Laguna Mountains: Plant Guide to Volcan Mountain Loop

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

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


Volcan Mountain is an elongate fault-slice block with a northwest to southeast length of about 12 miles and a width of about 4 miles. It covers somewhere between 25,000 and 30,000 acres. It ranges in elevation from about 3000 feet on its west (Santa Ysabel Valley), north (Lake Henshaw / San Jose Valley) and east ends (San Felipe Valley) and about 4000 feet on its south end at Julian, to its ridgeline having elevations of 4700 to 6140 feet.

Geologically, Volcan Mountain similar to the neighboring Palomar Mountains to the northwest. The northwest end of Volcan Mountain is just five miles, across the Lake Henshaw Valley, from the southeast end of the Palomar Mountains. High Point on Palomar, at 6140 feet elevation, is 18.6 miles from Pechacho, the highest peak on Volcan, at 5719 feet elevation.

Floristically, however, Volcan Mountain is probably more similar to the Cuyamaca Mountains, both being ~40 miles from the coast and closer to the desert, compared to the Palomar Mountains ~30 miles from the coast. North Peak, at 5993 feet elevation, is just 6.5 miles from Volcan, the southernmost peak on Volcan with an elevation of 5353 feet. Frank Gander included Volcan Mountain in his Floristic Area #10, which also includes Julian, the Cuyamaca and Laguna Mountains.

However, until recently, very little botanical work has been done at Volcan since it has been privately owned and closed to the public for over a century. Most of the northern part of the Mountain, about 8,000 acres, is part of the 15,500 acre Santa Ysabel Indian Reservation and is not open to the public. Most of the southernmost part of the mountain was the 11,000 acre Rutherford Ranch.

Volcan has become increasingly opened to the public thanks to the preservation efforts of Julian residents after development was proposed for the west face of Volcan in 1988. The Volcan Mountain Preserve Foundation, with the goal of preserving the entire Mountain, was the direct result of this community action. The impressive trailhead Hubbell Gateway was also a community effort, designed by the famous artist and sculptor James Hubbell, who also directed its construction by local volunteers.

In 1989 San Diego County purchased 200 acres for a wilderness park. Subsequent land purchases have increased the total preserved acreage to over 16,800 acres, with the Volcan Mountain Preserve Foundation accounting for 4,754 acres of that total (see link for more information about Volcan Mountain).

Public access to Volcan Mountain is available at two San Diego County Parks: the 2,400 acre Volcan Mountain Wilderness Preserve, with 3.7 miles of trails open to the public, and the 3,800 acre Santa Ysabel Open Space Preserve, with 11 miles of trails. San Dieguito River Park, California Department of Fish and Game, California Division of Forestry and the Bureau of Land Management administer other portions of the acreage on the north and east sides of Volcan Mountain.

See map showing part of the Volcan Mountain Open Space Preserve, along with its fire history.

Botanical work has been done on both county parks. Fred Sproul compiled a checklist of flora for the Volcan Mountain Wilderness Preserve in 2000, from his fieldwork in June and August 2000 and species observed by a few other botanists on separate trips. Virginia Moran did extensive Rare Plants and Vegetation Surveys in 2002-2003 for the Santa Ysabel Open Space Preserve.

This plant trail guide covers a 5.0 mile loop of all the public trails of Volcan Mountain, which includes the 2.1 mile main access road show in dark blue on the map below, and the 1.6 mile Five Oaks Trail, opened to the public in 2004, shown in green. The total elevation gain and loss is about 1300 feet, with about 100 feet of up and down in addition to the 1193 feet gain from the 4160 feet elevation of the Hubbell Gateway to the 5353 feet elevation of Volcan peak. The guide takes the trail on the way up, and the road on the way down. However, note that the road is a steep former Jeep road, and some people may find it unpleasant to descend it. If you aren't interested in seeing the species found only on the section of road on the way down, you may wish to take the trail on the way down as well.

Directions to trailhead: from the town of Santa Ysabel on SR79, turn left onto Wynola Road at Wynola, just past the former Tom's Chicken Shack, soon to be a Hungarian Restaurant. The scenic Wynola Road bends and climbs along Jim Green Creek and its canyon, called Juch canyon, which is covered in beautiful flowers in the spring. Note especially the wonderful display of fairy lanterns, Calochortus albus, paintbrush, and strawberries. Continue past Farmer Road on the right at mile 3.3, and turn left on Farmer Road on the left at mile 3.4. The Preserve entrance is on the right 0.1 miles north on Farmer Road. The Volcan Mountain Preserve is signed at its entrance on Farmer Road 0.1 miles north of Wynola Road; park along Farmer Road.

From Julian, take Farmer Road north to its T-junction with Wynola Road, then jog right on Wynola Road to the continuation of Farmer Road and the Preserve entrance.

Highlights of This Trail

Some of the botanical highlights of this trail are:

Species found only on this trail, out of my 103 trails from all of southern California, or at most one other trail, are in the following table:

# TrailsScientific Name
1*Cynosurus echinatus
1Gilia sinuata
1Hymenothrix wrightii
1*Malus sylvestris
1Mentzelia veatchiana
1Salvia apiana X S. clevelandii (S. X palmeri)
1Symphoricarpos albus var. laevigatus
1Vulpia microstachys var. confusa
2Allophyllum gilioides ssp. violaceum
2Athysanus pusillus
2Camissonia confusa
2*Cnicus benedictus
2Collinsia childii
2Elymus trachycaulus
2Githopsis diffusa ssp. candida
2Orobanche fasciculata
2Penstemon heterophyllus var. heterophyllus
2Phlox gracilis
2Plantago patagonica
2Platystemon californicus
2Polystichum imbricans ssp. curtum
2*Sanguisorba minor ssp. muricata

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 103 trails in my database when this histogram was made; of those trails, this is the only one in the Volcan Mountains. A number of "1" means the taxon has only been found on this trail among the trails in my database.

Number of Trails
Containing A Taxon
Number Of Taxa
On This Trail
% of Taxa
On This Trail
Total Taxa191100%

I found 4 additional species not in the above table, since they have not been identified yet. The unidentified ones are marked with ? or sp in the id? column in the guide, and do not have any number given 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 thank Kate Shapiro for alerting me to the excellent spring bloom on Volcan Mountain in the severe drought year of 2007, and for sharing her knowledge of local flora and the Volcan trail in valuable field assistance on 5/16/07 and 5/20/07. Kate also added the Penstemon heterophyllus from fieldwork on 5/30/07.

I thank Kay Madore, Wayne Armstrong and a person who wishes to remain anonymous for assistance with the fieldwork on 5/20/07.

I thank Jeri Hirshberg for supplying the correct determination for the Erigeron divergens on 6/3/07 that I had misidentified, which led to the discovery of the interesting information on that taxon given below.

Botanical Trip Reports

The Plant Guide

Version for printing, without lines and other text on this page: html (9 pages) or pdf Clickbook booklet (3 double-sided pages). (See printing instructions for an explanation of these options)

MileS#id?Common NameLatin Name#here#all
0.00   Begin trail at Hubbell Gateway; elevation 4160 feet (1268 m)
0.00b1 *foxtail barleyHordeum murinum50 / 324
0.00b2 California bromeBromus carinatus var. carinatus50 / 927
0.00b3 *ripgut bromeBromus diandrus99 / 955
0.00b4 *English plantainPlantago lanceolata99 / 921
0.00b5 *redstem filareeErodium cicutarium99 / 962
0.00b6 *pineapple weedChamomilla suaveolens99 / 523
0.00b7 *downy bromeBromus tectorum99 / 927
0.00b8 *knotweedPolygonum arenastrum30 / 522
0.00b9 *California burcloverMedicago polymorpha10 / 243
0.00b10 California-asterLessingia filaginifolia var. filaginifolia99 / 957
0.00b11 *soft chessBromus hordeaceus99 / 942
0.00b12 common fiddleneckAmsinckia menziesii var. intermedia+10 / 320
0.00b13 *slender wild oatsAvena barbata99 / 942
0.00r14 western redbudCercis occidentalis+1 / 15
0.00l15 California black oakQuercus kelloggii+30 / 914
0.00r16 angel's giliaGilia angelensis99 / 915
0.00r17 dwarf lupineLupinus bicolor99 / 931
0.00r18 purple clarkiaClarkia purpurea ssp. quadrivulnera99 / 927
0.00r  (leafy daisy, Erigeron foliosus var. foliosus; splendid mariposa lily, Calochortus splendens; blue dicks, Dichelostemma capitatum ssp. capitatum; popcorn flower, Cryptantha intermedia)
0.00r19 Indian cloverTrifolium albopurpureum var. albopurpureum99 / 94
0.00l  Display Board
0.00b20 California buckwheatEriogonum fasciculatum var. polifolium+50 / 926
0.00b21 *wild oatsAvena fatua20 / 529
0.00l22 *smooth cat's earHypochaeris glabra50 / 938
0.00r  (matchweed, Gutierrezia sarothrae)
0.00b23 spreading fleabaneErigeron divergens+99 / 948
0.00r24 *blessed thistleCnicus benedictus5 / 32
0.00r  (Spanish clover, Lotus purshianus var. purshianus; flax-flowered linanthus, Linanthus liniflorus)
0.00r25 narrowleaf bedstrawGalium angustifolium ssp. angustifolium10 / 953
0.00r26 western ragweedAmbrosia psilostachya50 / 942
0.00b27 rusty-haired popcorn flowerPlagiobothrys nothofulvus10 / 115
0.00b28 *shortpod mustardHirschfeldia incana30 / 954
0.00r  (bush lupine, Lupinus excubitus var. hallii)
0.00r  Sign: "Entering mountain lion country..."
0.01l29 hoary coffeeberryRhamnus tomentella ssp. tomentella20 / 93
0.01l30 *domestic appleMalus sylvestris1 / 11
0.01r31 Mexican manzanitaArctostaphylos pungens30 / 95
0.02r32 California bee plantScrophularia californica ssp. floribunda20 / 521
0.02l33 white sageSalvia apiana40 / 943
0.02b34 popcorn flowerCryptantha intermedia30 / 929
0.02l35 imbricate phaceliaPhacelia imbricata ssp. patula30 / 99
0.02l36 *horehoundMarrubium vulgare1 / 136
0.02l37 *red bromeBromus madritensis ssp. rubens50 / 962
0.02r38 arroyo willowSalix lasiolepis2 / 142
0.02l39 fragrant everlastingGnaphalium canescens ssp. beneolens10 / 927
0.02r40 blue dicksDichelostemma capitatum ssp. capitatum40 / 949
0.03r41 blue elderberrySambucus mexicana10 / 953
0.03r42 Spanish cloverLotus purshianus var. purshianus10 / 233
0.03r43 tomcat cloverTrifolium willdenovii99 / 918
0.03r44 *narrowleaf filagoFilago gallica20 / 346
0.04r45 fringed spineflowerChorizanthe fimbriata var. fimbriata10 / 19
0.04r  Sign: "Wildfire..."
0.04r46 Patagonia plantainPlantago patagonica30 / 32
0.04r47 canyon live oakQuercus chrysolepis40 / 927
0.05r48 willow-leaved dockRumex salicifolius var. denticulatus2 / 210
0.05l49 flax-flowered linanthusLinanthus liniflorus20 / 13
0.06b50 bush lupineLupinus excubitus var. hallii10 / 211
0.06l51 matchweedGutierrezia sarothrae3 / 117
0.06l52 shining peppergrassLepidium nitidum var. nitidum20 / 28
0.06l53 small-head field cloverTrifolium microcephalum10 / 211
0.06l54 tree cloverTrifolium ciliolatum30 / 913
0.06l55 purple owl's-cloverCastilleja exserta ssp. exserta50 / 914
0.06l56 silver puffsUropappus lindleyi40 / 929
0.06l57 globe giliaGilia capitata ssp. abrotanifolia99 / 98
0.06l58 *windmill pinkSilene gallica40 / 935
0.06l59 *hairy rattail fescueVulpia myuros var. hirsuta99 / 921
0.06l60 common linanthusLinanthus parviflorus99 / 99
0.07l61 bristly bird's beakCordylanthus rigidus ssp. setigerus10 / 134
0.07l62 clustered broom-rapeOrobanche fasciculata20 / 32
0.07l  (scarlet bugler, Penstemon centranthifolius)
0.07l63 *winter vetchVicia villosa ssp. varia10 / 221
0.08r64 gray sageSalvia apiana X S. clevelandii (S. X palmeri)1 / 11
0.08r65 scarlet buglerPenstemon centranthifolius10 / 312
0.09r  (yarrow, Achillea millefolium)
0.10r66 strigose lotusLotus strigosus50 / 938
0.12r67~sapphire woolly-starEriastrum sapphirinum20 / 19
0.14b68spannual buckwheat (round leaf)Eriogonum sp.10 / 9 
0.14b69 San Bernardino sun-cupCamissonia confusa30 / 92
0.14r70~Wright's thimbleheadHymenothrix wrightii20 / 11
0.15r71~twiggy wreath plantStephanomeria virgata ssp. pleurocarpa10 / 52
0.15r72 bristly goldenasterHeterotheca sessiliflora ssp. echioides2 / 19
0.17r73 Coulter's snapdragonAntirrhinum coulterianum30 / 47
0.17l74 leafy daisyErigeron foliosus var. foliosus20 / 948
0.20r75 California fuchsiaEpilobium canum+5 / 118
0.20b76 splendid mariposa lilyCalochortus splendens10 / 321
0.20r77 *garden burnetSanguisorba minor ssp. muricata5 / 12
0.20r78~southern mule's earsWyethia ovata3 / 25
0.21r79 checkerbloomSidalcea malviflora ssp. sparsifolia40 / 926
0.23r  (June grass, Koeleria macrantha; incense-cedar, Calocedrus decurrens)
0.26r80 bajada lupineLupinus concinnus20 / 912
0.26r81 slender cottonweedMicropus californicus var. californicus10 / 38
0.26r82 Wright's buckwheatEriogonum wrightii var. membranaceum40 / 96
0.27r83 June grassKoeleria macrantha5 / 23
0.27r  California black oakQuercus kelloggii+ /  
0.28r  Check for Calochortus weedii
0.28l  Jct. use path to grinding stones
0.30r84 wild-cucumberMarah macrocarpus var. macrocarpus2 / 247
0.31l  (oak mistletoe, Phoradendron villosum)
0.31l  Check for eucrypta
0.31l85 volcanic giliaGilia ochroleuca ssp. exilis30 / 43
0.31b86 baby blue eyesNemophila menziesii var. menziesii99 / 99
0.31l87 annual phloxPhlox gracilis30 / 42
0.33r88 narrow-leaved miner's lettuceClaytonia parviflora ssp. parviflora20 / 323
0.34l89 common bedstrawGalium aparine99 / 943
0.35b90 *field hedge-parsleyTorilis arvensis99 / 37
0.36r91 woodland starLithophragma affine40 / 97
0.36l  (spear-leaved mountain dandelion, Agoseris retrorsa)
0.36l  Sign: "Wildfire..."
0.36r92 coast live oakQuercus agrifolia var. agrifolia4 / 145
0.36l93 mountain mugwortArtemisia ludoviciana ssp. incompta10 / 58
0.36r  (southern honeysuckle, Lonicera subspicata var. denudata)
0.37r94 spear-leaved mountain dandelionAgoseris retrorsa5 / 314
0.37l95 golden yarrowEriophyllum confertiflorum var. confertiflorum20 / 963
0.37l96 Child's collinsiaCollinsia childii99 / 92
0.37l97 diamond-petaled clarkiaClarkia rhomboidea99 / 95
0.37r98 California sweet-cicelyOsmorhiza brachypoda50 / 97
0.37r99 southern honeysuckleLonicera subspicata var. denudata10 / 945
0.38l100~goldenstarBloomeria crocea3 / 215
0.38r  Jct. Five Oaks Trail; go right on it, up the steps; elevation 4380 feet (1335 m)
0.39l101 phlox-leaved bedstrawGalium andrewsii ssp. andrewsii5 / 27
0.39r  Sign: "Five Oaks Trail..."
0.39r  Woodrat's nest
0.39b102 prickly cryptanthaCryptantha muricata30 / 517
0.40r103 California chicoryRafinesquia californica10 / 523
0.40l104 threadstemPterostegia drymarioides30 / 533
0.41l105 southern coast live oakQuercus agrifolia var. oxyadenia5 / 16
0.42l106 white bluecupGithopsis diffusa ssp. candida20 / 22
0.43b107 basketbushRhus trilobata50 / 928
0.47l108 California everlastingGnaphalium californicum5 / 346
0.47b109 Torrey's scrub oakQuercus acutidens10 / 929
0.48l110 giant needlegrassAchnatherum coronatum+5 / 124
0.48l111 wide-throated yellow monkeyflowerMimulus brevipes20 / 913
0.48l112 sand cressCalyptridium monandrum5 / 113
0.48   Check for Filago californica
0.49l113 chamiseAdenostoma fasciculatum10 / 941
0.50r114 California peonyPaeonia californica1 / 119
0.52l115 San Diego peaLathyrus vestitus var. alefeldii5 / 224
0.52b116 common phaceliaPhacelia distans10 / 312
0.52r  (stinging lupine, Lupinus hirsutissimus)
0.52l117 snapdragon campionSilene antirrhina5 / 18
0.52l118 western wallflowerErysimum capitatum ssp. capitatum20 / 322
0.53b119 fringe-podThysanocarpus curvipes30 / 910
0.54   Cross small drainage and curve right
0.54l120 *Italian thistleCarduus pycnocephalus5 / 224
0.54l121 one-sided bluegrassPoa secunda ssp. secunda20 / 225
0.54l122 yarrowAchillea millefolium30 / 517
0.54l123 goldenrodSolidago californica5 / 142
0.54b124 miner's lettuceClaytonia perfoliata ssp. perfoliata30 / 326
0.54l125 American vetchVicia americana var. americana3 / 110
0.54l126 *mouse-ear chickweedCerastium glomeratum20 / 321
0.56r127 slender wheatgrassElymus trachycaulus+20 / 22
0.57r128 blue-eyed grassSisyrinchium bellum2 / 121
0.57b129 *Italian rye-grassLolium multiflorum10 / 120
0.58b130 southern Chinese housesCollinsia concolor99 / 95
0.59r131 Engelmann oakQuercus engelmannii5 / 125
0.60r  (cliff sword fern, Polystichum imbricans ssp. curtum)
0.61b132 poison oakToxicodendron diversilobum30 / 945
0.61l133 *sow thistleSonchus oleraceus1 / 144
0.64   Switchback left
0.65   Switchback right
0.65l134 Laguna manzanitaArctostaphylos glandulosa ssp. adamsii10 / 53
0.65r135 oak mistletoePhoradendron villosum1 / 18
0.68   Switchback left
0.68r136 slender madiaMadia gracilis30 / 920
0.68r137 *darnelLolium temulentum10 / 15
0.69r138 *hedgehog dogtail-grassCynosurus echinatus40 / 11
0.72   Switchback right
0.72b139 *hedge mustardSisymbrium officinale30 / 324
0.75b140 caterpillar phaceliaPhacelia cicutaria var. hispida20 / 217
0.76l141 saw-toothed goldenbushHazardia squarrosa var. grindelioides5 / 137
0.76l142 graceful bedstrawGalium porrigens var. porrigens10 / 45
0.76l143~seashore bentgrassAgrostis pallens3 / 114
0.78   Switchback left
0.78l144 white everlastingGnaphalium canescens ssp. microcephalum3 / 339
0.79b145 Jepson's blue wildryeElymus glaucus ssp. jepsonii30 / 58
0.82l146 *tumble-mustardSisymbrium altissimum20 / 212
0.83r147 snowberrySymphoricarpos albus var. laevigatus+30 / 51
0.87r148 wild tarragonArtemisia dracunculus5 / 325
0.88l  (hollyleaf redberry, Rhamnus ilicifolia)
0.91r149~autumn willowweedEpilobium brachycarpum10 / 56
0.93r150 sacred daturaDatura wrightii20 / 923
0.95l151 red maidsCalandrinia ciliata30 / 924
1.09l152 elk thistleCirsium scariosum2 / 213
1.12l153spwestern? morning-gloryCalystegia (occidentalis ssp. fulcrata?)10 / 38
1.13   Switchback left
1.13r  (bird's-foot fern, Pellaea mucronata var. mucronata)
1.13b154 white fairy lanternCalochortus albus5 / 13
1.14   Switchback right
1.17b155 coast-range melicMelica imperfecta2 / 145
1.17l156 interior live oakQuercus wislizeni var. frutescens1 / 113
1.18l157spPalmer's? ceanothusCeanothus (palmeri?)5 / 16
1.18r158 bird's-foot fernPellaea mucronata var. mucronata1 / 135
1.18l159 hollyleaf redberryRhamnus ilicifolia1 / 149
1.19l160 dwarf athysanusAthysanus pusillus20 / 22
1.19l  Second occurrence of white bluecup, Githopsis diffusa ssp. candida
1.21   Switchback left
1.21r161ssplittle monardellaMonardella nana3 / 2 
1.21   Switchback right at blocked-off road
1.23   Switchback left
1.25   Switchback right
1.26   Switchback left
1.28l162 *common groundselSenecio vulgaris1 / 122
1.28   Switchback right
1.33   Switchback left
1.34l163 *prickly lettuceLactuca serriola2 / 246
1.41b164 dove weedEremocarpus setigerus30 / 528
1.41l165 Sierra gooseberryRibes roezlii var. roezlii5 / 312
1.44l166 strigose sun-cupCamissonia strigulosa3 / 17
1.44b167spannual goosefootChenopodium sp.5 / 1 
 l168~Payson's wild cabbageCaulanthus simulans+2 / 13
1.49   Trail turns left 90°
1.50b169 grand mountain dandelionAgoseris grandiflora5 / 113
1.51r  Jct. Overlook bench
1.51r  (in far distance: bigcone-spruce, Pseudotsuga macrocarpa)
1.54l170 western choke-cherryPrunus virginiana var. demissa5 / 17
1.54   Local high point on trail
1.61   T-jct. with road; go right; elevation ~4970 feet (1515 m); sign ahead: "Midsummit (right); midsummit gate 0.3 mi (right); summit 1.2 mi (right); gateway 1.9 mi (left)"
1.61r171 *yellow salsifyTragopogon dubius2 / 214
1.61l172~Indian milkweedAsclepias eriocarpa4 / 221
1.75l173?rosette with honking leaves like eriogonum?3 / 2 
1.77   Cross small drainage; local low point on road
1.78l174 brackenPteridium aquilinum var. pubescens10 / 114
1.80l175~giant four o'clockMirabilis multiflora var. pubescens1 / 14
1.85   Pass through gate on Saturday and Sunday from 8 a.m. to sunset, April - November; otherwise, turn-around
1.86r176 cream cupsPlatystemon californicus99 / 92
1.96r177 common tidy-tipsLayia platyglossa5 / 16
1.97b178 incense-cedarCalocedrus decurrens20 / 216
2.01c179 *common chickweedStellaria media20 / 129
2.01c180 *common dandelionTaraxacum officinale5 / 17
2.14l  Jct. closed road; elevation 5160 feet (1573 m)
2.15c181 California meadow barleyHordeum brachyantherum ssp. californicum2 / 24
2.17r  Sign: chimney left from Hale telescope siting expedition
2.35l182 confusing fescueVulpia microstachys var. confusa20 / 21
2.38l183 rosy giliaGilia sinuata5 / 11
2.52r  (bitter cherry, Prunus emarginata)
2.60   Y-jct; go right around loop; elevation 5320 feet (1622 m)
2.72l  Volcan Peak; elevation 5353 feet (1632 m); good resting spot at concrete wall
2.79l  Unusual bank of prostrate Rhus trilobata "groundcover".
2.82r184 Veatch's blazing starMentzelia veatchiana5 / 11
2.84   End of loop; turn right and retrace steps on road to upper trail junction
3.83   Upper trail jct.; continue on road; elevation ~4970 feet (1515 m)
3.92b185 *bulbous blue grassPoa bulbosa30 / 93
3.98l186 cliff sword fernPolystichum imbricans ssp. curtum1 / 12
4.00l187 sticky cinquefoilPotentilla glandulosa ssp. glandulosa20 / 318
4.03l  Best field of woodland star, Lithophragma affine
4.03l188 long-spurred plectritisPlectritis ciliosa ssp. insignis5 / 14
4.03l189 blue-eyed Mary Collinsia parviflora5 / 13
4.03l190 goosefoot yellow violetViola purpurea ssp. quercetorum10 / 23
4.04   Switchback right
4.07b191 tuberous sanicleSanicula tuberosa10 / 14
4.08   Switchback left
4.18l  Unusual wild tarragon, Artemisia dracunculus, with all leaves pubescent and divided halfway into three lobes
4.20l192 dense false-giliaAllophyllum gilioides ssp. violaceum20 / 22
4.32r193 woodland strawberryFragaria vesca10 / 14
 l194 foothill penstemonPenstemon heterophyllus var. heterophyllus+ / 12
4.42l195 birch-leaf mountain-mahoganyCercocarpus betuloides var. betuloides3 / 124
4.63l  Sign: "Gateway 0.4 mi (ahead)"
4.63   Lower trail jct.; elevation 4380 feet (1335 m); end guide
5.01   Hubbell Gateway; elevation 4160 feet (1268 m)

Comments On Specific Species

Amsinckia menziesii var. intermedia. The plants at the trailhead were weed-whacked before they could bloom. The variety determination comes from plants near mile 2.1.

Cercis occidentalis, Quercus kelloggii. Both of these have probably been planted at the trailhead. Cercis occidentalis is not found elsewhere on the trail; the first non-planted specimen of Quercus kelloggii is noted at mile 0.27.

Eriogonum fasciculatum var. polifolium. The specimens here are somewhat intermediate to var. foliolosum. Since there are not two distinct varieties here, I have somewhat arbitrarily assigned all the plants to var. polifolium.

Erigeron divergens. These plants are robust perennials here, definitely not the "annual" life form given in the Jepson Manual treatment for this species. Further, they do not look anything like the much-smaller specimens of E. divergens I've seen in the San Bernardino Mountains. As a result, I was almost incredulous that this could be the correct determination. But it is!

Jeri Hirshberg keyed the plants out and kindly informed me of my previous misdetermination of these plants, and I verified her keying on an independent sample. A detailed comparison of the plants to the Flora of North America (FNA) treatment finds excellent agreement in every detail except for the shape of the leaves. The observed leaves are linear to very-narrowly oblanceolate, not ± obovate-spatulate.

Fortunately, the FNA treatment reveals the answer to the difficulties I had in accepting this determination.

Apparently E. divergens has three different chromosome numbers (2n = 18, 27, 36), and a number of different races that develop fruit asexually from the tissue surrounding the embryo sac (this form of asexual reproduction is called "agamospermy").

These asexual races of course never interbreed with other E. divergens plants, and hence produce a number of morphological forms. Some of these forms have received separate species names in the past, and are close to other Erigeron species, such as E. lobatus. Other forms have very short ligules that just barely exceed the phyllaries.

In addition, E. divergens is a very widespread species, found in every state in the western half of the continental U.S. except for Kansas, so there are lots of different forms.

Some of these forms are (short-lived) perennials, like the ones at Volcan. The southern California floras don't mention this at all. Munz says E. divergens is "annual to biennial", and the Jepson Manual simply says "annual". Of course, it is not surprising that a taxon that is an annual in Wyoming might be a perennial in southern California. But it is surprising that a California flora would list it only as an annual if it were commonly observed as a perennial in California.

The Jepson Manual does have a clue that something is going on with E. divergens by the simple word "variable" at the end of the description, but that hardly can be construed to include the change in life form from annual to perennial.

There seems to be a distinct gradient in this taxon in southern California, but there is a big caveat on this observation. Since I'm fitting a trend to just three observations, this gradient may simply be an artifact. The SnBr plants I've seen are about 2 dm (8 inches) high, with a single stem. SnJt plants in Garner Valley are about 3 dm (12 inches) high, with a number of stems from base. The Volcan plants are up to 5 dm (20 inches) high, again with a number of stems from base. The large difference in appearance between between the Garner Valley plants and the Volcan plants are shown in this photograph, which shows an entire Garner Valley plant on the left, and just a single branch of a Volcan plant on the right. The SnBr plants are similar to the plant in this photo. Amazing, huh?

Epilobium canum. Plants in southern California are often indeterminate to subspecies, so I give only the species name. See Comments on the Jepson Manual and A Flora of Southern California by Munz: Epilobium canum.

Achnatherum coronatum. The plants here cannot be clearly determined between A. coronatum and A. parishii, which perhaps are not separate species. On 5/20/07, most of the awns on young seeds have just one bend, a few have a fairly clear two bends, and some have one bend plus perhaps another faint bend. I measured two plants in the field. The first had a stem of 10 dm, and infl of 15-24 cm. Its basal leaves had a maximum width of 3 mm, with cauline leaves ranging to 6 mm in width. The second had a stem of 5.0 dm, and an infl of 15 cm. Its maximum basal leaf width was 4 mm.

The Jepson Manual key is indeterminate, since the maximum leaf basal width of 3-4 mm is supposed to go only with awns with 2 bends. In my plots of infl length vs. stem length, these plants fall into the indeterminate region where both 1 and 2 bend plants are found.

For the determination, I simply used the name with priority if there are not two species.

Kate Shapiro found on 5/30/07 that most of the awns had a slight double bend, so perhaps the awns were just immature on 5/20/07, and the plants are completely consistent with A. coronatum.

Elymus trachycaulus. These plants are inconsistent with the only variety in the San Diego County Plant Checklist, var. trachycaulus. They key to ssp. subsecundus since they have an awn length of 16-21 mm. However, that taxon is supposed to be just "SN, MP". I have also found the same long awns at SnJt, where all the eight vouchers are just given to the species. Given this difficulty, I follow the lead of the vouchers and just determine these plants to the species level.

Symphoricarpos albus var. laevigatus. This is a new species for the San Diego County Plant Checklist, but it turns out it really is not a new species, just a new determination of plants formerly determined as S. mollis.

For pictures and keying of this taxon on this trail, and the strange history of this species in floras of southern California, see Symphoricarpos albus var. laevigatus.

After finding and determining these plants, I wanted to compare these plants to S. mollis. I analyzed samples taken on 6/11/07 of what was supposed to be S. mollis from just west of Lake Henshaw and from the Inaja Memorial between Santa Ysabel and Julian. Those plants also turned out to be S. albus, with 11 characteristics that fit only S. albus, and zero characteristics that fit only S. mollis. Hence it appears that S. albus is the common montane species in San Diego County.

Thus although this taxon is listed as only being on this trail among all my plant trail guides, that will probably change when I review the determinations made on those trails in the future.

Caulanthus simulans. Kate Shapiro observed this species in 2006, but it wasn't found in May 2007.

Penstemon heterophyllus var. heterophyllus. The location of this species is after the strawberry and before the Cercocarpus.

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Copyright © 2007 by Tom Chester.
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Last update: 14 June 2007.