Flora of Extreme Northeast San Diego County
This checklist is a start at a flora of the portion of the Coachella Valley that is in Anza-Borrego Desert State Park in the extreme northeast corner of in San Diego County. It consists of a species list from voucher records kindly supplied by Jon Rebman from the San Diego Natural History Museum Herbarium, along with field observations on 21 January 2008. This is a subset of a checklist for the larger area of the southeast Santa Rosa Mountains.
The voucher records were all collected by Frank Gander, 79 specimens on 6 April 1937 and 3 specimens on 7 April 1937. The location of all these vouchers was given simply as extreme northeast corner of San Diego County, so their precise localities is unknown.
The survey on 21 January 2008 was done by the three authors with the help of Philip Erdelsky. The route we surveyed is shown in red on the following map:
The thick blue lines with arrows delineate the borders of San Diego County. The jagged blue lines highlight the 1000 foot and 3000 foot elevation contours.
This area contains no roads at all, and therefore it takes some effort to explore. There is no doubt that the vast majority of this area is completely unsurveyed botanically, and the following checklist is very incomplete.
The survey on 1/22/08 found 52 species. Of those 52 species, 33 were vouchered by Gander and 19 were not. (In this checklist, we assume that Gander's voucher determined as Opuntia acanthocarpa var. coloradensis is actually O. ganderi; see Opuntia ganderi In Extreme Northeast San Diego County).
The most abundant species not found by Gander are two non-native species that were introduced after 1937: Brassica tournefortii and what is probably Schismus sp. (there were no flowers yet on the plants at the time of our survey). The probable Schismus sp. is widespread on the flattish wash area. Brassica tournefortii has not yet become widespread here. We found only a few areas that had a heavy infestation, a wider area that had scattered plants, and fairly large areas with no specimens of this species.
Gander vouchered 82 taxa. Of those 82 taxa, our survey found 33 and missed 49. Nearly all of species we missed are annuals or perennials that we would not have been expected to see on our survey. About 11 taxa would have been seen if they were present, but nearly all of these taxa grow on the rocky slopes that we didn't explore.
The following gives a brief summary of the habitat covered on our 1/22/08 survey:
- 0.9 miles from the exact northeast corner of the county south to Travertine Palms Wash, just inside the county line. This area consists almost entirely of zillions of braided washes, with quite a large area of cryptobiotic crust found in patches between the active washes.
- 0.75 miles along the north-northwest-facing bottom of the ridge of the Santa Rosa Mountains extending toward the Salton Sea. There were occasional intact benches along the mountains, but the Travertine Palms Wash was mostly right up against the base of the steep slopes. Much of the hillsides consisted of recent sediment that was sparsely covered by plants.
- 0.15 miles into a west-flowing drainage cut into the steep slopes.
- A 0.7 mile loop around and on an old north-facing alluvial slope (bajada) which is being dissected by the current drainage system. Large areas of the slope are still intact, bounded by deeply-cut drainages on the east and west, and the alluvial slope itself is only very shallowly dissected.
One of the surprises from our survey is that this area on the northeastern rain-shadow side of the Santa Rosa Mountains is much wetter than the area on the other side! Essentially no annuals had germinated on the southern side of these mountains at the same longitude, but there were zillions of annuals in the area we surveyed.
This apparent contradiction is because the area on the south side of the Santa Rosa Mountains is in the rain shadow of the mountains to the west of the town of Borrego Springs. Hence it receives very little moisture from winter rain due to orographics (moisture being squeezed out of the atmosphere from elevation differences alone, without convection). But areas on the rain-shadow side that are immediately next to the high mountains do receive some spill-over rain from such storms.
This area is much more similar to the area immediately west of Borrego Springs than to anyplace on the south side of the SnRsMtns in this area.
Checklist for Southeast Santa Rosa Mountains
The Checklist is sorted first by category - dicots, monocots, and ferns - and then by family and scientific name. The Family and Scientific Name are from the Jepson Manual. An asterisk before the Common Name indicates a non-native taxon. A "~" before the Common and Scientific Names indicates a the determination that is likely, but is not 100%, usually because we have not yet seen flowers.
The two columns after the Common Name indicate whether a taxon was present in the 1/21/08 survey, and give a rough estimate of the number of plants and number of locations for each species in the entire survey. Maximum values are 99 plants, and 9 locations. The main intent of these columns are to indicate the species for which we found very few plants or locations.
The final column, Gander Voucher, indicates whether a Gander voucher exists.
# Family Scientific Name (*)Common Name 1/21/08 Survey Gander Voucher # Plants # Locations 1 Asclepiadaceae Sarcostemma hirtellum trailing townula X 2 Asteraceae Ambrosia dumosa burroweed 99 9 X 3 Asteraceae Bebbia juncea var. aspera sweetbush 50 9 X 4 Asteraceae Calycoseris wrightii white tackstem X 5 Asteraceae Chaenactis carphoclinia var. carphoclinia pebble pincushion X 6 Asteraceae Chaenactis fremontii Fremont pincushion X 7 Asteraceae Encelia farinosa brittlebush 99 9 X 8 Asteraceae Hymenoclea salsola var. salsola cheesebush 50 9 X 9 Asteraceae Monoptilon bellioides desert star X 10 Asteraceae Perityle emoryi Emory's rock-daisy 50 9 X 11 Asteraceae Peucephyllum schottii desert pine X 12 Asteraceae ~Rafinesquia neomexicana ~desert chicory 20 2 13 Asteraceae Senecio mohavensis Mojave ragwort X 14 Asteraceae Stephanomeria pauciflora var. pauciflora wire-lettuce 3 3 15 Asteraceae Trichoptilium incisum yellow-head X 16 Asteraceae Viguiera parishii Parish's viguiera X 17 Boraginaceae Amsinckia sp. fiddleneck 10 1 18 Boraginaceae Cryptantha barbigera bearded cryptantha X 19 Boraginaceae Cryptantha pterocarya var. cycloptera wing-nut cryptantha X 20 Boraginaceae Pectocarya recurvata curvenut combseed X 21 Brassicaceae Brassica tournefortii *Asian mustard 99 9 22 Brassicaceae Descurainia pinnata ssp. glabra smooth western tansy-mustard X 23 Brassicaceae Draba cuneifolia wedge-leaved draba X 24 Brassicaceae Lepidium lasiocarpum var. lasiocarpum hairy-podded pepper-grass X 25 Cactaceae Echinocereus engelmannii Engelmann's hedgehog cactus X 26 Cactaceae Ferocactus cylindraceus California barrel cactus 20 9 27 Cactaceae Mammillaria tetrancistra common fish-hook cactus 1 1 28 Cactaceae Opuntia basilaris var. basilaris beavertail cactus 3 3 X 29 Cactaceae Opuntia ganderi Gander's cholla 20 1 30 Cactaceae Opuntia ramosissima pencil cholla 10 5 31 Campanulaceae Nemacladus rubescens desert nemacladus X 32 Chenopodiaceae ~Chenopodium murale *~nettle-leaved goosefoot 1 1 33 Crassulaceae Crassula connata pygmy-weed 30 1 34 Cucurbitaceae Cucurbita palmata coyote melon X 35 Euphorbiaceae Chamaesyce polycarpa small-seeded spurge 30 9 X 36 Euphorbiaceae Ditaxis lanceolata narrowleaf ditaxis 20 9 X 37 Euphorbiaceae Euphorbia eriantha beetle spurge X 38 Fabaceae Acacia greggii catclaw 10 3 39 Fabaceae Astragalus nuttallianus var. cedrosensis Cedros milk-vetch X 40 Fabaceae Calliandra eriophylla fairyduster X 41 Fabaceae Cercidium floridum ssp. floridum blue palo verde 30 9 X 42 Fabaceae Dalea mollissima downy dalea X 43 Fabaceae Lotus salsuginosus var. brevivexillus short-bannered coastal lotus X 44 Fabaceae Lupinus arizonicus Arizona lupine X 45 Fabaceae ~Lupinus concinnus ~bajada lupine 1 1 46 Fabaceae Marina parryi Parry's marina X 47 Fabaceae Psorothamnus schottii indigo bush 10 3 X 48 Fabaceae Psorothamnus spinosus smoke tree 10 3 X 49 Fabaceae Senna covesii Coves's cassia X 50 Fouquieriaceae Fouquieria splendens ssp. splendens ocotillo 10 5 X 51 Hydrophyllaceae Emmenanthe penduliflora whispering bells X 52 Hydrophyllaceae Eucrypta micrantha desert eucrypta X 53 Hydrophyllaceae Phacelia crenulata var. ambigua heliotrope phacelia X 54 Hydrophyllaceae Phacelia distans common phacelia 99 9 X 55 Krameriaceae Krameria erecta Pima rhatany X 56 Krameriaceae Krameria grayi white rhatany 5 5 57 Lamiaceae Hyptis emoryi desert lavender 30 9 X 58 Lamiaceae ~Salvia columbariae ~chia 1 1 59 Lamiaceae Salvia vaseyi Vasey's sage X 60 Loasaceae Mentzelia desertorum desert blazing star X 61 Loasaceae Mentzelia involucrata bracted blazing star X 62 Malvaceae Eremalche rotundifolia desert five-spot 1 1 X 63 Malvaceae Hibiscus denudatus rock hibiscus 5 5 X 64 Malvaceae Horsfordia newberryi Newberry's velvet mallow 1 1 X 65 Malvaceae Sphaeralcea ambigua var. rosacea rosy apricot mallow X 66 Nyctaginaceae Allionia incarnata trailing four o'clock X 67 Nyctaginaceae Mirabilis bigelovii var. retrorsa wishbone plant 5 5 68 Nyctaginaceae Mirabilis californica California four o'clock X 69 Onagraceae Camissonia boothii ssp. condensata Booth's desert primrose 50 9 X 70 Onagraceae Camissonia californica California suncup 20 3 X 71 Onagraceae Camissonia chamaenerioides long-fruit suncup X 72 Onagraceae Camissonia claviformis brown-eyed primrose 99 9 X 73 Orobanchaceae Orobanche cooperi Cooper's broom-rape X 74 Papaveraceae Eschscholzia minutiflora small-flowered poppy X 75 Papaveraceae Eschscholzia parishii Parish's poppy X 76 Plantaginaceae Plantago ovata desert plantain X 77 Polemoniaceae Gilia latifolia broad-leaf gilia X 78 Polemoniaceae Gilia stellata star gilia X 79 Polemoniaceae Linanthus jonesii Jones' linanthus X 80 Polygonaceae Chorizanthe brevicornu var. brevicornu brittle spineflower X 81 Polygonaceae Chorizanthe rigida devil's spineflower 3 3 X 82 Polygonaceae Eriogonum inflatum desert trumpet 10 5 X 83 Polygonaceae Eriogonum thomasii Thomas' buckwheat X 84 Resedaceae Oligomeris linifolia narrowleaf oligomeris X 85 Scrophulariaceae Antirrhinum filipes desert twining snapdragon X 86 Scrophulariaceae Mohavea confertiflora ghost flower X 87 Solanaceae Lycium parishii Parish's desert-thorn 1 1 88 Solanaceae Physalis crassifolia thick-leaved ground cherry 2 2 X 89 Sterculiaceae Ayenia compacta ayenia X 90 Viscaceae Phoradendron californicum desert mistletoe 5 5 X 91 Zygophyllaceae Fagonia laevis California fagonia 1 1 92 Zygophyllaceae Fagonia pachyacantha sticky fagonia 40 9 X 93 Zygophyllaceae Larrea tridentata creosote bush 99 9 X 94 Poaceae Aristida adscensionis six-weeks three-awn X 95 Poaceae Erioneuron pulchellum fluff grass X 96 Poaceae Pleuraphis rigida big galleta 2 2 X 97 Poaceae ~Schismus sp. *~Mediterranean schismus 99 9 98 Poaceae Vulpia octoflora var. hirtella hairy six-weeks fescue X 99 Pteridaceae Cheilanthes parryi woolly lipfern X
Copyright © 2008 by Tom Chester, Wayne Armstrong, and Bill Sullivan
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Last update: 26 January 2008