Plant Guide to N. Los Santos Trail / N. Hidden Valley Road Loop, Santa Rosa Plateau

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

This trail is incomplete for annuals only noticeable in the spring since it has been covered only in the fall and summer, and in March 2006 during a drought.

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


This is a loop hike beginning and ending at the Hidden Valley Parking Lot. It begins on the signed Hidden Valley Road heading south from the Parking Lot, traverses the entire North Los Santos Trail and then returns via Hidden Valley Road.

This trip is a nice hike, with expansive views over the grasslands and oak woodlands of the Santa Rosa Plateau, as well as views to San Gorgonio, San Jacinto, Santa Rosa, Palomar and Cuyamaca Mountains.

This loop hike is 2.20 miles round-trip, with 250 feet of elevation gain and loss.

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 our database that contain each taxon on this trail. There were 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 our 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

We found 3 additional species not in the above table, since they have not been fully identified yet. 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"

In addition, plants near mile 1.29 were checked on 3/16/06 and 4/13/05, which resulted in the identification of Sanicula bipinnata there.

The Plant Guide

Version for printing, without lines and other text on this page (6 pages)

The mileages have been adjusted to a GPS measurement of the entire route, and should be accurate to 0.01-0.02 miles.

Miles#id?Common NameLatin Name#here#all
0.00   Begin guide just before gate at Hidden Valley Trailhead, heading south on Hidden Valley Road; elevation ~1875 feet (570 m)
0.00b1 *short-fruited filareeErodium brachycarpum99 / 915
0.00b2 *foxtail barleyHordeum murinum ssp. glaucum30 / 414
0.00b3 *smooth cat's earHypochaeris glabra99 / 935
0.00b4 *shortpod mustardHirschfeldia incana99 / 951
0.00l5 purple needlegrassNassella pulchra99 / 920
0.00b6 *narrowleaf filagoFilago gallica99 / 945
0.00b7 *soft chessBromus hordeaceus99 / 940
0.00l8 Spanish cloverLotus purshianus var. purshianus99 / 931
0.00b9 *red bromeBromus madritensis ssp. rubens50 / 953
0.00b10 *redstem filareeErodium cicutarium99 / 955
0.00b11 *California burcloverMedicago polymorpha99 / 940
0.00l12 horseweedConyza canadensis50 / 936
0.00b13 *Italian rye-grassLolium multiflorum99 / 918
0.00b14 *nit grassGastridium ventricosum99 / 925
0.00   Go through entrance on left of gate across road
0.00l15 graceful tarplantHolocarpha virgata ssp. elongata99 / 914
0.00l16 *slender wild oatsAvena barbata99 / 940
0.00b17 *sand spurreySpergularia bocconei20 / 414
0.00l  Sign: "No mountain bikes; no horseback riding".
0.00l18 *jointed goatgrassAegilops cylindrica99 / 94
0.00r19 dove weedEremocarpus setigerus99 / 924
0.00b20 *wild oatsAvena fatua99 / 926
0.00r21 checkerbloomSidalcea malviflora ssp. sparsifolia99 / 925
0.00r22 dwarf lupineLupinus bicolor99 / 929
0.00r23sppopcorn flowerPlagiobothrys sp. /  
0.00l  Sign: "Coyote Trail (left), 0.5 mi to Trans Preserve Trail; Hidden Valley Road (straight) to Los Santos Trail; ["0.6 mi" crossed-out]
0.00l  Sign: "Mountain Lion ..."
0.00r24 *hairy rattail fescueVulpia myuros var. hirsuta99 / 919
0.01r25 *sow thistleSonchus oleraceus40 / 942
0.02r26 *spring vetchVicia sativa ssp. sativa99 / 96
0.02r27 purple clarkiaClarkia purpurea ssp. quadrivulnera99 / 926
0.02r28 vinegar weedTrichostema lanceolatum50 / 914
0.02r29 *windmill pinkSilene gallica20 / 233
0.02r30 *ripgut bromeBromus diandrus20 / 252
0.02r31 johnny jump-upViola pedunculata50 / 916
0.05r32 southern California morning-gloryCalystegia macrostegia ssp. arida+30 / 97
0.06r33 Indian milkweedAsclepias eriocarpa50 / 918
0.09r34splike bishop's lotusLotus sp. /  
0.10r35 California-asterLessingia filaginifolia var. filaginifolia15 / 551
0.11r36 Palmer's goldenbushEricameria palmeri var. pachylepis20 / 310
0.12r  (prickly lettuce, Lactuca serriola)
0.12r37 sharp-toothed sanicleSanicula arguta3 / 316
0.13l38 *scarlet pimpernelAnagallis arvensis50 / 933
0.14l39 *prickly sow thistleSonchus asper ssp. asper3 / 230
0.15r40 California poppyEschscholzia californica1 / 129
0.16   Local high point on road; elevation ~1925 feet (587 m); good view of San Gorgonio, San Jacinto, Santa Rosa, Palomar and Cuyamaca Mountains
0.16l  (Engelmann oak, Quercus engelmannii)
0.18c41 *knotweedPolygonum arenastrum10 / 519
0.19l42 *Bermuda grassCynodon dactylon30 / 931
0.19r  (wrinkled rush, Juncus rugulosus)
0.19r43 *curly dockRumex crispus10 / 923
0.20l44 shooting starDodecatheon clevelandii ssp. clevelandii30 / 311
0.20r  Jct. Los Santos Trail; go right on it; Sign: "Los Santos Trail (ahead), to Vernal Pool 2.3 mi; to Hidden Valley Trailhead (right)"
0.22   Local high point on trail
0.22r45 elk thistleCirsium scariosum50 / 911
0.24r  (coast live oak, Quercus agrifolia var. agrifolia)
0.26   Cross line of old fenceposts
0.30r46 toad rushJuncus bufonius var. bufonius / 14
0.30   Local low point on trail; elevation ~1915 feet (584 m)
0.31l47 California fuchsiaEpilobium canum ssp. canum10 / 421
0.31   Minor local high point on trail
0.32   Minor local low point on trail
0.35l48 big squirreltailElymus multisetus2 / 18
0.36   Local high point on trail
0.39   Minor local low point on trail
0.40l  (California everlasting, Gnaphalium californicum)
0.41   Begin long switchback left
0.42l49 fragrant everlastingGnaphalium canescens ssp. beneolens30 / 923
0.42   Trail begins many S-curves / switchbacks heading uphill; some have been cut by use trails, blocked off in 2006 by "Trail Closed" signs
0.49r50 long-stemmed buckwheatEriogonum elongatum var. elongatum2 / 128
0.49r51 rattlesnake weedDaucus pusillus2 / 129
0.50b52 bush lupineLupinus excubitus var. hallii5 / 110
0.50l  (telegraph weed, Heterotheca grandiflora)
0.55r53 California four o'clockMirabilis californica1 / 123
0.56r54 white everlastingGnaphalium canescens ssp. microcephalum5 / 336
0.56r  (poison oak, Toxicodendron diversilobum)
0.57l  ("Meteor Crater"; perhaps a blow-out due to drainage from a former spring?)
0.61r55 *prickly lettuceLactuca serriola99 / 942
0.61l  Switchback left.
0.62r56 blue dicksDichelostemma capitatum ssp. capitatum99 / 946
0.66   Trail curves right 90°
0.71r57 California everlastingGnaphalium californicum10 / 343
0.73r  (goldenrod, Solidago californica)
0.73r58 coast-range melicMelica imperfecta5 / 243
0.75r59 *tocaloteCentaurea melitensis10 / 445
0.76r60 common bedstrawGalium aparine99 / 940
0.76l  (blue elderberry, Sambucus mexicana)
0.77b61 coast live oakQuercus agrifolia var. agrifolia5 / 142
0.77b62 southern miner's lettuceClaytonia perfoliata ssp. mexicana99 / 325
0.77r  Jct. path to ridge crest
0.77r63 *rose cloverTrifolium hirtum20 / 413
0.77l  (narrowleaf bedstraw, Galium angustifolium ssp. angustifolium)
0.77l  (leafy daisy, Erigeron foliosus var. foliosus)
0.79l  View of 200 inch telescope on Palomar Mountain; North Peak now visible north of Cuyamaca Peak
0.84r  (laurel sumac, Malosma laurina; white-flowering currant, Ribes indecorum)
0.86   Local high point on trail, with great views; elevation ~2070 feet (630 m)
0.86b64 Engelmann oakQuercus engelmannii5 / 323
0.87r  (in distance: California buckwheat, Eriogonum fasciculatum var. foliolosum; white sage, Salvia apiana)
0.88   Local low point on trail
0.91   Local high point on trail
0.98   Local low point on trail
0.99r65 western ragweedAmbrosia psilostachya50 / 537
1.00l  Jct. alternate trail, a leftover trail from when the Los Santos Trail was not complete; stay right
1.00r  Walter B. Gerken bench, with great views from it; local high point
1.06r  (Basalt rocks)
1.07b66 rattlesnake weedChamaesyce albomarginata5 / 110
1.08r  (Vasey's prickly-pear, Opuntia vaseyi)
1.11l  Trail turns left 45°
1.17l  Jct. other end of alternate trail; continue straight
1.18   Trail crosses small saddle
1.19l67 San Diego birdsfoot lotusLotus hamatus20 / 224
1.20l68 *gazaniaGazania X (mounding hybrid)+1 / 16
1.22r  (western sycamore, Platanus racemosa; big leaf mistletoe, Phoradendron macrophyllum)
1.25r69 western vervainVerbena lasiostachys var. lasiostachys20 / 210
1.25   Begin bridge over branch of Cole Creek; elevation ~1950 feet (594 m)
1.25l70 California sagebrushArtemisia californica1 / 147
1.25l71 *winter vetchVicia villosa ssp. varia99 / 519
1.25l72 wrinkled rushJuncus rugulosus10 / 212
1.25l73 *rabbits-foot grassPolypogon monspeliensis10 / 223
1.25l74 *Italian thistleCarduus pycnocephalus20 / 321
1.25b75 umbrella sedgeCyperus eragrostis5 / 111
1.25b76 *grass polyLythrum hyssopifolia5 / 115
1.25l77 spike primroseEpilobium densiflorum10 / 25
1.25l78 common spikerushEleocharis macrostachya10 / 112
1.25l  (deergrass, Muhlenbergia rigens; cocklebur, Xanthium strumarium; common cudweed, Gnaphalium luteo-album)
1.26   End bridge
1.29l  (California coffeeberry, Rhamnus californica ssp. californica; fiesta flower, Pholistoma auritum var. auritum; poison sanicle, Sanicula bipinnata ; pistachio, Pistacia atlantica)
1.30l79 western sycamorePlatanus racemosa2 / 227
1.34l80 deergrassMuhlenbergia rigens5 / 221
1.38r  Jct. S. Los Santos Trail; elevation ~1910 feet (582 m), local low point on trail; continue straigh
1.48   Begin short steep uphill
1.52l  Jct. Hidden Valley Road; go left on it; elevation 1920 feet (585 m); sign facing that section of road: "Los Santos Trail (to right); To Adobes 1.5 mi (to left)"
1.62   Road curves left 90°
1.65r81 *annual blue grassPoa annua30 / 313
1.74r82~saltgrassDistichlis spicata20 / 416
1.74r83 *cut-leaved geraniumGeranium dissectum30 / 213
1.75b84 clustered field sedgeCarex praegracilis50 / 17
1.75l85 *common cudweedGnaphalium luteo-album3 / 216
1.75r86 *tumble pigweedAmaranthus albus20 / 213
1.78r87 creeping wild ryeLeymus triticoides5 / 211
1.79b88 *pineapple weedChamomilla suaveolens30 / 120
1.80   Road jogs left
1.81l89 *hedge mustardSisymbrium officinale5 / 122
1.81l90 red maidsCalandrinia ciliata20 / 118
1.81r91 cockleburXanthium strumarium5 / 116
1.81c92 small-flowered nightshadeSolanum americanum5 / 13
1.81c93 willow-leaved dockRumex salicifolius var. denticulatus3 / 18
1.81r94 common fiddleneckAmsinckia menziesii var. intermedia5 / 216
1.81b95 Mexican rushJuncus mexicanus20 / 116
1.81r96 Hooker's evening-primroseOenothera elata ssp. hirsutissima5 / 110
1.81r  (common monkeyflower, Mimulus guttatus)
1.82r97 arroyo willowSalix lasiolepis1 / 135
1.82b sp(cattail, Typha sp.)
1.82l  (rigid hedge-nettle, Stachys ajugoides var. rigida)
1.82   Cross same branch of Cole Creek again; local low point on road; elevation ~1900 feet (580 m)
1.82r  (red willow, Salix laevigata)
1.86r98 telegraph weedHeterotheca grandiflora2 / 235
1.99   Local high point on road; elevation 1920 feet (585 m)
2.00l  Jct. N. Los Santos Trail; end guide
2.20   Back at Trailhead; elevation ~1875 feet (570 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 Tom 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 Tom found clear evidence that subspecies "intermedia" and "tenuifolia" are bogus. Hence we assign all the SRP plants to ssp. arida.

Gazania X (mounding hybrid). A single plant was found on 12/18/04, and it was eradicated.

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Copyright © 2004-2006 by Tom Chester and Kay Madore
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 11 March 2006.