Flora of Idyllwild Park, San Jacinto Mountains

Fig. 1. Lilly Creek in Idyllwild Park, looking downstream just below beginning of steep portion (see text below). This location is just southwest of the Nature Center. Click on the picture for a larger version.

Fieldwork Dates
Floral Regions
Species Checklist
Notes on Some Species

Fig. 2. The flora of Idyllwild Park contains flowers large and small. Note the fingers for scale in the upper pictures, and the pine needles, branches and one incense-cedar twig for scale in the linked version of the lower picture. Click on the pictures for larger versions.
  • Upper left: the almost-unnoticeable teeny-tiny 3 mm (0.1 inch) flower of Parikh's threadstem, Nemacladus parikhiae, a species only described in 2020.

  • Upper right: the large showy flower of lemon lily, Lilium parryi, ~12 cm (5 inches) across, the probable namesake of Lilly Creek. (Picture from Tahquitz Valley since we do not yet have a picture of a lemon lily flower from Idyllwild Park.)

  • Lower: a field of flowers of volcanic gilia, Gilia ochroleuca ssp. exilis, and Palomar monkeyflower, Mimulus diffusus (called M. palmeri in the Jepson Manual), covering an area.
See Michael Charters' Field Trips Photo Gallery: Idyllwild County Park, San Jacinto Mountains, June 2010 for other pictures of flowers from Idyllwild Park.


Idyllwild Park, a Riverside County Park, is located on the west side of Idyllwild. The Park contains a Nature Center on the north side, and a campground on the south side. Day use fees of $3 per adult, $2 per child and $1 per dog are charged.

The Park is roughly one mile long in the north-south direction at its maximum extent, and one half mile long in the east-west direction at its maximum extent. Its shape is roughly rectangular, with a rectangular piece missing on its northwest corner and a triangular piece missing on its southeast corner, with a total area of 202 acres.

Lilly Creek is the main feature of the western part of the Park, essentially forming the western boundary in the north Park and cutting a steep and deep gorge through the south Park as erosion has proceeded upstream from Strawberry Creek. There is over 560 feet of relief from the bottom of Lilly Creek to the top of the knolls above its banks (5200 feet elevation to over 5760 feet).

The USGS Topo Map uses the name Lilly Creek, although it is given as Lily Creek in other sources. The origin of the name is unknown. But since lemon lilies grow in the creek, it is probable that is the origin of the name. Historic references often spell lily as lillies, so the difference in the spelling is not significant.

Idyllwild Creek is the main topographic feature of the eastern and southeastern sides of the park, although most of the northern part of the creek is on private property to the east. The name Idyllwild Creek appears on a local Idyllwild map, but not on the USGS Topographic Map. Idyllwild Creek has a steep western bank extending to Idyllwild Park, and a gentle eastern bank that is essentially a relatively minor feature in Strawberry Creek Valley. Because of the latter, Idyllwild Creek is flatter in elevation profile along its course than Lilly Creek. Idyllwild Creek forms the southeastern boundary of the park and joins Lilly Creek near the southern end of the Park.

The topography of the Park is shown in the Google Earth image in Fig. 3:

Fig. 3. Google Earth View of Idyllwild Park (approximately the shaded green area) looking northwest. The gorge of Lilly Creek is visible in the center, with the campground road contouring up Lilly Creek to cross the Creek. Lilly Creek has created the steep slopes in the southern half of the park. In contrast, the northern half of the park is much flatter. The steep western bank of Idyllwild Creek is mostly to the east of the Park. It is probably not a coincidence that the meadow visible just above the confluence of Lilly and Idyllwild creeks is located there, due to the presumed-higher water table in that area. Click on the picture for a larger unlabeled version.

The elevation profile of Lilly Creek in Idyllwild Park confirms what is seen in Fig. 3. The erosional nick point, shown by the yellow circle in the middle of the profile, occurs just southwest of the Nature Center, at the location shown in Fig. 1. Above that, the creek elevation profile has a constant slope of about 450 feet per mile. Below that the creek has an elevation profile of about 1200 feet per mile until it levels out in the flattish Strawberry Creek area.

Idyllwild Park has a rich vascular-plant flora due to its many different habitats resulting from its topography, and the fairly well-watered Lilly Creek, at least before it was dammed at Foster Lake with upstream diversions for the Idyllwild Water District.

Fieldwork Dates

Our main plant surveys occurred on all-day trips on 15, 21 and 25 June 2010, and 20 November 2012, by the following people:

Table 1. Major floral surveys of Idyllwild Park

DateSurveyed Area of ParkParticipants
15 June 2010Northwest, mostly on trailTom Chester, Dave Stith and Kay Madore
21 June 2010Northwest, mostly in Lilly CreekTom Chester, Dave Stith and Michael Charters
25 June 2010Southwest, mostly on trail, and NortheastTom Chester, Dave Stith and Michael Charters
20 November 2012Southeast and NortheastTom Chester and Dave Stith

On each survey, every species encountered was recorded, with its first location recorded by GPS. Abundances were estimated for each species at the end of each survey, by estimating the minimum number of plants we saw along our entire survey up to a maximum of 99 plants.

In addition:

Floral Regions

Our surveys showed dramatic differences in the flora between different areas of the park, so we decided to present the flora separately for three different areas of the park. Our division is shown in Fig. 4, which also shows the hiking trails of the Park. As is almost always the case, boundaries between areas are sometimes somewhat arbitrary.

Fig. 4. Map showing Idyllwild Park, its hiking trails, and division into three floral areas (larger version). Base map from Riverside County Parks

The Southwest area has the clearest delineation, being the only part of Idyllwild Park significantly west of Lilly Creek, with a large area of chaparral plants not present in the rest of the Park. Its boundary with the southeast section is taken to be between the Hillside Trail and the Campground Road.

The Southeast area has extensive flattish moist areas not present in the rest of the Park; the only meadow in the Park; significant human disturbance from the 88 site campground; and borders an extensively-developed residential area. Its northern boundary is taken to be approximately along the top of the steep area to the north. This roughly corresponds to the northern boundary of the southwest section. Trails from the Nature Center that lead to the campground allow a fairly clear delineation on the north, except along the Perimeter Trail. Fortunately, the flora doesn't vary much in that section of the Perimeter Trail, so it makes little difference exactly where the boundary is placed.

The southeast portion has south-facing slopes similar to those of the southwest portion.

The North area is distinctive due to its terrain being above the erosional nick point, and hence not as steep as in the other two sections. Probably as a result of its gentler topography, it is covered by pine forest with no significant chaparral component. It contains the upper portion of Lilly Creek, which has a flatter elevation profile in the north.

The routes we have surveyed as of 24 November 2012, along with the GPS points where the first occurrence of species were recorded, are shown in this map (The GPS points shown on the north side of State Route 243 were not used for the Park Flora.) Although our surveys were not done with these divisions into flora areas in mind, our surveys were perhaps not-coincidentally usually confined to one area.

A few surveys crossed boundaries of the floral areas. For those, it was straightforward to use the GPS locations to assign the first location of species to floral areas. However, plant abundance estimates from those surveys could not be ex post facto separated into the floral areas.

Another effect from surveys that crossed boundaries is a possible loss of completeness in the checklist for the second floral area traversed. This occurs when species are present in both floral areas, since those species would be recorded only from their first location, which would be in the first floral area traversed. Fortunately, we have enough surveys beginning in each area that this loss of completeness is probably not high.

Now that we have the floral areas defined, future surveys can produce better abundance estimates and species lists for each area.

Species Checklist

The following is the latest plant checklist for the park from all surveys to 21 September 2020. One species, Orobanche fasciculata (= Aphyllon fasciculatum), came from an iNaturalist observation, and might in fact be an undescribed species, since its flowers are white, not yellow.

We would have included vouchers from Idyllwild Park, but there are no vouchers online that we can be certain have come from the Park itself. There are no online vouchers as of 29 November 2012 whose locality is Idyllwild Park. There are many vouchers with a locality of Idyllwild; we have collected those separately in a Voucher Flora of the Idyllwild Area. However, some of those vouchers are not in fact even from Idyllwild itself, since vouchers often just list the nearest city within 20 miles or even more.

Basic information about the checklist presentation and links:

Three species have qualifiers given in front of the scientific name, indicating that the species determination is not 100%. Notes on some of those species are given in the next section.

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

The three columns under the header #Plants give a minimum estimate of the number of plants we saw along our entire survey in each area (up to a maximum of 99 plants). The southwest area (SW) is presented first, since its flora is significantly different from the other two areas, being dominated by chaparral. The other two areas, the north half of the park (N) and the southeast part of the park (SE), have significant riparian areas and are dominated by the pine forest.

For photographs of many of the species from here, see:

This checklist, the version as of 9 March 2021, is also in PlantID.net (except for one species, Nemacladus parikhiae). The list there allows different displays of this checklist, including an illustrated one, and allows searches on some plant characteristics; see Information about PlantID.net.

The PlantID.net platform provides the following information about the lifeforms of the species on this checklist. It contains:

Update on 4 July 2021: Deborah Burroughs found three to five Garrya flavescens plants on the south side of the small peak that is immediately south/southwest of the Visitor Center. This will be added to the checklist the next time it is updated.

Version for printing, without other text on this page: html (8 pages) or pdf Clickbook booklet (2 double-sided pages). (See printing instructions for an explanation of these options)

#FamilScientific Name
Link goes to the Jepson eFlora
(*)Common Name
Link goes to Calphotos
# Plants
1DennsPteridium aquilinum var. pubescensbracken9990
2EquisEquisetum arvensefield horsetail10
3EquisEquisetum laevigatumsmooth scouring rush99
4PteriCheilanthes covilleibeady lipfern5
5PteriPellaea mucronata var. mucronatabird's-foot fern152
6WoodsCystopteris fragilisbrittle bladder fern1
7CupreCalocedrus decurrensincense-cedar999980
8Cupre~Hesperocyparis stephensoniiStephenson cypress10
9PinacAbies concolorwhite fir22
10PinacPinus coulteriCoulter pine503099
11PinacPinus jeffreyiJeffrey pine171
12PinacPinus lambertianasugar pine104020
13PinacPinus ponderosa var. pacificaponderosa pine69999
14LauraUmbellularia californicaCalifornia bay10
15AdoxaSambucus nigra ssp. caeruleablue elderberry2
16AnacaRhus aromaticabasketbush30
17ApiacTauschia parishiiParish's tauschia5050
18ApocyAsclepias californicaCalifornia milkweed8
19ApocyAsclepias eriocarpaIndian milkweed802535
20ApocyVinca major*greater periwinkle299
21AsterAchillea millefoliumyarrow205020
22AsterAgoseris retrorsaspear-leaved mountain dandelion99299
23AsterAmbrosia acanthicarpabur-ragweed252
24AsterArtemisia douglasianamugwort9999
25AsterArtemisia dracunculuswild tarragon135
26AsterArtemisia ludoviciana ssp. incomptamountain mugwort52030
27AsterArtemisia tridentatabig sagebrush7
28AsterCirsium occidentale var. californicumCalifornia thistle1011
29AsterCirsium vulgare*bull thistle25
30AsterCorethrogyne filaginifoliaCalifornia-aster22099
31AsterEricameria cuneata var. cuneatarock goldenbush1
32AsterEricameria nauseosa var. bernardinaSan Bernardino rubber rabbitbrush18
33AsterEricameria pinifoliapine goldenbush1
34AsterErigeron foliosus var. foliosusleafy daisy999950
35AsterEriophyllum confertiflorum var. confertiflorumgolden yarrow501099
36AsterGnaphalium palustrewestern marsh cudweed99
37AsterHelianthus californicusCalifornia sunflower47
38AsterHemizonella minimadwarf madia99
39AsterHeterotheca sessiliflora ssp. echioidesbristly goldenaster1
40AsterHulsea vestita ssp. callicarphabeautiful hulsea2052
41AsterLactuca serriola*prickly lettuce3
42AsterLessingia glandulifera var. glanduliferasticky lessingia99
43AsterMadia gracilisslender madia20
44AsterMalacothrix clevelandiiannual malacothrix1
45AsterPentachaeta aureagolden daisy9999
46AsterPseudognaphalium californicumCalifornia everlasting11
47AsterPseudognaphalium thermaleslender everlasting109999
48AsterRafinesquia californicaCalifornia chicory5
49AsterSolidago velutina ssp. californicagoldenrod509999
50AsterSonchus asper ssp. asper*prickly sow thistle1
51AsterSonchus oleraceus*sow thistle2
52AsterStephanomeria exigua ssp. deaneislender wreathplant1
53AsterSymphyotrichum defoliatumSan Bernardino aster99
54AsterTanacetum parthenium*feverfew9999
55AsterTragopogon dubius*yellow salsify7
56AsterUropappus lindleyisilver puffs205
57BetulAlnus rhombifoliawhite alder2015
58BoragCryptantha affiniscommon cryptantha510
59BoragCryptantha micrantha var. lepidamountain red-root cryptantha999999
60BoragCryptantha muricata var. jonesiiJones' prickly-nut cryptantha9920
61BoragCryptantha simulanspine cryptantha199
62BoragPhacelia imbricata var. patulaimbricate phacelia99
63BoragPhacelia minorwild canterbury bells17
64BoragPlagiobothrys collinus var. fulvescensCalifornia popcorn flower5
65BoragPlagiobothrys collinus var. ursinusBear Valley popcorn flower30
66BoragPlagiobothrys tenellusslender popcorn flower9999
67BrassArabidopsis thaliana*Mouse-ear cress50
68BrassBoechera californicaCalifornia elegant rock-cress509950
69BrassCardamine hirsuta*hairy toothwort20
70BrassDraba verna*spring draba9999
71BrassErysimum capitatum var. capitatumwestern wallflower17
72BrassHirschfeldia incana*shortpod mustard99
73BrassLepidium virginicum ssp. menziesiiwild pepper-grass99
74BrassRorippa curvisiliquacurvepod yellow-cress2
75BrassSisymbrium altissimum*tumble-mustard599
76BrassThysanocarpus curvipes ssp. curvipesfringe-pod5
77CampaHeterocodon rariflorumfew-flowered heterocodon99
78CampaNemacladus longiflorus var. longiflorusthread plant4099
79CampaNemacladus parikhiaeParikh's threadstem99
80CapriLonicera subspicata var. denudatasouthern honeysuckle997065
81CaryoCerastium fontanum ssp. vulgare*perennial mouse-ear chickweed220
82CaryoLychnis coronaria*rose campion51
83CaryoSilene verecundawhite catch-fly199
84CaryoSpergularia rubra*red sandspurry20
85CaryoStellaria media*common chickweed10
86ConvoCalystegia occidentalis ssp. fulcratawestern morning-glory30
87DatisDatisca glomerataDurango root60
88DipsaDipsacus sativus*Fuller's teasel1
89EricaArctostaphylos glandulosaEastwood manzanita40
90EricaArctostaphylos pringlei ssp. drupaceapink-bracted manzanita999999
91EricaArctostaphylos pungensMexican manzanita210
92EricaChimaphila menziesiilittle prince's pine25
93EricaRhododendron occidentalewestern azalea6030
94EricaSarcodes sanguineasnow-plant218
95EuphoEuphorbia luridawoodland spurge1
96FabacAcmispon americanus var. americanusSpanish clover99
97FabacAcmispon heermannii var. heermanniisilky lotus505010
98FabacAcmispon nevadensis var. nevadensisSierra Nevada lotus301
99FabacAcmispon strigosusstrigose lotus509999
100FabacAstragalus douglasii var. parishiiParish' Jacumba milk-vetch109940
101FabacHosackia crassifolia var. crassifoliabroad-leaved lotus450
102FabacLathyrus latifolius*perennial sweet pea1
103FabacLathyrus vestitus var. vestituswild sweetpea1099
104FabacLupinus bicolordwarf lupine3020
105FabacLupinus concinnus ssp. optatusshowy bajada lupine59970
106FabacLupinus excubitus var. austromontanusmountain grape-soda lupine999935
107FabacLupinus formosuswestern lupine995
108FabacLupinus latifolius var. parishiiParish's lupine10
109Fabac~Melilotus indicus*sourclover1
110FabacTrifolium microcephalumsmall-head field clover9999
111FabacTrifolium monanthum ssp. grantianummountain carpet clover5
112FabacTrifolium variegatumvariegated clover9930
113FabacTrifolium willdenoviitomcat clover99995
114FagacQuercus chrysolepiscanyon live oak509999
115FagacQuercus kelloggiiCalifornia black oak107055
116FagacQuercus wislizeni var. frutescensinterior live oak9999
117FagacQuercus Xmorehusoracle oak114
118GentiFrasera parryiParry's green-gentian169
119GeranErodium cicutarium*redstem filaree99
120GrossRibes nevadensemountain pink currant8060
121HyperHypericum scouleriScouler's St. Johnswort10
122LamiaMentha spicata*spearmint20
123LamiaMonardella breweri ssp. lanceolatamustang mint501010
124LamiaScutellaria siphocampyloidescurve-flowered skullcap9910
125LamiaStachys rigidarigid hedge-nettle9999
126LamiaTrichostema austromontanum ssp. austromontanumsouthern bluecurls99
127LoasaMentzelia dispersascattered blazing star10
128MalvaSidalcea sparsifoliacheckerbloom20
129MontiCalyptridium monandrumsand cress30103
130MontiClaytonia parviflora ssp. utahensisnarrow-leaved miner's lettuce220
131MontiClaytonia parviflora ssp. viridisgreen miner's lettuce309999
132MontiClaytonia rubra ssp. rubrared-stemmed miner's lettuce9940
133OnagrCamissonia strigulosastrigose suncup2
134OnagrCamissoniopsis confusaSan Bernardino suncup30399
135OnagrClarkia rhomboideadiamond-petaled clarkia109999
136OnagrEpilobium brachycarpumautumn willowweed5
137OnagrEpilobium canum ssp. latifoliummountain California-fuchsia183045
138OnagrEpilobium ciliatum ssp. ciliatumwillowherb9999
139OnagrEpilobium densiflorumspike primrose10
140OnagrEpilobium glaberrimum ssp. glaberrimumglaucus willowherb15
141OnagrGayophytum heterozygumzig-zag gayophytum50
142OnagrGayophytum oligospermumpinegrove groundsmoke15030
143OnagrOenothera elata ssp. hirsutissimaHooker's evening-primrose30
144OrobaCastilleja applegatei ssp. martiniiMartin's paintbrush1020
145OrobaCastilleja minor ssp. spiralislesser paintbrush99
146OrobaCordylanthus rigidus ssp. setigerbristly bird's beak9999
147OrobaOrobanche fasciculataclustered broomrapeiN
148PhrymMimulus aurantiacus var. pubescenshairy bush monkeyflower2023
149PhrymMimulus brevipeswide-throated yellow monkeyflower992
150PhrymMimulus cardinalisscarlet monkeyflower70
151PhrymMimulus diffususPalomar monkeyflower9999
152PhrymMimulus floribundusfloriferous monkeyflower5099
153PhrymMimulus fremontii var. fremontiiFremont's monkeyflower9950
154PhrymMimulus guttatuscommon monkeyflower99
155PhrymMimulus pilosusfalse monkeyflower9099
156PlantAntirrhinum coulterianumCoulter's snapdragon15
157PlantKeckiella ternata var. ternatawhorledleaf penstemon99207
158PlantPenstemon centranthifoliusscarlet bugler502075
159PlantPenstemon labrosusSan Gabriel beardtongue26010
160PlantVeronica americanaAmerican speedwell99
161PlataPlatanus racemosawestern sycamore1
162PolemAllophyllum glutinosumsticky false-gilia10
163PolemCollomia grandifloralarge-flowered collomia61
164PolemEriastrum sapphirinumsapphire woolly-star99
165PolemGilia capitata ssp. abrotanifoliaglobe giliax
166PolemGilia diegensiscoastal gilia4230
167PolemGilia ochroleuca ssp. exilisvolcanic gilia9999
168PolemLeptosiphon ciliatuswhisker-brush109999
169PolemLeptosiphon lemmoniiLemmon's linanthus99
170PolemSaltugilia australissouthern gilia99
171PolemSaltugilia splendens ssp. splendenssplendid gilia4599
172PolygEriogonum apiculatumSan Jacinto buckwheat99
173PolygEriogonum davidsoniiDavidson's buckwheat2
174PolygEriogonum gracile var. incultumslender buckwheat99
175PolygEriogonum molestumpineland buckwheat99
176PolygEriogonum wrightii var. membranaceumWright's buckwheat203040
177PolygPolygonum aviculare ssp. depressum*knotweed1
178PolygRumex acetosella*common sheep sorrel50
179PolygRumex californicuswillow-leaved dock5040
180PolygRumex conglomeratus*whorled dock1
181PolygRumex crispus*curly dock23
182PolygSidotheca trilobatathree-lobed oxytheca99
183RanunAquilegia formosawestern columbine8080
184RanunClematis ligusticifoliavirgin's bower1
185RanunThalictrum fendleri var. fendleriFendler's meadow-rue6060
186RhamnCeanothus leucodermischaparral whitethorn1635
187RhamnCeanothus palmeriPalmer's ceanothus1
188RhamnFrangula californicaCalifornia coffeeberry86
189RhamnRhamnus ilicifoliahollyleaf redberry4
190RosacAdenostoma fasciculatumchamise99
191RosacAmelanchier utahensisUtah service-berry2
192RosacCercocarpus betuloides var. betuloidesbirch-leaf mountain-mahogany996
193RosacDrymocallis glandulosa var. viscidasticky cinquefoil299
194RosacDrymocallis lactea var. lacteaNevada cinquefoil4
195RosacFragaria vescawoodland strawberry9999
196RosacHorkelia clevelandii var. clevelandiiCleveland's horkelia995
197RosacPotentilla gracilis var. fastigiataslender cinquefoil30
198RosacPrunus virginiana var. demissawestern choke-cherry20
199RosacRosa californicaCalifornia wild rose9999
200RubiaGalium angustifolium ssp. angustifoliumnarrowleaf bedstraw157070
201RubiaGalium aparinecommon bedstraw6099
202SalicPopulus fremontii ssp. fremontiiFremont cottonwood10
203SalicSalix gooddingiiblack willow20
204SalicSalix laevigatared willow13
205SalicSalix lasiandra var. lasiandrashining willow11
206SalicSalix lasiolepisarroyo willow1560
207ScropVerbascum thapsus*common mullein12
208UrticUrtica dioica ssp. holosericeastinging nettle9999
209ViolaViola purpurea ssp. quercetorumgoosefoot yellow violet20260
210ViscaArceuthobium campylopodumpine dwarf-mistletoe59999
211ViscaPhoradendron serotinum ssp. tomentosumoak mistletoe2050
212AgavaHesperoyucca whippleichaparral yucca205
213CyperCarex fractafragile sheath sedge99
214CyperCarex multicaulisforest sedge10303
215CyperCarex praegracilisclustered field sedge99
216CyperCarex sentaswamp sedge70
217Cyper~Carex subfuscabrown sedge12
218CyperScirpus microcarpuspanicled bulrush9999
219IridaIris germanica*iris1
220JuncaJuncus bryoidesmoss rush99
221JuncaJuncus bufonius var. occidentaliswestern toad rush99
222JuncaJuncus effusus ssp. austrocalifornicusSonoran rush7090
223JuncaJuncus mexicanusMexican rush20299
224JuncaJuncus oxymerispointed rush99
225LiliaCalochortus palmeri var. munziiSan Jacinto mariposa lily73
226LiliaLilium parryilemon lily30
227OrchiPiperia elongatadense-flowered rein orchid102025
228PoaceAgrostis exarataspike bentgrass520
229PoaceAgrostis pallensseashore bentgrass350
230PoaceAgrostis scabrarough bentgrass5
231PoaceBromus carinatus var. carinatusCalifornia brome1099
232PoaceBromus diandrus*ripgut brome11222
233PoaceBromus halliiHall's brome2060
234PoaceBromus madritensis ssp. rubens*red brome1
235PoaceBromus tectorum*downy brome999999
236PoaceCynodon dactylon*Bermuda grass1
237PoaceDeschampsia elongataslender hairgrass36
238PoaceElymus elymoidessquirreltail309990
239PoaceElymus glaucus ssp. glaucusblue wildrye2099
240PoaceElymus hispidus*intermediate wheatgrass1
241PoaceElymus triticoidescreeping wild rye99
242PoaceFestuca microstachyssmall fescue99
243PoaceFestuca myuros*rattail fescue999999
244PoaceHordeum murinum*foxtail barley30
245PoaceKoeleria macranthaJune grass9999
246PoaceMelica imperfectacoast-range melic7516
247PoaceMuhlenbergia rigensdeergrass992070
248PoacePhalaris canariensis*canarygrass2
249PoacePoa bulbosa ssp. vivipara*bulbous blue grass9999
250PoacePoa pratensis ssp. agassizensisKentucky blue grass2099
251PoacePoa secunda ssp. secundaone-sided bluegrass5099
252PoaceSecale cereale*rye51
253PoaceStipa coronatagiant needlegrass30
254PoaceStipa occidentalis var. pubescensElmer's needlegrass530
255ThemiBloomeria croceagoldenstar2060
256ThemiDichelostemma capitatum ssp. capitatumblue dicks50998

Notes on Some Species

Hesperocyparis stephensonii. There are about 10 mature trees that have been planted along the southernmost boundary of the park next to a residential area. Since these are planted trees, they could be Hesperocyparis arizonica, or some hybrid between those two species.

Mimulus diffusus. The Jepson Manual First and Second Editions combined this species with the similar M. palmeri species found in the Transverse Ranges and north. M. diffusus is endemic to the Peninsular Ranges and was considered separate from M. palmeri in Munz 1974. Fraga (2012) demonstrated that there were actually five separate species lumped under the name M. palmeri, and restored M. diffusus as a separate species. Fraga updated the Jepson eFlora treatment in 2018 and restored this species, now under the name of Erythranthe diffusa.

Helianthus californicus. This species is found in only one spot, just below the trail southwest of the Visitor Center where it crosses Lilly Creek. It is short rhizomed, and therefore produces a lot of stems, each spaced a few inches apart. Tom's count was 47 live stems in 2020, not all of which produced flowers.

We thank Deborah Burroughs for the minimum estimate of the number of plants of Umbellularia californica, California bay.

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Copyright © 2010-2020 by Tom Chester, Dave Stith, Bruce Watts, Michael Charters, Keir Morse, Don Rideout, Kay Madore, and Nancy Accola.
Commercial rights reserved. Permission is granted to reproduce any or all of this page for individual or non-profit institutional internal use as long as credit is given to us at this source:
Comments and feedback: Tom Chester
Last update: 11 October 2020; link to PlantID.net added 9 March 2021; links to Riverside County Parks removed on 17 May 2021 since the county broke all the links; update to mention Garrya flavescens on 4 July 2021