Plant Guide to S. Trans Preserve Trail, Santa Rosa Plateau

This is a working list, about which I make no guarantees at all until I officially release it. Use at your own risk!

Introduction and Explanation of Plant Trail Guides

Highlights of This Trail
Fieldwork Dates and Summary of List Changes With Time
The Plant Guide
Comments On Specific Species


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. There were 90 trails in my 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
Total Taxa114100%

I found 1 additional species not in the above table, since it has not yet been fully identified. The unidentified ones are marked with ?, sp or ssp in the id? column in the guide, and have no entries in the #all column.

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 DateVisit ## taxa# "?"# "sp"# "~"# "ssp"

I didn't keep separate track of the changes on 5/15/03 and 12/8/03, but most of those changes came from 5/15/03. The drop in the number of taxa on 2/23/06 was due to combining the Calystegia macrostegia subspecies and dropping the "Phacelia ramosissima" seen on the trail only prior to 2005 and never fully verified.

I thank Kay Madore for her sharp eyes in helping me find interesting things on this trail on several of these trips.

The Plant Guide

Version for printing, without lines and other text on this page: html (5 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 rectified to be consistent with a GPS measurement of the trail length. Typical errors should be ~0.01 - 0.02 miles.

MileS#id?Common NameLatin Name#here#all
0.00   Beginning of guide at junction with Hidden Valley Road, heading south, toward the Vernal Pool Trail; elevation ~1885 feet (575 m).
0.00b1 *jointed goatgrassAegilops cylindrica20 / 14
0.00b2 *wild oatsAvena fatua99 / 926
0.00b3 *foxtail barleyHordeum murinum ssp. leporinum99 / 914
0.00b4 *Italian rye-grassLolium multiflorum99 / 918
0.00b5 *short-fruited filareeErodium brachycarpum99 / 914
0.00b6 *shortpod mustardHirschfeldia incana50 / 951
0.00b7 graceful tarplantHolocarpha virgata ssp. elongata99 / 915
0.00r8 vinegar weedTrichostema lanceolatum50 / 915
0.00b9 *ripgut bromeBromus diandrus / 52
0.00b10 *California burcloverMedicago polymorpha99 / 940
0.00b11 *soft chessBromus hordeaceus99 / 940
0.00r12 *little horseweedConyza bonariensis1 / 116
0.00r13 *sow thistleSonchus oleraceus2 / 242
0.00r  Sign: "Trans Preserve Trail (ahead and back); To Vernal Pools 1 mi; Hidden Valley Road (left-right)"
0.00r14 *windmill pinkSilene gallica / 33
0.00r15 dove weedEremocarpus setigerus99 / 925
0.00r16 dwarf lupineLupinus bicolor / 29
0.00b17 purple needlegrassNassella pulchra / 20
0.00r18 *hairy rattail fescueVulpia myuros var. hirsuta / 19
0.00b19 blue-eyed grassSisyrinchium bellum99 / 919
0.00b20 *smooth cat's earHypochaeris glabra / 35
0.00r21 *narrowleaf filagoFilago gallica / 45
0.00l22 purple sanicleSanicula bipinnatifida50 / 911
0.01l23 *prickly lettuceLactuca serriola2 / 242
0.02r24 pin-point cloverTrifolium gracilentum var. gracilentum / 8
0.02r25 *scarlet pimpernelAnagallis arvensis / 33
0.03r26 *mouse-ear chickweedCerastium glomeratum / 19
0.03r27 tawny popcorn flowerPlagiobothrys fulvus / 3
 r28 California filagoFilago californica / 21
0.06   Trail jags right.
0.06r29 checkerbloomSidalcea malviflora ssp. sparsifolia50 / 925
0.07r30 leafy daisyErigeron foliosus var. foliosus10 / 944
0.07r31 purple clarkiaClarkia purpurea ssp. quadrivulnera99 / 926
0.08b32 *red bromeBromus madritensis ssp. rubens / 53
0.08l  (San Diego wreathplant, Stephanomeria diegensis)
0.09   Trail bends right slightly
0.09l33 western buttercupRanunculus occidentalis50 / 96
0.09r34 sharp-toothed sanicleSanicula arguta10 / 516
0.10l35 Engelmann oakQuercus engelmannii10 / 923
0.10l36 southern miner's lettuceClaytonia perfoliata ssp. mexicana50 / 525
0.10   Trail bends left.
0.10l37 common bedstrawGalium aparine50 / 538
0.10l38 poison oakToxicodendron diversilobum99 / 943
0.10l  (wild-cucumber, Marah macrocarpus var. macrocarpus)
0.10l39 white-flowering currantRibes indecorum1 / 123
0.10r40 horseweedConyza canadensis / 38
0.10b41 fragrant everlastingGnaphalium canescens ssp. beneolens1 / 123
0.10l42 *horehoundMarrubium vulgare1 / 132
0.10l43 *hedge parsleyTorilis nodosa20 / 514
0.11r44 slender madiaMadia gracilis10 / 319
0.11b45 splendid mariposa lilyCalochortus splendens / 20
0.11   Trail begins to turn right 90°
0.11l46 coast live oakQuercus agrifolia var. agrifolia10 / 942
0.11r47 blue dicksDichelostemma capitatum ssp. capitatum50 / 946
0.11l48 *bull thistleCirsium vulgare+4 / 220
  49 big squirreltailElymus multisetus+ / 7
0.13b50 *winter vetchVicia villosa ssp. varia20 / 119
0.13   Local high point on trail; elevation 1960 feet (597 m)
0.13l51 wild-cucumberMarah macrocarpus var. macrocarpus / 44
0.13b52 *DarnelLolium temulentum40 / 94
0.13l53 California bromeBromus carinatus var. carinatus / 24
0.13   Trail bends left 90°
0.13l54sspmilk maidsCardamine californica var. californica10 / 26
0.13l55 climbing bedstrawGalium nuttallii ssp. nuttallii5 / 530
0.15l56 one-sided bluegrassPoa secunda ssp. secunda / 23
0.15l  Check for different clover.
0.15r57 *tocaloteCentaurea melitensis / 45
0.15l58 *cut-leaved geraniumGeranium dissectum20 / 213
0.15r59 *common groundselSenecio vulgaris10 / 118
 l  (blue larkspur, Delphinium parryi ssp. parryi)
0.15l60 warty spurgeEuphorbia spathulata10 / 14
0.15l61 Spanish cloverLotus purshianus var. purshianus20 / 231
0.16l62 grand mountain dandelionAgoseris grandiflora1 / 111
0.16l63 soap plantChlorogalum pomeridianum var. pomeridianum10 / 919
0.16   (Check for rusty-haired popcorn flower, Plagiobothrys nothofulvus.)
0.16l64 Indian milkweedAsclepias eriocarpa5 / 218
0.16r  (laurel sumac, Malosma laurina)
0.17   "Double trail" section, with the upper portion used when the lower portion is a mudpit
0.18l65 California-asterLessingia filaginifolia var. filaginifolia33 / 951
0.18l66 California everlastingGnaphalium californicum / 43
0.19l67 johnny jump-upViola pedunculata30 / 516
0.19r68 red maidsCalandrinia ciliata / 17
0.20b69 silver puffsUropappus lindleyi+ / 26
0.20b70 brown microserisStebbinsoseris heterocarpa / 3
0.20l71 fringe-podThysanocarpus curvipes50 / 49
0.21l72 slender cottonweedMicropus californicus var. californicus1 / 17
0.21l73 southern California morning-gloryCalystegia macrostegia ssp. arida+2 / 29
0.21l  (blue elderberry, Sambucus mexicana)
0.21 74 blue larkspurDelphinium parryi ssp. parryi5 / 314
0.21l  Bench with back
0.22l75 *rattail fescueVulpia myuros var. myuros / 20
0.22l  (chocolate lily, Fritillaria biflora var. biflora)
0.24l76 June grassKoeleria macrantha1 / 12
 l77 Douglas' microserisMicroseris douglasii ssp. douglasii / 1
0.26r78 chocolate lilyFritillaria biflora var. biflora+5 / 25
0.27r79 *prickly sow thistleSonchus asper ssp. asper1 / 130
0.27   Local low point on trail; elevation ~1925 feet (585 m); trail gradually turns left 90° and begins short steep uphill.
0.28b80 California poppyEschscholzia californica2 / 129
0.29l81 bajada lupineLupinus concinnus10 / 211
0.29l82 small-flowered fiddleneckAmsinckia menziesii var. menziesii10 / 18
0.30l83 Jepson's blue wildryeElymus glaucus ssp. jepsonii+1 / 112
0.31l84 *oliveOlea europaea1 / 110
0.32l  First of two good patches of milk maids, Cardamine californica
0.32b85 California sweet-cicelyOsmorhiza brachypoda10 / 26
0.32l86 blue wildryeElymus glaucus ssp. glaucus+5 / 221
0.32b87 goldenrodSolidago californica10 / 235
0.32b88 sticky cinquefoilPotentilla glandulosa ssp. glandulosa5 / 117
0.32r89 giant wild-ryeLeymus condensatus1 / 127
0.32l90 hollyleaf redberryRhamnus ilicifolia2 / 243
0.32   Trail turns right 90°
0.33b91 eucryptaEucrypta chrysanthemifolia var. chrysanthemifolia10 / 225
0.33l92 *hedge mustardSisymbrium officinale+30 / 920
0.33   Cross very small drainage.
0.33b93 hoary bowlesiaBowlesia incana30 / 13
0.33b94 blue elderberrySambucus mexicana2 / 148
0.33r95 *common chickweedStellaria media / 25
0.33l96 fiesta flowerPholistoma auritum var. auritum3 / 111
0.33l  Second good patch of milk maids, Cardamine californica
0.33l97 Pacific sanicleSanicula crassicaulis30 / 920
0.33l98 tree cloverTrifolium ciliolatum / 12
0.34b99 long-spurred plectritisPlectritis ciliosa ssp. insignis10 / 13
0.34 100 *wall bedstrawGalium parisiense / 7
0.34l101sptiny cloverTrifolium sp. /  
0.34l102 slender vetchVicia hassei+5 / 26
0.34r  Western buttercup, Ranunculus occidentalis, with 8-9 petals, in midst of sea of plants with 5 petals
0.34l  (woodland star, Lithophragma affine)
0.34b103 American vetchVicia americana var. americana1 / 18
0.34   Trail curves left with a short steep uphill, then right and a gentle uphill; begin long stretch of trail with no new taxa
0.39   Local high point; trail continues to mostly ascend gently
 b104 earth brodiaeaBrodiaea terrestris ssp. kernensis / 7
 r  (bush lupine, Lupinus excubitus var. hallii)
0.49   Trail jags left.
0.49l105 *white-stemmed filareeErodium moschatum / 20
0.49l106 California lotusLotus wrangelianus5 / 14
0.49l107 tomcat cloverTrifolium willdenovii / 17
0.49   (caterpillar phacelia, Phacelia cicutaria var. hispida)
0.49   Local high point; trail curves right.
0.49   Former field of fringe-pod in 1996-2001 is now a field of non-native grasses.
0.53l108 California bee plantScrophularia californica ssp. floribunda3 / 117
0.54l  (San Diego pea, Lathyrus vestitus var. alefeldii)
0.57l109 purple headAcourtia microcephala / 19
0.57r110 California fuchsiaEpilobium canum ssp. canum / 21
0.59   Trail bends right slightly
0.59l111 San Diego birdsfoot lotusLotus hamatus / 24
0.59l112 rattlesnake weedDaucus pusillus / 29
 l113 nodding needlegrassNassella cernua / 17
0.67r  (broom baccharis, Baccharis sarothroides)
0.68   Trail turns left 90°
0.70b114 San Diego wreathplantStephanomeria diegensis2 / 123
0.75r115 western ragweedAmbrosia psilostachya10 / 138
0.78   End trail at junction with Vernal Pool Trail; elevation 2060 feet (628 m)

Comments On Specific Species

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.

Cirsium vulgare. The plants found here in 2005 were weeded out.

Elymus multisetus, Uropappus lindleyi, Sisymbrium officinale and Koeleria macrantha. The location is uncertain for these taxa to within a few hundredths of a mile, so the order is not necessarily correct. The Elymus multisetus may have died in the 2001-2002 drought, since it has not been seen since then.

Fritillaria biflora var. biflora. There are many more plants off-trail, nearly all below the trail.

Elymus glaucus. Both subspecies appear to be present. The first specimen had a hairy sheath on 5/15/03, but two other plants sampled on different trips had glabrous sheaths.

Vicia hassei. The plants here were only single flowered, so could not be distinguished from V. ludoviciana. However, a short distance farther along the trail were plants with two widely-separated flowers, giving this id.

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Copyright © 2003-2006 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:
Comments and feedback: Tom Chester
Updated 4 March 2006.