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:

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.

#FamilyScientific Name(*)Common Name1/21/08 SurveyGander Voucher
# Plants# Locations
1AsclepiadaceaeSarcostemma hirtellumtrailing townula  X
2AsteraceaeAmbrosia dumosaburroweed999X
3AsteraceaeBebbia juncea var. asperasweetbush509X
4AsteraceaeCalycoseris wrightiiwhite tackstem  X
5AsteraceaeChaenactis carphoclinia var. carphocliniapebble pincushion  X
6AsteraceaeChaenactis fremontiiFremont pincushion  X
7AsteraceaeEncelia farinosabrittlebush999X
8AsteraceaeHymenoclea salsola var. salsolacheesebush509X
9AsteraceaeMonoptilon bellioidesdesert star  X
10AsteraceaePerityle emoryiEmory's rock-daisy509X
11AsteraceaePeucephyllum schottiidesert pine  X
12Asteraceae~Rafinesquia neomexicana~desert chicory202 
13AsteraceaeSenecio mohavensisMojave ragwort  X
14AsteraceaeStephanomeria pauciflora var. pauciflorawire-lettuce33 
15AsteraceaeTrichoptilium incisumyellow-head  X
16AsteraceaeViguiera parishiiParish's viguiera  X
17BoraginaceaeAmsinckia sp.fiddleneck101 
18BoraginaceaeCryptantha barbigerabearded cryptantha  X
19BoraginaceaeCryptantha pterocarya var. cyclopterawing-nut cryptantha  X
20BoraginaceaePectocarya recurvatacurvenut combseed  X
21BrassicaceaeBrassica tournefortii*Asian mustard999 
22BrassicaceaeDescurainia pinnata ssp. glabrasmooth western tansy-mustard  X
23BrassicaceaeDraba cuneifoliawedge-leaved draba  X
24BrassicaceaeLepidium lasiocarpum var. lasiocarpumhairy-podded pepper-grass  X
25CactaceaeEchinocereus engelmanniiEngelmann's hedgehog cactus  X
26CactaceaeFerocactus cylindraceusCalifornia barrel cactus209 
27CactaceaeMammillaria tetrancistracommon fish-hook cactus11 
28CactaceaeOpuntia basilaris var. basilarisbeavertail cactus33X
29CactaceaeOpuntia ganderiGander's cholla201 
30CactaceaeOpuntia ramosissimapencil cholla105 
31CampanulaceaeNemacladus rubescensdesert nemacladus  X
32Chenopodiaceae~Chenopodium murale*~nettle-leaved goosefoot11 
33CrassulaceaeCrassula connatapygmy-weed301 
34CucurbitaceaeCucurbita palmatacoyote melon  X
35EuphorbiaceaeChamaesyce polycarpasmall-seeded spurge309X
36EuphorbiaceaeDitaxis lanceolatanarrowleaf ditaxis209X
37EuphorbiaceaeEuphorbia erianthabeetle spurge  X
38FabaceaeAcacia greggiicatclaw103 
39FabaceaeAstragalus nuttallianus var. cedrosensisCedros milk-vetch  X
40FabaceaeCalliandra eriophyllafairyduster  X
41FabaceaeCercidium floridum ssp. floridumblue palo verde309X
42FabaceaeDalea mollissimadowny dalea  X
43FabaceaeLotus salsuginosus var. brevivexillusshort-bannered coastal lotus  X
44FabaceaeLupinus arizonicusArizona lupine  X
45Fabaceae~Lupinus concinnus~bajada lupine11 
46FabaceaeMarina parryiParry's marina  X
47FabaceaePsorothamnus schottiiindigo bush103X
48FabaceaePsorothamnus spinosussmoke tree103X
49FabaceaeSenna covesiiCoves's cassia  X
50FouquieriaceaeFouquieria splendens ssp. splendensocotillo105X
51HydrophyllaceaeEmmenanthe penduliflorawhispering bells  X
52HydrophyllaceaeEucrypta micranthadesert eucrypta  X
53HydrophyllaceaePhacelia crenulata var. ambiguaheliotrope phacelia  X
54HydrophyllaceaePhacelia distanscommon phacelia999X
55KrameriaceaeKrameria erectaPima rhatany  X
56KrameriaceaeKrameria grayiwhite rhatany55 
57LamiaceaeHyptis emoryidesert lavender309X
58Lamiaceae~Salvia columbariae~chia11 
59LamiaceaeSalvia vaseyiVasey's sage  X
60LoasaceaeMentzelia desertorumdesert blazing star  X
61LoasaceaeMentzelia involucratabracted blazing star  X
62MalvaceaeEremalche rotundifoliadesert five-spot11X
63MalvaceaeHibiscus denudatusrock hibiscus55X
64MalvaceaeHorsfordia newberryiNewberry's velvet mallow11X
65MalvaceaeSphaeralcea ambigua var. rosacearosy apricot mallow  X
66NyctaginaceaeAllionia incarnatatrailing four o'clock  X
67NyctaginaceaeMirabilis bigelovii var. retrorsawishbone plant55 
68NyctaginaceaeMirabilis californicaCalifornia four o'clock  X
69OnagraceaeCamissonia boothii ssp. condensataBooth's desert primrose509X
70OnagraceaeCamissonia californicaCalifornia suncup203X
71OnagraceaeCamissonia chamaenerioideslong-fruit suncup  X
72OnagraceaeCamissonia claviformisbrown-eyed primrose999X
73OrobanchaceaeOrobanche cooperiCooper's broom-rape  X
74PapaveraceaeEschscholzia minutiflorasmall-flowered poppy  X
75PapaveraceaeEschscholzia parishiiParish's poppy  X
76PlantaginaceaePlantago ovatadesert plantain  X
77PolemoniaceaeGilia latifoliabroad-leaf gilia  X
78PolemoniaceaeGilia stellatastar gilia  X
79PolemoniaceaeLinanthus jonesiiJones' linanthus  X
80PolygonaceaeChorizanthe brevicornu var. brevicornubrittle spineflower  X
81PolygonaceaeChorizanthe rigidadevil's spineflower33X
82PolygonaceaeEriogonum inflatumdesert trumpet105X
83PolygonaceaeEriogonum thomasiiThomas' buckwheat  X
84ResedaceaeOligomeris linifolianarrowleaf oligomeris  X
85ScrophulariaceaeAntirrhinum filipesdesert twining snapdragon  X
86ScrophulariaceaeMohavea confertifloraghost flower  X
87SolanaceaeLycium parishiiParish's desert-thorn11 
88SolanaceaePhysalis crassifoliathick-leaved ground cherry22X
89SterculiaceaeAyenia compactaayenia  X
90ViscaceaePhoradendron californicumdesert mistletoe55X
91ZygophyllaceaeFagonia laevisCalifornia fagonia11 
92ZygophyllaceaeFagonia pachyacanthasticky fagonia409X
93ZygophyllaceaeLarrea tridentatacreosote bush999X
94PoaceaeAristida adscensionissix-weeks three-awn  X
95PoaceaeErioneuron pulchellumfluff grass  X
96PoaceaePleuraphis rigidabig galleta22X
97Poaceae~Schismus sp.*~Mediterranean schismus999 
98PoaceaeVulpia octoflora var. hirtellahairy six-weeks fescue  X
99PteridaceaeCheilanthes parryiwoolly lipfern  X

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Copyright © 2008 by Tom Chester, Wayne Armstrong, and Bill Sullivan
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
Last update: 26 January 2008