Flora of Jackson Lake Area, San Gabriel Mountains
Table of Contents
Origin of Jackson Lake
Aquatic Plants, Distinguishing Characteristics and Photographs
Drying Lake Area Margin Plants
Absence of Riparian Plants
Fig. 1. View of Jackson Lake from the Jackson Lake Trail. Photo by Tom Chester, taken on 5 September 2015 looking north / northeast. Click on the picture for a larger version.
Jackson Lake is one of the very few natural lakes in the San Gabriel Mountains, and hence contains aquatic plants not seen in the vast majority of the area of the San Gabriels. In fact, one or more of the aquatic species seen here, listed in Table 1 below, are found at only five other georeferenced voucher locations in the San Gabriels: Crystal Lake; Lost Lake (Lone Pine Canyon); confluence of West Fork and North Fork of San Gabriel River; Caldwell Lake; and Lytle Creek Canyon.
Interestingly, although there is a lot of water in Jackson Lake, typical riparian plants are missing from its flora! This testifies that there is something different about the origin of Jackson Lake, from the usual lakes and ponds fed by water from wet drainages.
Origin of Jackson Lake
Jackson Lake has been described as a sag pond, but that is not correct. A sag pond is a feature created by sagging of the land surface that then fills with water. The sagging could be caused by subsidence of land between two branches of an earthquake fault, or by slumping of the top of a landslide area.
Instead, Jackson Lake appears to have been created by simple movement of the upper part of its drainage along the San Andreas Fault to the point where the drainage was blocked by its own drainage divide (see Field Guide to the San Andreas Fault by David Lynch).
Fig. 2 shows a cartoon model of the drainage prior to movement along the fault, and after the fault has moved one bank of its drainage divide enough to block at least partially the upper part of the drainage.
Fig. 2. Cartoon model of how Jackson Lake was probably created in the creek drainage by movement along the San Andreas Fault. The left diagram shows the drainage and its banks (drawn at the drainage divides with the two neighboring drainages) before movement along the Fault. The right diagram shows the right-lateral displacement of the drainage and its banks, with the segment of its own drainage left bank, on the other side of the fault, now blocking the original trend of the upper drainage.
Fig. 3 is a Google Earth view showing that the drainage that goes through Jackson Lake has been offset to the right along the San Andreas Fault, with its former side bank now in line with the upper part of its drainage (see also large scale view from the west). As a result, the creek has had to cut its way through its former side bank. It hasn't been able to cut its bank down quickly enough to prevent a partial blockage of the drainage, forming the lake.
Fig. 3. View of Jackson Lake from the south in Google Earth. Click on the picture for a larger version. See also view from farther above from the west.
Jackson Lake apparently was originally a smaller pond that was enlarged "sometime prior to 1920" by construction of a dam to block the outlet of the pond (see What will happen to Jackson Lake?), which was reinforced soon after the Forest Service took over the area in 1940. The Big Pines Highway (N2) is constructed on top of that dam.
The former outlet of the lake now has an outlet tunnel with a valve that can be opened to drain the lake. The lake was apparently drained in the winter of 2013-2014 after a man died trying to save a child who had fallen through the ice on the surface of the lake.
Drying Lake Area Margin Plants
Absence of Riparian Plants
Aquatic Plants, Distinguishing Characteristics and Photographs
Aquatic plants are clearly the star of the show here. The ones present here, and their distingushing characteristics, are given in Table 1.
There might be a non-vascular plant present at Jackson Lake that is often confused with aquatic flowering plants, Chara, muskgrass or skunkweed. Because of this potential confusion, we've added this to Table 1.
Table 1. The Aquatic Vascular Plant Species of Jackson LakeAll photographs from Calphotos except the first one; click on the pictures for the larger original versions.
Distinguishing Characteristics Scientific Name Common Name Photograph Not a Vascular Plant, but looks similar to one!
No vascular system; no flowers; always entirely submersed in water; 6-16 whorled branchlets per node; with foul, musty almost garlic-like odor; branchlets often with grainy texture due to calcium deposits (see Weed info - Branched Algae; and Algae and Weed Identification)
Chara species muskgrass, skunkweed
© Tom Chester
Leaves whorled, 3-11 per node, each with 2-4 segments, plant entirely submersed in water Ceratophyllum demersum coon's tail
© Neal Kramer
Submersed leaves whorled, 3-6 per node, each with up to 28 segments; inflorescence above water Myriophyllum sp., possibly sibiricum Siberian milfoil
Leaves opposite Zannichellia palustris horned pondweed
© Neal Kramer
Leaves alternate, leaf blade serrate, inflorescence floating on water or above water Potamogeton crispus *crispate-leaved pondweed
© Br. Alfred Brousseau, Saint Mary's College
Leaves alternate, leaf blade elliptic to oblanceolate, inflorescence floating on water or above water, Potamogeton illinoensis shining pondweed
© Neal Kramer
Leaves alternate, leaf thread-like, inflorescence under water Stuckenia pectinata (=Potamogeton pectinatus) fennel-leaved pondweed
© Esperanza Pimentel
Leaves alternate, leaf blade linear, inflorescence floating on water or above water Potamogeton foliosus ssp. foliosus leafy pondweed
© Neal Kramer
Drying Lake Area Margin Plants
The flora of the Jackson Lake area is very unusual. It consists of two nearly-disjunct sets of species. The species found in and around Jackson Lake are for the most part not found elsewhere in the area, and vice versa.
For example, in our survey on 5 September 2015, we found 138 taxa. Of those 138 taxa, 95 were found only on the trail above Jackson Lake; 43 of those taxa were found in, or immediately-around, Jackson Lake; and only five taxa were found in both places!
The checklist below identifies those taxa found only in, and in the drying margins of, Jackson Lake, from our field survey.
Absence of Riparian Plants
The first thing Jane Strong noticed, when she saw the first voucher flora of Jackson Lake presented on this page, was that typical riparian species were missing! In riparian areas in the San Gabriel Mountains, one finds species such as bracken, yarrow, columbine, orchids, Parish's lupine, scarlet and other monkeyflowers, and many additional rush and sedge species.
The unusual origin of Jackson Lake detailed above accounts for the lack of riparian plants. There isn't a high water table here that feeds the lake from typical riparian streams. Instead, the drainages in this area typically carry water only for brief times during rainfall, with the water all rushing to the desert floor to the north. Because of the natural (and unnatural) dam, the water gets trapped here in the lake when there is runoff.
The checklist gives three varieties of Ericameria nauseosa, but there are actually only two distinct varieties here. Var. bernardina is unambiguously distinct, but the other variety is intermediate between var. mohavensis and var. oreophila, and hence sometimes is vouchered under one name, and sometimes under the other name.
This checklist includes:
- species vouchered from the area around Jackson Lake, noted by entries in the column with header #V;
- the results of a survey done on 5 September 2015 of the Jackson Lake Trail, from Jackson Lake to the PCT, including the portion of the area around Jackson Lake near the parking area, noted by entries in the column with header #Pls;
- additional species found in a survey of the PCT from Lightning Ridge to Vincent Gap;
- additional species vouchered in the area of that PCT section.
The procedure for obtaining the vouchers was as follows.
Vouchers from the Consortium of California Herbaria were searched on 4 September 2015 for all Los Angeles County vouchers with Jackson Lake in their locality, augmented by a search for georeferenced vouchers between 34.38 and 34.40° N. latitude and -117.75 and -117.71° E. longitude. Duplicate vouchers were removed, and vouchers not in the area close to Jackson Lake were removed.
The above procedure resulted in 573 vouchers of 231 taxa. Table 2 lists the top voucher collectors. As is usually the case, Dick Swinney is the #1 voucher collector, responsible for 31% of all the vouchers.
Table 2. Dominant Voucher Collectors
# of Vouchers % of all Vouchers Collector 176 31% R. G. Swinney 134 23% T. S. Ross 73 13% R. F. Thorne 48 8% B. C. Templeton
The vouchers are mostly from Jackson Lake itself and areas within 1.3 miles of Jackson Lake; see map of accepted voucher locations. This map uses the clustering algorithm at the Consortium. The numbers inside the colored circles show the number of vouchers from each cluster. Jackson Lake is at the center of the map, at the red circle showing 147 vouchers.
The seven taxa in Table 3 were rejected from the voucher list for the given reason, leaving 224 vouchered taxa in the checklist.
Table 3. Taxa Rejected from the Voucher List
Scientific Name Reason for Rejection Cupressus arizonica ssp. nevadensis Planted by the Forest Service at Ball Flat Ericameria parryi Probable misdetermination Galium biflorum Typo Gayophytum nuttallii see note under Gayophytum diffusum parviflorum in JM eflora: "most small-flowered plants assigned by Munz, others to Gayophytum nuttallii belong here" Horkelia bolanderi Probable misdetermination Opuntia basilaris var. treleasei Probable misdetermination Penstemon eatonii Probable misdetermination
A field survey was done on 5 September 2015 of the Jackson Lake Trail, from Jackson Lake to the PCT, including the portion of the area around Jackson Lake near the parking area, by the authors. A total of 138 taxa were observed. Of those 138 taxa, 103 taxa were vouchered from the Jackson Lake area, and 33 taxa were additions to the Jackson Lake Flora.
The total checklist below contains 327 taxa. Of those, a total of 265 taxa are in the checklist from the Jackson Lake area up to the junction of the PCT. An additional 62 taxa are given in the Checklist from surveys of the PCT from Lightning Ridge to Vincent Gap, and from species vouchered in the area of that PCT section. Some of those 62 taxa are probably found in the Jackson Lake area, but many probably are not found there. After further surveys at prime time, we will delete those additional species that have not been found here.
See Information about the order in which the species are presented, and the links from the Scientific Name and Common Name.
The column JL indicates whether a taxon was only found in, or immediately around, Jackson Lake, in the field survey. We have not yet gone through the vouchers to see which additional species are only found in or immediately around Jackson Lake.
The column #V gives the number of vouchers for the Jackson Lake area, with a maximum of 9 vouchers recorded in that field.
The column #Pls gives the number of plants for each observed species on the survey of 5 September 2015, up to a maximum of 99 plants. If there is uncertainty in the determination, the number has a symbol associated with it, ~ for a probable, but not certain, determination, sp (for "species") or ? for more uncertain determinations.
Species with no entry in either of these two colums are taxa found just outside the Jackson Lake Area, and may or may not be found in the Jackson Lake area. They were included to make the checklist more complete for future surveys.
Sequoiadendron giganteum, giant sequoia, has been planted in the campground, and is not native to this area, as is probably Calocedrus decurrens, incense-cedar. It is likely that the two specimens of Pinus coulteri, Coulter pine, found at the beginning of the Jackson Lake Trail, have also been planted. We've marked only the giant sequoia as not-native here since we are not certain about the other two.
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# Fam Scientific Name (*)Common Name JL #V #Pls Ferns 1 Equ Equisetum arvense field horsetail 2 Equ Equisetum laevigatum smooth scouring rush 2 3 Pte Pellaea mucronata var. californica California cliff-brake 1 4 Pte Pellaea mucronata var. mucronata bird's-foot fern Gymnosperms 5 Cup Calocedrus decurrens incense-cedar JL 2 2 6 Cup Juniperus californica California juniper 1 7 Cup Sequoiadendron giganteum *giant sequoia JL 5 8 Pin Abies concolor white fir 2 50 9 Pin Pinus coulteri Coulter pine 2 10 Pin Pinus jeffreyi Jeffrey pine 99 11 Pin Pinus lambertiana sugar pine 2 15 12 Pin Pinus monophylla pinyon pine 1 4 13 Pin Pinus ponderosa var. pacifica ponderosa pine 1 Ceratophyllales 14 Cer Ceratophyllum demersum coon's tail 1 Eudicots 15 Ado Sambucus nigra ssp. caerulea blue elderberry 5 16 Ama Amaranthus albus *tumble pigweed JL 3 99 17 Ama Amaranthus blitoides *mat amaranth 1 18 Api Lomatium dissectum var. multifidum fern-leaved lomatium 1 ~1 19 Api Lomatium mohavense Mojave lomatium 1 20 Api Lomatium nevadense var. parishii Parish's lomatium 2 21 Api Osmorhiza berteroi mountain sweet-cicely 2 22 Api Tauschia parishii Parish's tauschia 4 20 23 Apo Apocynum androsaemifolium spreading dogbane 24 Apo Asclepias californica California milkweed 6 10 25 Ast Agoseris grandiflora var. grandiflora grand mountain dandelion 26 Ast Agoseris retrorsa spear-leaved mountain dandelion ~1 27 Ast Ambrosia acanthicarpa bur-ragweed JL 1 99 28 Ast Anisocoma acaulis scale-bud 29 Ast Artemisia douglasiana mugwort 3 30 Ast Artemisia dracunculus wild tarragon 2 30 31 Ast Artemisia tridentata big sagebrush 4 99 32 Ast Chaenactis glabriuscula var. glabriuscula yellow pincushion 3 33 Ast Chaenactis santolinoides santolina pincushion 1 30 34 Ast Cirsium occidentale var. californicum California thistle 2 5 35 Ast Corethrogyne filaginifolia California-aster 36 Ast Dieteria canescens var. canescens hoary-aster 37 Ast Ericameria nauseosa var. bernardina San Bernardino rubber rabbitbrush 4 50 38 Ast Ericameria nauseosa var. mohavensis Mohave common rabbitbrush 39 Ast Ericameria nauseosa var. oreophila threadleaf common rabbitbrush 2 1 40 Ast Erigeron canadensis horseweed JL 1 99 41 Ast Erigeron divergens spreading fleabane 2 42 Ast Erigeron foliosus var. foliosus leafy daisy 3 50 43 Ast Eriophyllum confertiflorum var. confertiflorum golden yarrow 1 30 44 Ast Euthamia occidentalis western goldenrod 1 45 Ast Gnaphalium palustre western marsh cudweed 1 46 Ast Lactuca serriola *prickly lettuce JL 2 1 47 Ast Lessingia glandulifera var. glandulifera sticky lessingia 1 48 Ast Malacothrix californica California dandelion 2 49 Ast Malacothrix glabrata desert dandelion 1 50 Ast Packera ionophylla Tehachapi ragwort 2 10 51 Ast Pleiacanthus spinosus thorny skeleton-plant 52 Ast Pseudognaphalium thermale slender everlasting 2 53 Ast Senecio flaccidus var. douglasii bush senecio 1 54 Ast Solidago velutina ssp. californica goldenrod 2 99 55 Ast Sonchus asper ssp. asper *prickly sow thistle JL 1 1 56 Ast Stephanomeria exigua ssp. coronaria slender wreathplant 3 5 57 Ast Stephanomeria virgata twiggy wreath plant 58 Ast Taraxacum officinale *common dandelion JL 3 1 59 Ast Tetradymia canescens spineless horsebrush 30 60 Bet Alnus rhombifolia white alder 1 61 Bor Cryptantha affinis common cryptantha 1 62 Bor Cryptantha echinella prickly cryptantha 1 63 Bor Cryptantha muricata var. denticulata prickly-nut cryptantha 64 Bor Cryptantha muricata var. jonesii Jones' prickly-nut cryptantha 65 Bor Cryptantha muricata var. muricata showy prickly-nut cryptantha 2 66 Bor Cryptantha simulans pine cryptantha 7 67 Bor Eriodictyon parryi poodle-dog bush 68 Bor Eriodictyon trichocalyx var. trichocalyx smoothleaf yerba santa 99 69 Bor Nama californica California fiddleleaf 1 70 Bor Pectocarya penicillata combseed 1 71 Bor Phacelia austromontana southern Sierra phacelia 72 Bor Phacelia bicolor var. bicolor two-colored phacelia 1 73 Bor Phacelia cicutaria var. hispida caterpillar phacelia 1 74 Bor Phacelia curvipes curve-stem phacelia 75 Bor Phacelia davidsonii Davidson's phacelia 4 76 Bor Phacelia fremontii Fremont's phacelia 1 77 Bor Phacelia imbricata imbricate phacelia 1 99 78 Bor Phacelia mohavensis Mojave phacelia 2 79 Bor Phacelia ramosissima branching phacelia 7 80 Bra Barbarea orthoceras winter cress 6 81 Bra Boechera arcuata arched elegant rock-cress 82 Bra Boechera californica California elegant rock-cress 83 Bra Boechera repanda Yosemite rockcress 2 10 84 Bra Boechera retrofracta X mountain rock-cress 85 Bra Caulanthus amplexicaulis clasping-leaved caulanthus 1 86 Bra Caulanthus major slender wild cabbage 4 20 87 Bra Descurainia sophia *herb sophia 1 88 Bra Erysimum capitatum var. capitatum western wallflower 3 99 89 Bra Hirschfeldia incana *shortpod mustard JL 1 10 90 Bra Lepidium virginicum ssp. menziesii wild pepper-grass JL 2 2 91 Bra Sisymbrium altissimum *tumble-mustard 3 92 Cac Opuntia basilaris var. brachyclada short-joint beavertail 1 93 Cap Lonicera subspicata var. denudata southern honeysuckle sp10 94 Cap Symphoricarpos rotundifolius var. parishii Parish's snowberry 1 4 95 Car Eremogone macradenia var. arcuifolia desert sandwort 2 25 96 Car Silene verecunda white catch-fly 4 50 97 Che Atriplex rosea *tumbling oracle 3 98 Che Chenopodium atrovirens forest goosefoot 99 Che Chenopodium fremontii Fremont's goosefoot JL 2 99 100 Che Chenopodium leptophyllum thin-leaved goosefoot 101 Che Chenopodium murale *nettle-leaved goosefoot 1 102 Che Chenopodium pratericola meadow goosefoot 103 Che Chenopodium strictum var. glaucophyllum *white-leaved goosefoot 104 Che Dysphania botrys *Jerusalem oak 1 105 Che Salsola gobicola *hybrid thistle 106 Con Calystegia occidentalis ssp. fulcrata western morning-glory 2 50 107 Con Calystegia peirsonii Peirson's morning-glory 108 Con Cuscuta californica var. californica California dodder 40 109 Cor Cornus sericea ssp. occidentalis western dogwood 1 110 Cor Cornus sericea ssp. sericea red osier dogwood 3 111 Cra Dudleya cymosa ssp. pumila canyon dudleya 112 Ela Elaeagnus angustifolia *Russian olive 6 113 Eri Arctostaphylos patula green-leaf manzanita 114 Eri Sarcodes sanguinea snow-plant 5 115 Eup Chamaesyce serpyllifolia ssp. serpyllifolia thyme-leafed spurge 3 116 Fab Acmispon americanus var. americanus Spanish clover JL 2 99 117 Fab Acmispon nevadensis var. davidsonii Davidson's lotus 3 30 118 Fab Acmispon procumbens var. procumbens silky California broom 4 3 119 Fab Astragalus douglasii var. douglasii Jacumba milk-vetch 1 10 120 Fab Astragalus lentiginosus var. antonius San Antonio milk-vetch 121 Fab Astragalus leucolobus Big Bear Valley woollypod 3 122 Fab Astragalus purshii var. lectulus Pursh's milk-vetch 3 123 Fab Hosackia crassifolia var. crassifolia broad-leaved lotus 2 15 124 Fab Lupinus elatus silky lupine 125 Fab Lupinus excubitus var. austromontanus mountain grape-soda lupine 30 126 Fab Lupinus formosus var. formosus western lupine 2 127 Fab Lupinus hyacinthinus San Jacinto lupine 128 Fab Melilotus albus *white sweetclover JL 1 99 129 Fab Trifolium variegatum variegated clover 1 130 Fab Trifolium wormskioldii cows clover 4 131 Fag Chrysolepis sempervirens bush chinquapin 132 Fag Quercus chrysolepis canyon live oak 2 99 133 Fag Quercus john-tuckeri Tucker's oak 4 1 134 Fag Quercus kelloggii California black oak 9 99 135 Gar Garrya flavescens ashy silk tassel 3 136 Gen Frasera neglecta pine green-gentian 6 25 137 Ger Erodium cicutarium *redstem filaree JL 20 138 Gro Ribes cereum var. cereum wax currant 5 2 139 Gro Ribes lasianthum alpine gooseberry 1 140 Gro Ribes nevadense mountain pink currant 6 99 141 Gro Ribes roezlii var. roezlii Sierra gooseberry 6 15 142 Gro Ribes velutinum desert gooseberry 143 Hal Myriophyllum ~sibiricum Siberian milfoil 3 144 Lam Monardella linoides ssp. stricta narrowleaf monardella 1 30 145 Lam Scutellaria siphocampyloides curve-flowered skullcap 2 146 Loa Mentzelia congesta clustered blazing star 1 147 Loa Mentzelia dispersa scattered blazing star 4 148 Mal Fremontodendron californicum flannelbush 2 99 149 Mal Malacothamnus fremontii Fremont's bush mallow 3 4 150 Mal Malva neglecta *common mallow JL 2 50 151 Mon Calyptridium monandrum sand cress 1 152 Mon Claytonia exigua ssp. exigua little spring beauty 153 Mon Claytonia parviflora ssp. viridis green miner's lettuce 1 154 Mon Claytonia perfoliata ssp. perfoliata miner's lettuce 1 155 Mon Claytonia rubra ssp. rubra red-stemmed miner's lettuce 1 156 Mon Lewisia rediviva var. minor bitter root 157 Ona Camissonia campestris ssp. campestris field suncup 1 158 Ona Camissoniopsis pallida ssp. pallida pale suncup 159 Ona Clarkia rhomboidea diamond-petaled clarkia 160 Ona Epilobium brachycarpum autumn willowweed 1 161 Ona Epilobium canum ssp. latifolium mountain California-fuchsia 1 99 162 Ona Epilobium ciliatum willowherb JL 1 99 163 Ona Gayophytum decipiens deceiving gayophytum 1 164 Ona Gayophytum diffusum ssp. parviflorum groundsmoke 3 165 Ona Gayophytum oligospermum pinegrove groundsmoke 40 166 Ona Oenothera californica ssp. californica California evening-primrose 3 167 Ona Oenothera elata ssp. hirsutissima Hooker's evening-primrose JL ~1 168 Oro Castilleja affinis ssp. affinis coast Indian paintbrush 169 Oro Castilleja applegatei ssp. martinii Martin's paintbrush 35 170 Oro Castilleja plagiotoma Mojave Indian paintbrush 171 Oro Cordylanthus nevinii Nevin's bird's beak 99 172 Oro Orobanche californica ssp. feudgei California broomrape 173 Oro Orobanche fasciculata clustered broomrape 11 174 Oro Pedicularis semibarbata pine lousewort 1 1 175 Pap Argemone munita prickly poppy 1 20 176 Pap Ehrendorferia chrysantha golden ear drops 177 Phr Mimulus fremontii var. fremontii Fremont's monkeyflower 2 178 Phr Mimulus guttatus common monkeyflower 1 179 Phr Mimulus rubellus little redstem monkeyflower 1 180 Phr Mimulus suksdorfii Suksdorf's monkeyflower 1 181 Pla Collinsia callosa desert collinsia 2 182 Pla Collinsia torreyi var. wrightii Wright's collinsia 3 183 Pla Penstemon centranthifolius scarlet bugler 3 184 Pla Penstemon grinnellii var. grinnellii Grinnell's beardtongue 20 185 Pla Penstemon labrosus San Gabriel beardtongue 2 186 Pla Penstemon rostriflorus beaked penstemon 1 99 187 Pla Penstemon speciosus showy penstemon 2 188 Pla Plantago major *common plantain JL 3 99 189 Pla Veronica anagallis-aquatica *water speedwell JL 1 99 190 Pol Allophyllum gilioides ssp. gilioides dense false-gilia 191 Pol Allophyllum gilioides ssp. violaceum dense false-gilia 1 192 Pol Allophyllum integrifolium white false-gilia 193 Pol Eriastrum densifolium giant woolly-star 2 50 194 Pol Eriastrum sapphirinum sapphire woolly-star 1 195 Pol Gilia brecciarum ssp. brecciarum Nevada gilia 1 196 Pol Gilia diegensis coastal gilia 1 197 Pol Gilia leptantha ssp. transversa fine-flower gilia 198 Pol Gilia modocensis Modoc gilia 1 199 Pol Gilia ochroleuca ssp. vivida San Gabriel Mountain gilia 2 ~20 200 Pol Leptosiphon breviculus Mojave linanthus 2 201 Pol Linanthus concinnus San Gabriel linanthus 2 202 Pol Phlox diffusa spreading phlox 3 203 Pol Saltugilia splendens ssp. grantii Grant's gilia 1 204 Pol Saltugilia splendens ssp. splendens splendid gilia 3 ssp5 205 Pol Acanthoscyphus parishii var. parishii Parish's oxytheca 8 206 Pol Eriogonum baileyi var. baileyi Bailey's buckwheat 3 207 Pol Eriogonum cithariforme var. agninum Cithara buckwheat 3 208 Pol Eriogonum davidsonii Davidson's buckwheat 7 99 209 Pol Eriogonum fasciculatum var. polifolium California buckwheat 1 2 210 Pol Eriogonum maculatum spotted buckwheat 7 211 Pol Eriogonum nudum var. pauciflorum naked buckwheat 99 212 Pol Eriogonum pusillum yellow-turbans 213 Pol Eriogonum umbellatum var. munzii sulphur buckwheat 3 99 214 Pol Eriogonum umbellatum var. subaridum desert sulfur buckwheat 5 215 Pol Eriogonum viridescens bright green buckwheat 1 216 Pol Eriogonum wrightii var. subscaposum Wright's buckwheat 5 99 217 Pol Polygonum aviculare ssp. depressum *knotweed JL 2 99 218 Pol Rumex crispus *curly dock JL 2 25 219 Pol Rumex salicifolius willow-leaved dock JL 2 2 220 Ran Clematis ligusticifolia virgin's bower JL 5 2 221 Ran Delphinium parishii ssp. parishii Parish's larkspur 222 Ran Delphinium parryi blue larkspur 223 Ran Delphinium patens ssp. montanum spreading larkspur 224 Ran Ranunculus cymbalaria Rocky Mountain buttercup JL 4 99 225 Ran Thalictrum fendleri Fendler's meadow-rue 1 226 Rha Ceanothus cordulatus mountain whitethorn 2 4 227 Rha Ceanothus cuneatus buck brush 1 228 Rha Ceanothus integerrimus var. macrothyrsus deer brush 229 Rha Ceanothus vestitus Mojave ceanothus 1 99 230 Rha Frangula californica California coffeeberry 231 Rha Rhamnus ilicifolia hollyleaf redberry 232 Ros Amelanchier utahensis Utah service-berry 4 2 233 Ros Cercocarpus betuloides var. betuloides birch-leaf mountain-mahogany 99 234 Ros Drymocallis lactea var. lactea Nevada cinquefoil 2 sp10 235 Ros Holodiscus discolor var. microphyllus mountain spray 236 Ros Horkelia rydbergii Rydberg's horkelia 2 237 Ros Potentilla gracilis var. fastigiata slender cinquefoil 1 238 Ros Prunus emarginata bitter cherry 1 239 Ros Prunus virginiana var. demissa western choke-cherry JL 6 99 240 Ros Purshia tridentata var. glandulosa desert bitterbrush 2 241 Ros Rosa californica California wild rose 2 242 Ros Rosa woodsii ssp. gratissima interior rose JL 6 30 243 Rub Galium angustifolium ssp. angustifolium narrowleaf bedstraw 244 Rub Galium aparine common bedstraw 4 245 Rub Galium bifolium low mountain bedstraw 3 246 Rub Galium hallii nodding bedstraw 1 99 247 Rub Galium johnstonii Johnston's bedstraw 4 99 248 Sal Populus fremontii ssp. fremontii Fremont cottonwood 1 249 Sal Salix laevigata red willow JL 2 99 250 Sal Salix lasiolepis arroyo willow JL 3 1 251 Sap Acer macrophyllum bigleaf maple 2 252 Sax Lithophragma tenellum slender woodland star 1 253 Scr Limosella acaulis stemless mudwort JL 9 99 254 Sol Lycium andersonii Anderson's boxthorn 1 255 Sol Nicotiana attenuata coyote tobacco JL 1 1 256 Sol Solanum umbelliferum blue-witch nightshade 3 257 Sol Solanum xanti purple nightshade 2 20 258 Ver Verbena lasiostachys var. lasiostachys western vervain JL 4 30 259 Vio Viola purpurea ssp. mohavensis Mojave goosefoot violet 1 260 Vio Viola purpurea ssp. quercetorum goosefoot yellow violet 261 Vis Arceuthobium campylopodum pine dwarf-mistletoe 1 99 262 Vis Phoradendron bolleanum fir mistletoe 2 40 263 Vis Phoradendron juniperinum mistletoe 1 264 Vis Phoradendron serotinum ssp. tomentosum oak mistletoe 2 40 Monocots 265 Aga Hesperoyucca whipplei chaparral yucca 20 266 All Allium fimbriatum var. fimbriatum fringed onion 4 267 All Allium monticola San Bernardino Mountain onion 268 Cyp Carex alma sturdy sedge 1 269 Cyp Carex fracta fragile sheath sedge ~5 270 Cyp Carex multicaulis forest sedge 3 271 Cyp Carex subfusca brown sedge JL 15 272 Cyp Eleocharis acicularis var. acicularis needle spikerush JL 2 99 273 Cyp Eleocharis macrostachya common spikerush 2 274 Cyp Eleocharis parishii Parish's spikerush JL 7 99 275 Cyp Schoenoplectus acutus var. occidentalis common tule JL 5 276 Jun Juncus balticus ssp. ater wire rush 3 277 Jun Juncus bufonius toad rush 1 278 Jun Juncus covillei Coville's rush 279 Jun Juncus mexicanus Mexican rush JL 7 99 280 Jun Juncus rugulosus wrinkled rush 281 Jun Juncus saximontanus Rocky Mountain rush 1 282 Lil Calochortus invenustus plain mariposa lily 1 4 283 Lil Fritillaria pinetorum pine-woods fritillary 3 284 Mel Veratrum californicum var. californicum California corn lily 285 Poa Agrostis exarata spike bentgrass JL 2 99 286 Poa Agrostis stolonifera *creeping bentgrass JL 3 10 287 Poa Alopecurus pratensis *meadow foxtail 2 288 Poa Bromus carinatus var. carinatus California brome 5 5 289 Poa Bromus carinatus var. marginatus Mountain brome 290 Poa Bromus hallii Hall's brome 20 291 Poa Bromus tectorum *downy brome 99 292 Poa Cynodon dactylon *Bermuda grass JL 1 293 Poa Dactylis glomerata *orchard-grass 2 294 Poa Elymus elymoides squirreltail 3 99 295 Poa Elymus glaucus ssp. glaucus blue wildrye 1 296 Poa Elymus trachycaulus ssp. trachycaulus slender wheatgrass 297 Poa Elymus triticoides creeping wild rye 3 298 Poa Festuca perennis *English rye-grass 2 299 Poa Festuca rubra red fescue 1 300 Poa Festuca temulenta *darnel 1 301 Poa Hordeum jubatum ssp. jubatum squirreltail barley 1 302 Poa Hordeum murinum *foxtail barley 2 303 Poa Hordeum vulgare *cultivated barley 304 Poa Melica stricta rock melica 7 5 305 Poa Poa annua *annual blue grass 2 306 Poa Poa bulbosa ssp. vivipara *bulbous blue grass 1 307 Poa Poa pratensis *Kentucky blue grass 2 308 Poa Poa secunda ssp. juncifolia rush blue grass 309 Poa Poa secunda ssp. secunda one-sided bluegrass 4 99 310 Poa Polypogon monspeliensis *rabbits-foot grass JL 3 99 311 Poa Polypogon viridis *green bentgrass 1 312 Poa Sorghum bicolor *sorghum 2 313 Poa Stipa occidentalis western needlegrass 5 314 Poa Stipa occidentalis var. californica California needlegrass 315 Poa Stipa occidentalis var. occidentalis western needlegrass 2 316 Poa Stipa occidentalis var. pubescens Elmer's needlegrass 2 317 Poa Stipa parishii var. parishii Parish's needlegrass 2 16 318 Poa Stipa speciosa desert needlegrass 10 319 Poa Triticum aestivum *common wheat 1 320 Pot Potamogeton crispus *crispate-leaved pondweed JL 6 10 321 Pot Potamogeton foliosus ssp. foliosus leafy pondweed 3 322 Pot Potamogeton illinoensis shining pondweed 1 323 Pot Stuckenia pectinata fennel-leaved pondweed JL 5 10 324 The Dichelostemma capitatum ssp. capitatum blue dicks 325 The Muilla maritima muilla 2 326 Typ Typha domingensis southern cattail JL 2 99 327 Zan Zannichellia palustris horned pondweed 1
Voucher data provided by the participants of the Consortium of California Herbaria (ucjeps.berkeley.edu/consortium/) on 4 September 2015.
We thank Jane Strong for finding the information about the origin of Jackson Lake.
We thank Landy Figueroa for help with the 5 September 2015 survey.