The Vascular Flora of Plum Canyon, Anza-Borrego Desert State Park

Larry Hendrickson, Tom Chester, James Dillane and Kate Harper

The "plums" of Plum Canyon are actually desert apricot, Prunus fremontii. Picture taken at the parking area at the end of the dirt road up Plum Canyon on 12 December 2012, of plants leafed out following monsoonal rain in August 2012. Most of the year the plants are leafless. Click on the picture to get a larger version.

Google Earth View
Botanical Highlights
Procedure For Compiling The Checklist
Species Checklist


Plum Canyon is a delightful canyon in the western part of Anza-Borrego Desert State Park. It is the first major canyon on the right (south) seen by people traveling from western San Diego County as they leave Sentenac Gorge and emerge into the desert proper. These eastbound travelers usually notice the showy red blossoms of chuparosa, Justicia californica, for the first time where Plum Canyon wash meets Highway 78 (SR78), where the first large population occurs.

As a result of its location in the Desert Transition Zone, Plum Canyon has an interesting collection of species, with good diversity. The plant checklist below contains 175 taxa, which range from lower desert species to even a few coastal species. The Canyon contains the westernmost extent at this latitude of some desert species, such as Carlowrightia arizonica, Arizona carlowrightia, and the easternmost extent of some coastal species, such as Selaginella bigelovii, Bigelow's spike-moss.

Even better, this Canyon has few non-native species. There are only four non-native species in its plant list (five if you count the possible non-native Mollugo cerviana), and they are not very abundant in the canyon. The biggest scourge of the desert, Brassica tournefortii, Asian mustard, is only found along SR78 at the bottom of Plum Canyon Wash. An aggressive weeding campaign led by the first author has kept this species mostly out of Plum Canyon.

The origin of the name Plum Canyon is not known for certain, but it is most likely to come from the abundant desert apricot, Prunus fremontii, in the canyon. Cultivated plums and apricots are very closely related, both in the genus Prunus, distinguished in Bailey as follows:

C. Fruit glabrous, usually with a slender pedicel that remains with it, the stone not prominently furrowed ... Plums
CC. Fruit pubescent, the pedicel short and separating at maturity, the stone usually furrowed on the margin... Apricots

Prunus fremontii has pubescent (= very short hairy) fruit, which clearly makes it an apricot, not a plum. But perhaps someone thought the dark color of the fruit at times was closer to a plum, and named the canyon for that.

This canyon is a favorite place for CNPS plant tours led by the first author; see photos from the March 2011 trip.

The entrance to Plum Canyon is 4.1 miles east of Scissors Crossing, and 2.7 miles west of the turnoff to Tamarisk Grove Campground and Yaqui Pass Road (S3).

Most passenger cars can easily drive the 1.6 miles up the sandy non-paved road from SR78 to a parking area where the canyon walls close in, preventing further car travel up the canyon (take the right-hand fork at mile 1.35). A fairly easy ~3 mile roundtrip, with 400 feet of elevation gain, walk up the canyon along the California Riding and Hiking Trail leads to a saddle overlooking Earthquake / Shelter Valley.

An even more interesting botanical trip is to start walking at SR78, to experience the full transition from the lower-elevation desert proper to the lower part of the desert transition zone near the top of the canyon. That walk is roughly 6 miles roundtrip with 900 feet of elevation gain, from 1700 feet to 2600 feet.

For botanists, one of the things that makes the walk along the entire canyon / wash special is that one is following the footsteps of California's first botanist, Willis Linn Jepson, the "Botany Man", who wrote the first manual on the flora of California.

Lower Plum Canyon was called Wagon Wash in those days, and was part of the wagon route from Earthquake / Shelter Valley to Yaqui Well. The old route heading west branched at the top of Plum Canyon; the California Riding and Hiking Trail follows one of the branches south from Upper Plum Canyon to North Pinyon Mountain Road in Earthquake / Shelter Valley. The other branch headed west down to the Sentenac Cienega area. (see map of Wagon Wash; Wray 2004 The Historic Backcountry: A geographic Guide to the Historic Places of the San Diego County Mountains and the Colorado Desert; and the 1913 topo map with the vegetation mapping showing the routes.

Today it seems like this route could never have been passable by wagons in some places. However, at least some of the rockslides creating impassable stretches appear fresh, and may have occurred after the wagon route was abandoned. In fact, the construction of the wagon route may have precipitated at least some of these rockslides by undercutting the slopes.

There is at least one area of upper Plum Canyon where the trace of the old wagon road is still visible, on the stretch just below the saddle (see also version with the old wagon road marked).

See Road Timeline in the Borrego Desert Area for dates of road construction that bypassed this Wagon Road.

Some links to photographs of Plum Canyon and its plant species:

Google Earth View

Google Earth View of Plum Canyon and points east as seen using a vantage point at 6000 feet elevation from just south of Scissors Crossing looking northeast. Some features are labeled (see text below). The North direction is indicated in the upper right corner. Click on the picture to get a larger version. See also unlabeled version.

In the Google Earth View, the Plum Canyon drainage is outlined in red, with two saddles on the ridgeline dividing it from Earthquake / Shelter Valley shown in red diamonds. Blue lines show our survey routes on 12 and 21 December 2012. The northernmost route corresponds to the old Wagon Road built by John McCain sometime after 1895 and prior to 1913, which was only superceded in 1922 when SR78 was finished through Sentenac Gorge. Many traces of the old Wagon Road are still visible along most of its route on the Sentenac Cienega side of the Plum Canyon Saddle, but only a few traces are visible on the hike from the Plum Canyon Parking Area to the northernmost saddle.

The short Plum Canyon hike from the Parking Area goes to the northernmost of the two saddles shown on the map. However, there are no signs telling the hiker when to exit the main canyon in order to reach it. As a result, many hikers end up continuing up the main wash in a direction away from the saddle overlooking Earthquake / Shelter Valley! Or they take the California Riding and Hiking Trail to the southwest ridgeline of Plum Canyon. Or if the first turnoff is missed, but the second turnoff is taken, hikers end up at the southern of the two saddles shown on the map, which is just a bit longer.

Botanical Highlights

Willis Linn Jepson's Comments

As mentioned above, one of the botanical highlights is being in an area where Jepson himself collected 72 vouchers in 1920 and 1928. His fairly extensive notes in his field books, along with his vouchers, reveal what it was like 85 and 93 years ago. After our next survey in prime time, to make our observed list more complete, we'll do a detailed comparison of what we see now to conditions nearly a century earlier (see also below).

Jepson collected 72 vouchers from Wagon Wash in April 1920 and April 1928. His Field Books that describe the area, including the geography, plants and animals, and his collections, are all online:

Jepson's description of Plum Canyon = Wagon Wash from 1920 is still an accurate overview today:

This wash, from its junction with the San Felipe region to the summit of the pass is about 2 3/4 miles. The lowest half mile is Smoke Bush (Dalea spinosa = Psorothamnus spinosus), very much scattered. The next 1 1/2 miles is Hyptis emoryi which is very abundant and gives a distinct character to this part of the wash. The next half-mile is Desert Apricot (no. 8769; Prunus fremontii) which is abundant; the last 1/8 mile is no. 8772, Coleogyne ramosissima, dominant at very summit; but not extending down far. The 1/8 mile below it is most interesting for the Bernardia (no. 8775). [vol. 37, p. 157]

Jepson's notebook has Ayenia instead of Bernardia, but his voucher is determined as Bernardia, which is indeed an interesting species at that point in the Canyon today. We have not yet found any Ayenia at that point in Plum Canyon.

When Jepson said not extending down far for the Coleogyne ramosissima, he meant within Plum Canyon, on the east side of the summit, since that species extends all the way down to Sentenac Cienega on the west side of the summit.

And Jepson's admonition that desert botany requires careful scrutiny is just as valid today:

Many things show only a single individual, so far as we notice. For example, only one individual of Cassia armata Wats. was found. The desert, therefore, requires careful scrutiny - all the more in that certain things are everywhere so omnipresent. It is, too, easy to walk over inconspicuous plants in the desert sands, such as Nemacladus, no. 12,486. [vol. 37, p. 202]

Even in 1920 Erodium cicutarium, redstem filaree, was a problem. (In fact, the earliest botanists to explore California often found it.) Jepson commented:

I have not mentioned Erodium cicutarium this trip very much but everywhere in the desert one finds it. When the sandy granite is very dry it covers the country with small plants; even where desert plants (annuals) do not get along well. [vol. 37, pp. 152-153.]

Jepson clearly enjoyed Plum Canyon. In 1928 he wrote:

We move down the next day, Apr. 20, through Sentenac Canon, and turn up, off the road, into the lower part of the Wagon Wash, a hundred yards or more, and make camp. It is still very windy but we spend the day botanizing in the wash. In this locality I collect nos. 12,473 to 12,510. We spend the day and night here. It is a fine camp in a fine country for botanizing. [vol. 46, pages 195-196]

One big difference from 1928 is that we have not yet found Eriogonum plumatella in Plum Canyon. Jepson wrote:

There is a great deal of this in the wash called Wagon Wash. It forms colonies and makes a marked stand in places where there is little other vegetation. It also grows as scattered individuals on the first bench above the wash (3 to 5 ft. higher) scattered amongst the creosote bushes and cacti in open places. [Jepson originally called this E. palmeri, but crossed the name out on p. 201 and replaced it with E. plumatella; vol. 46, p. 207]

In our surveys of the length of Plum Canyon on 12, 21, and 28 December 2012, and 2 January 2012, we found not a single individual of E. plumatella! Nor has the first author found any in his extensive explorations of this Canyon. We did find a single plant in the wash immediately east of Plum Canyon Wash, but none others in a 7 mile exploration of that wash and canyon.

It is possible that in 1928 Jepson was referring to San Felipe Wash in the vicinity of Plum Canyon. San Felipe Wash was probably the wagon route after descending Plum Canyon.

Other Botanical Highlights

The last two highlights show that there is still much to be learned about the flora of California, with surprises waiting in many areas.

Both of these two species are disjuncts from Arizona, which shows that this area has some additional affinity to the flora of southwest Arizona other than the lower-elevation widespread species such as creosote and ocotillo. These disjunct species are separated from their Arizona siblings with a large area in-between currently without any of these species. The connection probably occurs during the cool phase of the Ice Ages, which lasts some 90% of one glacial cycle, when these species may expand their ranges so that the Arizona and California populations approach each other more closely. There have been roughly 24 such cycles, each lasting ~100,000 years, in the last 2.4 million years since the Ice Ages began.

Long-distance dispersal is also a possibility, but the number of other disjuncts, such as Arctostaphylos pringlei at higher elevations, makes a geographic connection of the range of these species during wetter, cooler times more likely.

Procedure For Compiling The Checklist

The Checklist was compiled from two sources:

The areas surveyed by the 12 and 21 December 2012 fieldwork are shown by the blue lines in the Google Earth View shown above.

The fieldwork on 21 December 2012 was primarily to find traces of the old Wagon Road, with only incidental botanizing.

The 12 December 2012 fieldwork was used to compile a species list, with a GPS location for at least one occurrence of every species, and to estimate abundances for each observed species. Note that the fieldwork list is extremely incomplete for annuals and perennials, since it was made from field trips at the worst-possible time of year, in late fall, which covered only a small area of the canyon along the main hiking route from SR78 to one of the several saddles at the top. We did not attempt to identify dead annuals except for those whose determinations were unambiguous from their remnants. The abundances for those dead annuals may be severely underestimated.

A species list was compiled from the 24 December 2010 fieldwork, but no GPS locations or abundances were recorded.

Species lists were not compiled from the other fieldwork. The 21 December 2012 and 2 January 2013 fieldwork noted any new species, and increased the abundances of a number of species. Notes and photographs from the other trips were used to add species to the plant list.

The 27 March 2011 and 28 December 2012 fieldwork was done primarily in the canyon directly east of Plum Canyon. Because the Plum Canyon List is incomplete for annuals and perennials, species seen only in that canyon were added to the Plum Canyon list as target species, ones to be looked for in Plum Canyon, and so identified in the checklist below.

The fieldwork found 111 distinct taxa in Plum Canyon, plus five additional taxa from the canyon to the east, for a total of 116 taxa.

Vouchers were obtained from three separate searches:

Vouchers by Jepson were examined for "missing numbers", resulting in the addition of two vouchers.

Duplicate vouchers were removed, and the localities were reviewed manually to remove ones not in Plum Canyon. Six vouchers were badly georeferenced; 134 were clearly from outside Plum Canyon, with most in Sentenac Canyon or along SR78 outside the Plum Canyon area. 18 vouchers were from wash 300 yds W of Plum Canyon, which drains into the San Felipe River just upstream from Plum Canyon Wash, and hence were excluded.

Iti isn't clear whether the ten Jepson vouchers from 22 April 1928 were from the south fork of Plum Canyon, or from the entirely-separate canyon immediately east of Plum Canyon. Near SR78, the wash from the separate canyon is only 400 feet east of Plum Canyon Wash. He wrote:

In the morning Apr. 22 we drove back to Wagon Wash and I walked up the wash and into Mule-track Canon, the large canon to left of Wagon Wash Canon, and collected cacti.

Yet more confusingly, most of his vouchers from that day give Wagon Wash as the locality, with only two of the ten vouchers giving Mule-track Canyon in its locality, one of which also said Wagon Wash.

We have included his vouchers in this Checklist for now, but may exclude them in the future if some of the vouchered species are not found by us in the field in Plum Canyon. In the checklist below, two species were vouchered only from this set: Castilleja foliolosa and Pleurocoronis pluriseta.

One voucher determination was not accepted, of Opuntia wolfii = Cylindropuntia wolfii, by Jepson in 1928, JEPS66889. This species lives only much farther south, and hence this is unlikely to be the correct determination. It is most likely this is a specimen of C. ganderi, which was not recognized until 1938.

One voucher simply determined as Agave, also collected by Jepson in 1928, JEPS43125, was taken to be A. deserti, which is the only Agave species present in the Borrego Desert.

A few taxa were combined, when some were given as the species and others as the subspecies, and it was clear that only a single taxon was present.

That left 232 vouchers, of 122 distinct taxa.

The top collectors in Plum Canyon are:

# VouchersCollector(s)
78Larry Hendrickson
72W. L. Jepson
28Jeannie Gregory, John Gregory
22Jon P. Rebman, J. Gibson, A. Winner, & misc. botany vols.
10Bill Sullivan

The union of the checklist from the fieldwork and the vouchers contains 175 taxa. Of those 175 taxa, 63 taxa were found in both the fieldwork and the vouchers; 59 were found only in the vouchers; 48 were found only from the fieldwork; and 5 taxa are listed as target species after being found in the canyon to the east.

Nearly all of the 59 species that were vouchered, but not seen in our fieldwork, were annuals or perennials that one would not expect to see in December. All of the 48 species seen in the fieldwork, and the 5 target species, that do not have vouchers in Plum Canyon have vouchers elsewhere in the Borrego Desert; most of those have vouchers from the immediate area surrounding Plum Canyon.

Species Checklist

The Checklist follows the 2012 Jepson Manual Second Edition with only a few exceptions.

The Checklist is sorted first by the eight evolutionary categories (clades) used in the 2012 Second Edition Jepson Manual - lycophytes, ferns, etc., to eudicots and monocots - and then by family and scientific name. The clades are labeled in the Checklist. Note that this changes the order of presentation of the taxa from that of the 1993 First Edition.

The family name is abbreviated to the first six characters in order to save space in the table rows.

An asterisk before the Common Name indicates a non-native taxon.

The column labeled #Pls gives a minimum estimate of the number of plants from the field surveys, up to a maximum of 99 plants, for species seen in the field surveys for which abundances were noted. The main intent of this estimate is to indicate the species for which we found very few plants. If the species was added from Keir Morse's photographs from 5 March 2011, the column contains his initials, KM. If the species was seen only in the canyon immediately to the east, it is present in the list as a target species, one to be looked for in Plum Canyon, and the column contains TGT.

The column labeled #V gives the number of vouchers in Plum Canyon.

The scientific name is linked to the latest online Jepson Manual description for each species, which also gives the months in which each species flowers. That link also gives a map of where the species occurs in California; a plot of elevation vs. latitude for California; and a histogram of the voucher collections by month.

A few species may not have working links, if their names have been updated more recently (such as Mimulus diffusus, which is still listed under M. palmeri in the online flora), or if they are reserved-judgment taxa which are listed in the entry for another taxon name. However, as of 26 December 2012, the Jepson Manual links have all been updated to link to the parent species for the taxa without their own entries. Taxa linked to anything other than the Jepson Manual link for the full scientific name used below have been indicated with a ^ after the scientific name, and are discussed here.

The common name for most species in the checklist is linked to Calphotos to give pictures of most taxa. Of course, there is no guarantee that the Calphotos pictures are correctly identified.

Note that the link will not always return pictures, since not every species has pictures at Calphotos, and a number of species still have their Calphotos pictures under the Jepson Manual First Edition Names. Some links have been made to the Calphotos pictures using the First Edition Jepson Manual name, if there are no pictures under the Second Edition name. Of course, that may result in a link with no pictures if those the names of those Calphotos pix are updated in the future to the Second Edition names.

Note also that the links below will return only the specified taxon at Calphotos, and not any subtaxa; i.e., a link to Cryptantha barbigera will not return photos of Cryptantha barbigera var. barbigera. There may be additional pictures at Calphotos under a different scientific name such as the First Edition Jepson Manual name.

Some links, such as for Bochera perennans, go to special pages with more information on those species.

As of 26 December 2012, the picture links have all been updated to link to a page that has pictures. Taxa linked to anything other than the Calphotos page of their full scientific name used below have been indicated with a ^ after the common name.

If you find any links from either the scientific or common names below that do not work, please let us know so we can update them.

Version for printing, without lines and other text on this page: html (6 pages) or pdf Clickbook booklet (2 double-sided pages). (See printing instructions for an explanation of these options)

#FamilyScientific Name(*) Common Name#V#Pls
1SelagiSelaginella bigeloviiBigelow's spike-moss 99
2SelagiSelaginella eremophiladesert spike-moss 99
3PteridCheilanthes covilleibeady lipfern213
4PteridCheilanthes parryiwoolly lipfern599
5PteridCheilanthes viscidasticky lipfern 1
6PteridNotholaena californica ssp. californica^California cloak fern 1
7PteridPellaea mucronata var. mucronatabird's-foot fern 1
8CupresJuniperus californicaCalifornia juniper199
9EphedrEphedra asperaMormon tea299
10EphedrEphedra californicadesert tea 2
11AcanthCarlowrightia arizonicaArizona carlowrightia 15
12AcanthJusticia californicachuparosa799
13AmaranAmaranthus fimbriatusfringed amaranth 99
14ApiaceApiastrum angustifoliumwild celery2 
15ApiaceLomatium mohavenseMojave lomatium 8
16ApocynMatelea parvifoliaspearleaf116
17AsteraAcamptopappus sphaerocephalus var. sphaerocephalusgoldenhead1 
18AsteraAdenophyllum porophylloidesSan Felipe dogweed299
19AsteraAmbrosia dumosaburroweed199
20AsteraAmbrosia salsola var. salsolacheesebush^199
21AsteraArtemisia ludoviciana ssp. albulawhite mugwort 25
22AsteraBaccharis brachyphyllashort-leaved baccharis 70
23AsteraBahiopsis parishiiParish's viguiera299
24AsteraBebbia juncea var. asperasweetbush199
25AsteraBrickellia atractyloides var. argutaCalifornia spear-leaved brickellia 11
26AsteraBrickellia frutescensshrubby brickellia140
27AsteraChaenactis carphoclinia var. carphocliniapebble pincushion 5
28AsteraChaenactis fremontiiFremont pincushion199
29AsteraEncelia farinosabrittlebush199
30AsteraEricameria brachylepisboundary goldenbush^ 99
31AsteraEricameria paniculatablackbanded rabbitbrush 20
32AsteraEriophyllum wallacei var. rubellum^Wallace's woolly daisy^399
33AsteraGutierrezia californicaCalifornia matchweed 99
34AsteraLasthenia gracilisgoldfields199
35AsteraLogfia depressadwarf filago 1
36AsteraLogfia filaginoidesCalifornia filago 99
37AsteraMalacothrix glabratadesert dandelion299
38AsteraMonoptilon bellioidesdesert star1 
39AsteraPectis papposa var. papposachinch-weed 10
40AsteraPerityle emoryiEmory's rock-daisy11
41AsteraPleurocoronis plurisetaarrow-leaf1 
42AsteraPorophyllum gracileodora240
43AsteraRafinesquia neomexicanadesert chicory3 
44AsteraSenecio californicusCalifornia groundsel15
45AsteraStephanomeria exigua ssp. exiguaslender wreathplant 2
46AsteraStephanomeria pauciflorawire-lettuce 25
47AsteraTrichoptilium incisumyellow-head1 
48AsteraTrixis californica var. californicaCalifornia trixis430
49BignonChilopsis linearis ssp. arcuatadesert-willow 4
50BoragiAmsinckia intermediacommon fiddleneck125
51BoragiAmsinckia tessellata var. tessellatabristly fiddleneck TGT
52BoragiCryptantha barbigera var. barbigerabearded cryptantha35
53BoragiCryptantha decipiensgravel cryptantha1 
54BoragiCryptantha micrantha var. micranthared-root cryptantha KM
55BoragiCryptantha muricataprickly cryptantha1 
56BoragiCryptantha pterocarya var. cyclopteraTucson wing-nut cryptantha 10
57BoragiEmmenanthe penduliflora var. penduliflorawhispering bells220
58BoragiEucrypta chrysanthemifolia var. bipinnatifidaeucrypta18
59BoragiNama demissum var. demissumpurple mat215
60BoragiPectocarya platycarpabroad-fruited combseed KM
61BoragiPectocarya recurvatacurvenut combseed22
62BoragiPectocarya setosamoth combseed1 
63BoragiPhacelia distanscommon phacelia499
64BoragiPhacelia minorwild canterbury bells213
65BoragiPhacelia pedicellatapedicellate phacelia1 
66BoragiPholistoma membranaceumwhite fiesta flower499
67BrassiBoechera perennansperennial rock-cress^ 22
68BrassiBrassica tournefortii*Asian mustard 99
69BrassiCaulanthus cooperiCooper's jewel-flower22
70BrassiCaulanthus halliiHall's caulanthus 7
71BrassiCaulanthus lasiophyllusCalifornia mustard22
72BrassiDescurainia pinnataalkali western tansy-mustard 2
73BrassiLepidium lasiocarpum ssp. lasiocarpumhairy-podded pepper-grass^120
74BrassiLyrocarpa coulteriCoulter's lyrepod1 
75BrassiThysanocarpus curvipesfringe-pod27
76BrassiTropidocarpum gracileslender tropidocarpum KM
77CactacCylindropuntia bigeloviiteddy-bear cholla199
78CactacCylindropuntia californica var. parkericane cholla 2
79CactacCylindropuntia ganderiGander's cholla199
80CactacEchinocereus engelmanniiEngelmann's hedgehog cactus399
81CactacFerocactus cylindraceusCalifornia barrel cactus299
82CactacMammillaria dioicaCalifornia fish-hook cactus112
83CactacMammillaria tetrancistrafish-hook cactus13
84CactacOpuntia basilaris var. basilarisbeavertail cactus280
85CactacOpuntia engelmannii var. engelmanniiEngelmann prickly-pear 8
86CactacOpuntia phaeacanthadesert prickly-pear 15
87CampanNemacladus glanduliferusglandular nemacladus5 
88CampanNemacladus rubescensdesert nemacladus21
89CrassuCrassula connatapygmy-weed1 
90CrassuDudleya saxosa ssp. aloidesdesert dudleya144
91EuphorBernardia incanawestern bernardia^ 12
92EuphorChamaesyce melanadeniared-gland spurge 40
93EuphorChamaesyce micromeraSonoran spurge 99
94EuphorChamaesyce polycarpasmall-seeded spurge299
95EuphorChamaesyce setilobastarfish (Yuma) spurge225
96EuphorDitaxis lanceolatanarrowleaf ditaxis680
97EuphorDitaxis neomexicanaNew Mexico ditaxis199
98EuphorEuphorbia erianthabeetle spurge199
99EuphorStillingia linearifolialinear-leaved stillingia250
100FabaceAcmispon glaber var. brevialatusshort-winged deerweed^599
101FabaceAcmispon maritimus var. brevivexillusshort-bannered coastal lotus1 
102FabaceAcmispon rigidusdesert lotus 5
103FabaceAcmispon strigosusstrigose lotus499
104FabaceAstragalus palmeriPalmer's milk-vetch11
105FabaceDalea mollissimadowny dalea 2
106FabaceLupinus arizonicusArizona lupine1 
107FabaceLupinus concinnusbajada lupine 40
108FabaceLupinus sparsiflorusCoulter's lupine3 
109FabaceMarina parryiParry's marina799
110FabaceProsopis glandulosa var. torreyanahoney mesquite11
111FabacePsorothamnus schottiiindigo bush399
112FabacePsorothamnus spinosussmoke tree 10
113FabaceSenegalia greggiicatclaw 99
114FabaceSenna covesiiCoves's cassia236
115FouquiFouquieria splendens ssp. splendensocotillo 99
116GeraniErodium cicutarium*redstem filaree199
117GeraniErodium texanumTexas filaree 2
118KramerKrameria bicolorwhite rhatany 99
119KramerKrameria erectaPima rhatany1 
120LamiacHyptis emoryidesert-lavender399
121LamiacSalvia apianawhite sage399
122LamiacSalvia columbariaechia199
123LoasacMentzelia albicauliswhite-stemmed blazing star 3
124LoasacMentzelia veatchianaVeatch's blazing star1 
125LoasacPetalonyx thurberi ssp. thurberiThurber's sandpaper-plant1 
126MalvacAyenia compactaayenia115
127MalvacHibiscus denudatusrock hibiscus 3
128MalvacSphaeralcea ambigua var. ambiguaapricot mallow220
129MollugMollugo cerviana*carpet-weed 35
130MontiaCalyptridium monandrumsand cress130
131MontiaCalyptridium parryi var. arizonicumArizona sand cress^2 
132NyctagAllionia incarnatatrailing four o'clock 5
133NyctagBoerhavia coulteri var. palmeriCoulter's spiderling 99
134NyctagBoerhavia triquetra var. intermediafivewing spiderling 99
135NyctagMirabilis laevis var. retrorsaBigelow's desert four-o'clock250
136NyctagMirabilis laevis var. villosaBigelow's desert four-o'clock1 
137OleaceMenodora scabra var. glabrescensbroom twinberry1 
138OnagraCamissoniopsis ignotaJurupa Hills sun-cups^12
139OnagraCamissoniopsis pallida ssp. pallidapale sun-cup 50
140OnagraChylismia claviformis ssp. peirsoniibrown-eyed primrose21
141OnagraEulobus californicusCalifornia suncup199
142OrobanCastilleja foliolosawoolly Indian paintbrush1 
143PapaveEschscholzia minutiflora ssp. minutiflora^small-flowered poppy499
144PapaveEschscholzia parishiiParish's poppy2 
145PhrymaMimulus bigelovii var. bigeloviiBigelow's monkeyflower230
146PlantaAntirrhinum filipesdesert twining snapdragon1 
147PlantaMohavea confertifloraghost flower1 
148PolemoEriastrum eremicum ssp. eremicumdesert woolly-star399
149PolemoGilia stellatastar gilia113
150PolemoLangloisia setosissima ssp. setosissimabristly langloisia TGT
151PolemoLoeseliastrum schottiiSchott's calico TGT
152PolygoCentrostegia thurberired triangles1 
153PolygoChorizanthe brevicornu var. brevicornubrittle spineflower11
154PolygoChorizanthe fimbriata var. laciniatalace-fringed spineflower2 
155PolygoEriogonum davidsoniiDavidson's buckwheat 5
156PolygoEriogonum fasciculatum var. polifoliumCalifornia buckwheat199
157PolygoEriogonum inflatumdesert trumpet250
158PolygoEriogonum plumatellayucca buckwheat3 
159PolygoEriogonum thomasiiThomas' buckwheat1 
160PolygoEriogonum wrightii var. nodosumWright's buckwheat299
161PolygoPterostegia drymarioidesthreadstem 2
162RanuncDelphinium parishii ssp. subglobosumintermediate larkspur 20
163RhamnaZiziphus parryi var. parryilotebush15
164RosaceColeogyne ramosissimablack brush199
165RosacePrunus fremontiidesert apricot799
166RubiacGalium stellatumstar-flowered bedstraw499
167RutaceThamnosma montanaturpentine broom342
168SimmonSimmondsia chinensisjojoba190
169SolanaLycium andersoniiAnderson's desert-thorn150
170SolanaLycium cooperiCooper's box-thorn15
171SolanaNicotiana obtusifoliadesert tobacco 7
172SolanaPhysalis crassifoliathick-leaved ground cherry250
173UrticaParietaria hespera var. hesperapellitory140
174ViscacPhoradendron californicumdesert mistletoe140
175ZygophLarrea tridentatacreosote bush299
176AgavacAgave deserti var. desertidesert agave199
177AgavacYucca schidigeraMohave yucca199
178AlliacAllium fimbriatum var. fimbriatumfringed onion 1
179PoaceaAristida adscensionissix-weeks three-awn 1
180PoaceaAristida purpureapurple three-awn 40
181PoaceaBouteloua aristidoides var. aristidoidesneedle grama 1
182PoaceaBromus madritensis ssp. rubens*red brome 99
183PoaceaDasyochloa pulchellafluff grass1 
184PoaceaHilaria rigidabig galleta 18
185PoaceaMelica frutescenstall melica325
186PoaceaMuhlenbergia microspermalittleseed muhly 11
187PoaceaPoa secunda ssp. secundaone-sided bluegrass 20
188PoaceaSchismus barbatus*Mediterranean schismus 99
189PoaceaStipa parishii var. parishiiParish's needlegrass^ 20
190PoaceaStipa speciosadesert needlegrass230
191ThemidMuilla maritimamuilla 3

Voucher data provided by the participants of the Consortium of California Herbaria (

We thank Jim Roberts for his help with the survey on 21 December 2012, and Keir Morse for the additions from his photographs, and for his help with the part of the 28 December 2012 survey in Plum Canyon.

Go to:

Copyright © 2012-2013 by Larry Hendrickson, Tom Chester, James Dillane, Kate Harper and Adrienne Ballwey
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
Comments and feedback: Tom Chester
Updated 25 March 2013.