continue on Vernal Pool Trail to the right.
0.85				Spot from which pool pictures were taken for 2001.
0.85	r			(In the prickly pear: coast-range melic, Melica imperfecta; bee plant, Scrophularia californica ssp. floribunda; and bicolored everlasting, Gnaphalium bicolor.)
0.88	r			Badger holes appeared here April 2002, the first badger holes on the trail in my experience (since 1996). Nearly filled in by gophers in December 2002
0.89	r	119		*spring vetch	Vicia sativa ssp. sativa	30 / 3	6
0.91	l			Second set of April 2002 badger holes
0.91				End wheelchair-accessible portion of trail
0.91	l	120		coast live oak	Quercus agrifolia var. agrifolia	1 / 1	42
0.91	l			Engelmann oak growing inside the coast live oak
0.92	l	121		coast-range melic	Melica imperfecta	10 / 2	43
0.92	l			(Flat-topped bent Englemann oak off trail. It probably grew under another tree that is no longer present.)
	l			(hollyleaf redberry, Rhamnus ilicifolia, in prickly pear)
0.93	l			View of Elsinore peak with ~6 antenna on it at ~10 o'clock
	l			(white sage, Salvia apiana)
0.94	l	122		bush lupine	Lupinus excubitus var. hallii	5 / 1	10
0.94	l	123		lanceleaf dudleya	Dudleya lanceolata	1 / 1	20
0.95	l	124		bird's-foot fern	Pellaea mucronata var. mucronata	1 / 1	30
1.00	b			Field of shooting stars
1.01	r			White variant of owl's-clover, Castilleja densiflora
1.04	r	125		tomcat clover	Trifolium willdenovii	20 / 1	17
1.04	r			California everlasting	Gnaphalium californicum⁺	/
1.05				Trail turns right and drops off top of Mesa de Colorado
1.05	l	126		*white-stemmed filaree	Erodium moschatum	20 / 1	20
1.05	l	127		coffee fern	Pellaea andromedifolia	1 / 1	22
1.05	l	128		caterpillar phacelia	Phacelia cicutaria var. hispida	50 / 1	16
1.05	b	129		wild-cucumber	Marah macrocarpus var. macrocarpus	5 / 1	44
1.05	l	130		leafy daisy	Erigeron foliosus var. foliosus	1 / 1	43
1.06	l	131		poison oak	Toxicodendron diversilobum	5 / 1	43
1.06	r	132		California fuchsia	Epilobium canum ssp. canum	1 / 1	20
1.06	r			common bedstraw	Galium aparine⁺	/
1.06	l			(Nice stand of somewhat hidden blue dicks, Dichelostemma capitatum ssp. capitatum, San Diego pea, Lathyrus vestitus var. alefeldii, and south coast morning-glory, Calystegia macrostegia ssp. intermedia.)
1.06	r			(white everlasting, Gnaphalium canescens ssp. microcephalum)
1.07	l	133		bicolored everlasting	Gnaphalium bicolor	5 / 2	29
1.07	r	134		slender vetch	Vicia hassei	10 / 3	6
1.07	r	135		pellitory	Parietaria hespera var. hespera	1 / 1	6
1.07	l	136		white-flowering currant	Ribes indecorum	10 / 3	22
1.07	r	137		southern miner's lettuce	Claytonia perfoliata ssp. mexicana	20 / 2	25
1.07	r	138		*hedge parsley	Torilis nodosa	20 / 1	14
1.07	r	139		San Diego pea	Lathyrus vestitus var. alefeldii	2 / 2	21
1.07	r	140		south coast morning-glory	Calystegia macrostegia ssp. intermedia⁺	10 / 1	19
1.07	r	141		blue wildrye	Elymus glaucus ssp. glaucus	20 / 1	21
1.08		142		*(milk thistle)	Silybum marianum⁺	1 / 1	9
1.09	r	143		climbing bedstraw	Galium nuttallii ssp. nuttallii	10 / 3	30
1.09	r			Bench
1.11	r			Field of purple sanicle
1.12	l	144		toyon	Heteromeles arbutifolia	10 / 2	44
1.14	l			(chocolate lily, Fritillaria biflora var. biflora)
1.15	r			(Engelmann oak, Quercus engelmannii, with a few crown galls, lost two major limbs from main trunk in summer 2005)
1.17				Enter Fairy Lane, a short section of chaparral / coastal sage scrub lined with Fairy Lanterns (in season).
1.17	b	145		white fairy lantern	Calochortus albus	50 / 2	2
1.17	b	146		Torrey's scrub oak	Quercus acutidens	20 / 2	26
1.17	r	147		sticky cinquefoil	Potentilla glandulosa ssp. glandulosa	20 / 2	17
1.18	b	148		Pacific sanicle	Sanicula crassicaulis	5 / 2	20
1.18	r	149		narrowleaf bedstraw	Galium angustifolium ssp. angustifolium	10 / 2	48
1.18	r	150		saw-toothed goldenbush	Hazardia squarrosa var. grindelioides	20 / 2	35
1.18	b	151		deerweed	Lotus scoparius var. scoparius	20 / 2	29
1.18	r	152		bush monkeyflower	Mimulus aurantiacus	10 / 1	42
1.18	l			(sacapellote, Acourtia microcephala)
1.20	r	153		black sage	Salvia mellifera	30 / 2	40
1.20	r	154		sugar bush	Rhus ovata⁺	5 / 2	25
1.20	l	155		*purple false-brome	Brachypodium distachyon	20 / 1	6
1.20	b	156		chamise	Adenostoma fasciculatum	20 / 1	37
1.20	r	157		southern honeysuckle	Lonicera subspicata var. denudata	5 / 2	40
1.20	r	158		heartleaf penstemon	Keckiella cordifolia	2 / 2	27
1.22	r	159		small-flower western flax	Hesperolinon micranthum	50 / 3	1
1.23	l	160		chocolate lily	Fritillaria biflora var. biflora	50 / 9	5
1.23		161		yellow mariposa lily	Calochortus weedii var. weedii	10 / 1	10
1.23	l	162		golden yarrow	Eriophyllum confertiflorum var. confertiflorum	20 / 2	55
1.24	b	163		red-skinned onion	Allium haematochiton	10 / 3	3
1.24		164		*English rye-grass	Lolium perenne	1 / 1	2
1.24				Local low point on trail
1.24	r			(chocolate lily, Fritillaria biflora var. biflora in field of red-skinned onion, Allium haematochiton)
1.24	l	165		southern foothill penstemon	Penstemon heterophyllus var. australis	1 / 1	2
1.24	r	166		foothill needlegrass	Nassella lepida	20 / 1	20
1.27	l	167		Eastwood manzanita	Arctostaphylos glandulosa ssp. zacaensis	5 / 2	11
1.28	r	168		white-leaf monardella	Monardella hypoleuca ssp. hypoleuca	5 / 1	1
1.30	r	169		hollyleaf redberry	Rhamnus ilicifolia	5 / 1	43
1.30				Cross drainage
	l			(One or two olive trees, Olea europaea* present in 2001 were removed in 2002.)
1.31				Local high point on trail
1.32				Interesting mushrooms, light brown with dark brown edge.
1.33	r	170		white sage	Salvia apiana	1 / 1	38
1.33	r	171		gray sage	Salvia apiana X S. mellifera⁺	1 / 1	5
1.34				Local low point on trail
1.35	r	172		narrow-leaved miner's lettuce	Claytonia parviflora ssp. parviflora	2 / 1	19
1.35	r			(California peony, Paeonia californica)
1.35				Local high point on trail
1.36	l	173		blue elderberry	Sambucus mexicana	1 / 1	48
1.36				End chaparral
1.37	b			First large patch of chocolate lily, Fritillaria biflora var. biflora
1.37				Trail was rerouted in 2004 to eliminate the mudpit section. The new trail has many more chocolate lilies on it!
1.44	l	174		slender madia	Madia gracilis	3 / 1	19
1.45	r	175		*olive	Olea europaea	1 / 1	10
1.48				Cross small drainage
1.52	r	176		strigose lotus	Lotus strigosus	10 / 1	33
1.53				Trail zigzags left
1.54	r			White variant of dwarf lupine, Lupinus bicolor
1.54	b	177		Indian milkweed	Asclepias eriocarpa	1 / 1	17
1.57				Jct. Ranch Road. Turn right, toward adobes
1.59	l	178		*rose clover	Trifolium hirtum	2 / 1	12
1.59	r	179		western ragweed	Ambrosia psilostachya	10 / 1	39
1.61	b	180		horseweed	Conyza canadensis	5 / 1	40
1.61	r			Jct. old Vernal Pool Trail; plants at Adobes not described here; most have been planted.
1.62	l	181		*little horseweed	Conyza bonariensis	5 / 1	18
1.64	l			(horehound, Marrubium vulgare)
1.66	l	182		fragrant everlasting	Gnaphalium canescens ssp. beneolens	1 / 1	24
1.66	l	183	~	*Chinese elm	Ulmus parvifolia	2 / 1	2
1.67	r	184		*Bermuda grass	Cynodon dactylon	10 / 2	33
1.67	r	185		*English plantain	Plantago lanceolata	5 / 1	20
1.67				Jct. Adobes; guide doesn't include plants at Adobes, and resumes back at the jct. with the Vernal Pool Trail. There is a porta-potty at Adobes.
1.77				Jct. Vernal Pool Trail; guide continues west along Ranch Road toward Trans-Preserve Trail
1.92	b	186		stinking gourd	Cucurbita foetidissima	5 / 1	9
2.06				Road curves right 90°
2.12				Jct. Hidden Valley Road; turn left
2.19				Jct. S. Trans Preserve Trail; end guide

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Plant Trail Guides For The Santa Rosa Plateau
Field Guide to the Santa Rosa Plateau: Plants

Copyright © 2002-2006 by Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to me at this source:
http://tchester.org/srp/plants/guides/vp.html
Comments and feedback: Tom Chester
Updated 19 April 2006.