Flora of Hidden Lake Drainage Basin, San Jacinto Mountain

Procedure For Compiling The Checklist
Important Caveat


Hidden Lake is a vernal pool at San Jacinto Mountain at an elevation of about 8700 feet. The pool fills with water in spring in normal rainfall years, and then dries up during the summer. As the pool recedes, very specialized plants grown along the margins of the water.

This is a flora of the Hidden Lake Drainage Basin, compiled from vouchers and from our fieldwork. It includes species found in the Lake itself, as well as species found in the surrounding territory that drains to the Lake, an area of about 0.25 miles north-south and 0.20 miles east-west. The total area is about 0.05 square miles (=33 acres = 13.5 hectares). See the map below for the boundaries of the drainage basin.

So far, we have seen no non-native species in this area, and there is only a single voucher of one from here.

If you go to Hidden Lake, please do not trample the plant species along the margins of the Lake! Footprints from visitors can easily take a huge toll among these very specialized plants that live only here, by killing them directly by your boots and indirectly by changing the soil texture of their home. Staying away from the lake margins, and heading to Desert View on the well-established path, is the best way to respect the plants living here and allow them to continue to thrive in this special location. The plants are quite uniform around the entire lake, and hence you will see almost all the species by staying on the well-established path.


Hidden Lake is located 0.9 air miles south of the upper tram station, at the lower right corner of the following map. The dashed line shows the margins of the Hidden Lake Drainage Basin.

Procedure For Compiling The Checklist

The Checklist was compiled from online vouchers, and from field work done by the authors on 25 June 2008 and on 21 August 2012.

The vouchers were obtained on 27 June 2008 and on 26 August 2017 from combining two searches on each date of the Consortium of California Herbaria, a search for Lake Surprise and a search for Hidden Lake. Only vouchers that appeared to be from the drainage area were kept; vouchers given with localities such as trail on way to Hidden Lake were ignored. A total of 62 taxa were vouchered.

The field work from 25 June 2008 and 21 August 2012 found 43 taxa, of which 26 were also in the voucher list.

The total list includes 79 taxa.

Important Caveat

We have not looked at any of the vouchers yet, so we cannot vouch for their determinations. We have checked only the names of the taxa to make sure it was not unreasonable for them to occur here.

Checklist for Hidden Lake Drainage Basin

Basic information about the checklist presentation and links:

An asterisk before the Common Name indicates a non-native taxon.

There are three columns that follow the names for each taxa.

The first column (header #V) gives the number of vouchers found in the Hidden Lake Drainage Basin from the procedure detailed above.

The second column (header HL) denotes those taxa found within the margin of the highest waterline of the lake. There is some uncertainty about whether species known only from vouchers whose locality is just Hidden Lake were actually found within the lake margins or not. We've used our judgment as to which of those probably were found within the lake.

The third column (header #Pls) gives a rough estimate of the number of plants for taxa seen in our field surveys, with a maximum value of 99 plants. The main intent of this column is to indicate the species for which we found few plants.

Version for printing, without lines and other text on this page: html (3 pages) or pdf Clickbook booklet (1 double-sided page). (See printing instructions for an explanation of these options)

#FamilyScientific Name(*)Common Name#VHL#Pls
1WoodsiaceaeCystopteris fragilisbrittle bladder fern  4
2PinaceaeAbies concolorwhite fir  20
3PinaceaePinus contorta ssp. murrayanalodgepole pine3 20
4PinaceaePinus jeffreyiJeffrey pine  20
5PinaceaePinus lambertianasugar pine  20
6AsteraceaeAntennaria rosearosy everlasting, pussytoes1  
7AsteraceaeEricameria nauseosa var. bernardinaSan Bernardino rubber rabbitbrush  10
8AsteraceaeGnaphalium palustrewestern marsh cudweed7HL99
9AsteraceaeHieracium horridumprickly hawkweed1  
10AsteraceaeSolidago velutina ssp. californicagoldenrod  20
11AsteraceaeSonchus asper ssp. asper*prickly sow thistle1  
12BoraginaceaeCryptantha micrantha var. lepidamountain red-root cryptantha9 50
13BrassicaceaeBoechera retrofracta Xmountain rock-cress  1
14BrassicaceaeDraba saxosaSan Jacinto rock draba1  
15BrassicaceaeRorippa curvisiliquacurvepod yellow-cress1HL 
16CaryophyllaceaeSagina decumbens ssp. occidentaliswestern pearlwort1HL 
17CaryophyllaceaeSilene parishiiParish's campion1 10
18CaryophyllaceaeSilene verecundawhite catch-fly2 1
19CrassulaceaeCrassula aquaticaaquatic pygmy-weed9HL99
20ElatinaceaeElatine brachyspermashort-seed waterwort2HL 
21ElatinaceaeElatine californicaCalifornia waterwort1HL 
22EricaceaeArctostaphylos patulagreen-leaf manzanita  10
23EricaceaePyrola aphyllaleafless wintergreen  2
24EricaceaePyrola picta s.l.white-veined wintergreen1  
25EricaceaeSarcodes sanguineasnow-plant1 1
26FabaceaeAcmispon americanus var. americanusSpanish clover2HL 
27FabaceaeAcmispon nevadensis var. davidsoniiDavidson's lotus2HL 
28FabaceaeAcmispon nevadensis var. nevadensisSierra Nevada lotus3HL99
29FabaceaeLupinus hyacinthinusSan Jacinto lupine4 1
30FabaceaeTrifolium monanthum ssp. grantianummountain carpet clover1HL 
31FagaceaeChrysolepis sempervirensbush chinquapin  10
32FagaceaeQuercus chrysolepiscanyon live oak  3
33HydrangeaceaePhiladelphus microphylluslittle-leaf mock orange1 20
34LamiaceaeMonardella nanalittle monardella1  
35LamiaceaeSalvia pachyphyllarose sage1  
36LamiaceaeTrichostema austromontanum ssp. compactumHidden Lake bluecurls13HL99
37MontiaceaeCalyptridium parryi var. parryiParry's sand cress3HL20
38OnagraceaeEpilobium canum ssp. latifoliummountain California-fuchsia1 70
39OnagraceaeGayophytum decipiensdeceiving gayophytum2  
40OnagraceaeGayophytum diffusum ssp. parviflorumgroundsmoke3 20
41PhrymaceaeMimulus breweriBrewer's monkeyflower8HL99
42PhrymaceaeMimulus floribundusfloriferous monkeyflower2HL 
43PhrymaceaeMimulus pilosusfalse monkeyflower4HL50
44PhrymaceaeMimulus primuloidesprimrose monkeyflower3HL 
45PhrymaceaeMimulus suksdorfiiSuksdorf's monkeyflower3HL99
46PlantaginaceaeKeckiella rothrockii var. jacintensisSan Jacinto Mts. keckiella4 20
47PlantaginaceaeVeronica peregrina ssp. xalapensispurslane speedwell5HL99
48PolemoniaceaeLinanthus jaegeriSan Jacinto prickly phlox3  
49PolemoniaceaeLinanthus pungensgranite prickly phlox1 10
50PolygonaceaeEriogonum nudum var. pauciflorumnaked buckwheat1  
51PolygonaceaeEriogonum wrightii var. subscaposumWright's buckwheat1  
52PolygonaceaeSidotheca caryophylloideschickweed oxytheca5  
53RhamnaceaeCeanothus cordulatusmountain whitethorn  1
54RosaceaeCercocarpus ledifoliuscurl-leaf mountain-mahogany  10
55RosaceaeHolodiscus discolor var. microphyllusmountain spray  5
56RosaceaeHorkelia clevelandii var. clevelandiiCleveland's horkelia2HL 
57RubiaceaeGalium parishiiParish's bedstraw6 5
58ScrophulariaceaeLimosella acaulisstemless mudwort8HL99
59CyperaceaeCarex fractafragile sheath sedge  10
60CyperaceaeCarex multicostatamany-ribbed sedge6  
61CyperaceaeCarex subfuscabrown sedge  50
62CyperaceaeCyperus squarrosusbearded flatsedge6HL 
63CyperaceaeEleocharis acicularis var. acicularisneedle spikerush6HL99
64CyperaceaeEleocharis bellaneedle spikerush5HL 
65CyperaceaeEleocharis macrostachyacommon spikerush2HL99
66CyperaceaeLipocarpha occidentaliswestern hemicarpha2HL 
67JuncaceaeJuncus bufoniustoad rush7HL 
68JuncaceaeJuncus bufonius var. bufoniustoad rush2HL99
69JuncaceaeJuncus bufonius var. occidentaliswestern toad rush1HL 
70JuncaceaeJuncus duraniiDuran's rush5HL 
71JuncaceaeJuncus mexicanusMexican rush HL99
72JuncaceaeJuncus tiehmiiTiehm's rush1HL 
73JuncaceaeJuncus triformisYosemite dwarf rush1HL 
74PoaceaeAgrostis idahoensisIdaho bentgrass5HL 
75PoaceaeAgrostis scabrarough bentgrass1HL 
76PoaceaeElymus elymoidessquirreltail2  
77PoaceaeMuhlenbergia filiformispullup muhly10HL 
78PoaceaeMuhlenbergia minutissimaannual muhly1HL 
79PotamogetonaceaePotamogeton diversifoliusdiverse-leaved pondweed16HL50

Voucher data provided by the participants of the Consortium of California Herbaria (ucjeps.berkeley.edu/consortium/).

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Copyright © 2008-2017 by Tom Chester, Dave Stith, James Dillane, Michael Charters, and Eric Baecht
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Last update: 26 August 2017