Gravel Ghost, Atrichoseris platyphylla

Flora of Mecca Hills, Riverside County

yellow-head, Trichoptilium incisum
Pictures taken on 23 March 2011 in Box Canyon.

Procedure For Compiling The Checklist


The Mecca Hills form the eastern boundary of the Coachella Valley portion of the Salton Trough in Riverside County, trending southwest from I-10 east of Palm Springs and Indio to the southern end of Box Canyon Road just east of the town of Mecca.

The checklist presented here is just a start at a flora of the Mecca Hills, compiled from two days of field work in Box Canyon by the authors, and from vouchers, augmented with one species found and photographed by Aaron Schusteff.

The main emphasis of our field work on 23 March 2011 was to study the Nemacladus species here. For more information on those species, see Nemacladus of Box Canyon, Mecca Hills. That page also includes more information about the field work.

The main emphasis of our field work on 2 January 2012 was to survey the large number of species in bloom in a wash area that had received good rain in October 2011, as well as to compile a list of all species in that area. See the list of all the species in bloom then.

Procedure For Compiling The Checklist

Field Surveys

23 March 2011

All authors except Pam Pallette surveyed the four locations shown in Fig. 1 on 23 March 2011:

Fig. 1. Locations surveyed along Box Canyon Road on 23 March 2011. The first three stops were roadside surveys only, surveying only for Nemacladus species. At the fourth stop, Shavers Well, we surveyed for all plant species up about 0.5 miles of a side canyon, shown as the red line.

We had only a single goal of surveying for Nemacladus species at the first three stops. Other plant species were only incidentally noted. At the fourth stop, at Shavers Well, we systematically surveyed for all plant species along the western side of Box Canyon Road, and for 0.5 miles up the wash shown as the red line in Fig. 1.

The systematic survey in the Shavers Well area yielded 87 taxa, of which 74 were previously vouchered and 13 are new records for the flora of this area.

An additional 20 plants were observed in the other stops, of which 16 were vouchered and 4 are new records.

Tommy Stoughton found four additional species in several days of fieldwork within a week or so of our survey, which are noted in the Checklist below as being observed by him. All of those species have been vouchered.

One additional species was observed in this area by Aaron Schusteff, Antirrhinum cyathiferum, known previously in California from only a single other location, in Deep Canyon in the Santa Rosa Mountains. Aaron vouchered it with his photographs (one of seven), since he only saw a single plant.

The total number of observed taxa from all of the above is 112.

2 January 2012

Three of the authors, Tom Chester, Kate Harper and Pam Pallette surveyed the lowermost part of Box Canyon, immediately east of the Aqueduct, on 2 January 2012, since RT Hawke had reported that there were a large number of species in bloom there. We found 50 species in bloom! Overall, we found 77 species, of which 75 were fairly confidently identified.

The rough survey locations, drawn from memory, are shown as the red lines in Fig. 2:

Fig. 2. The red lines show the approximate locations surveyed in extreme lowermost Box Canyon on 2 January 2012.

It was notable that we found young plants of a number of perennial, shrub and tree species. Often there were large number of young plants, many of which seemed to be several years old. In many cases, there were no adults of those species present in this area, indicating that the seeds had washed down to this point from parent plants higher in the wash. Table 1 gives those species.

Table 1. Perennial, Shrub and Tree Species with Young Plants Observed

Acacia greggiiForests of plants that were probably several years old
Ambrosia dumosaMany young plants, possibly two years old
Bebbia juncea var. asperaJust a few young plants
Brandegea bigeloviiLarge number of plants growing at the base of annual Datura discolor plants, as well as in the open, indicating that these were young plants.
Caesalpinia virgataTwo young plants
Datura wrightiiA large number of young plants, probably first year plants
Encelia farinosaMany seedlings
Hymenoclea salsolaHuge numbers of young plants of various ages
Hyptis emoryiSeven seedlings
Larrea tridentataA number of young plants
Mirabilis bigelovii var. retrorsaThree young plants
Psorothamnus spinosusHuge numbers of seedlings, many still in the leafy stage of growth before twigs without leaves grow
Sphaeralcea ambiguaA single seedling
Tiquilia palmeriTwo young plants
Tidestromia oblongifoliaJust a few young plants

Total Species from All Surveys

The total number of observed taxa from both the 23 March 2011 and the 2 January 2012 surveys was 131.


The vouchered species on this checklist come from a search on 22 March 2011 of the Consortium of California Herbaria.

The Consortium records were searched for vouchers with coordinates between 33.68 and 33.55° N. Latitude, and -116.03 and -115.87 E. Longitude.

An additional search was done for any voucher with Box Canyon in its locality field.

These two searches yielded 1,216 vouchers, which contained vouchers from the Box Springs area of Riverside County, and a surprising number of vouchers with erroneous coordinates that were from Mount Pinos in Ventura County, and from the Panamint Mountains in Inyo County. Those vouchers were manually removed via a review of their locality.

The geographic coordinate search also included some vouchers from the north of the Mecca Hills, which were also removed.

The final voucher data set contained 785 taxa, which were from 176 unique sets of collector names. After combining all permutations of names from the top collectors, seven individuals or sets of collectors were each responsible for collecting more than 3.0% of the vouchers. They are given in Table 2.

Table 2. Most prolific Collectors in the Mecca Hills

# Vouchers% VouchersCollector
9912.6%Christopher Davidson
698.8%W. Wisura
374.7%Scott D. White
364.6%M. B. Dunkle
364.6%P. A. Munz, D. D. Keck
314.0%Robert Gustafson
273.4%Marcus E. Jones
785100%All Collectors

Of these 785 vouchers, 11 were determined only to genus and ignored for the checklist. One voucher of Antirrhinum virga, an extreme northern California species, was ignored as being misdetermined. Two vouchers of Phacelia crenulata were ignored, since three subspecies were already present in the voucher list.

This left 771 vouchers of 173 taxa.

Total Checklist

The total checklist contains 202 taxa, 131 from observations and 173 from vouchers.

Checklist for Mecca Hills / Box Canyon Area

The Checklist is sorted first by category - dicots, monocots, and ferns - and then by family and scientific name. The Family and Scientific Name are from the Jepson Manual 1993 First Edition.

The columns titled #Pls gives the minimum number of plants found in our two surveys. LR is the survey in Lowermost Box Canyon. SH is our survey near Shavers Well, along with whether a given species was observed elsewhere by us (indicated by Obs in that column), Tommy Stoughton (Sto), or Aaron Schusteff (Sch).

The column titled #V gives the number of vouchers found for this area.

Voucher locations for any taxon can be obtained by searching the Consortium of California Herbaria for the taxon name.

A few of the voucher species are unlikely to be correctly determined: Rafinesquia californica and Keckiella cordifolia. These have been left in pending examination of those vouchers, since it is remotely possible they exist here.

It is possible that Ditaxis californica is simply a glabrous form of D. neomexicana. However, since vouchers are split equally between the two species, and one of the ten plants we observed on 2 January 2012 was glabrous, we've kept both species in the checklist.

We observed a single annual plant of the Mentzelia affinis, albicaulis, desertorum persuasion, but failed to examine the fruit to get the actual determination. It is listed below under the most commonly vouchered one of those species here, with a question mark after its abundance to indicate the uncertainty in this determination.

Version for printing, without lines and other text on this page: html (7 pages) or pdf Clickbook booklet (2 double-sided pages). (See printing instructions for an explanation of these options)

#FAMScientific Name(*)Common Name#Pls
1Pteridaceae Cheilanthes covilleibeady lipfern  1
2Pteridaceae Cheilanthes parryiwoolly lipfern  2
3Acanthaceae Justicia californicachuparosa 4212
4Amaranthaceae Amaranthus fimbriatusfringed amaranth1  
5Amaranthaceae Tidestromia oblongifoliaArizona honeysweet2524
6Asclepiadaceae Asclepias subulatarush milkweed Obs4
7Asclepiadaceae Sarcostemma cynanchoides ssp. hartwegiiclimbing milkweed  4
8Asclepiadaceae Sarcostemma hirtellumrambling milkweed 504
9Asteraceae Adenophyllum porophylloidesSan Felipe dogweed  2
10Asteraceae Ambrosia dumosaburroweed50203
11Asteraceae Atrichoseris platyphyllagravel-ghost19911
12Asteraceae Baileya pauciradiataColorado Desert marigold  2
13Asteraceae Baileya pleniradiatawoolly marigold  1
14Asteraceae Bebbia juncea var. asperasweetbush105011
15Asteraceae Calycoseris parryiyellow tackstem  2
16Asteraceae Calycoseris wrightiiwhite tackstem  4
17Asteraceae Chaenactis carphoclinia var. carphocliniapebble pincushion505012
18Asteraceae Chaenactis fremontiiFremont pincushion  1
19Asteraceae Chaenactis stevioidesdesert pincushion  1
20Asteraceae Encelia farinosabrittlebush15993
21Asteraceae Geraea canescenshairy desert-sunflower15Obs3
22Asteraceae Hymenoclea salsolacheesebush  6
23Asteraceae Hymenoclea salsola var. pentalepischeesebush  1
24Asteraceae Hymenoclea salsola var. salsolacheesebush99991
25Asteraceae Malacothrix glabratadesert dandelion 103
26Asteraceae Monoptilon bellioidesdesert star15010
27Asteraceae Palafoxia arida var. aridadesert needle99Obs8
28Asteraceae Perityle emoryiEmory's rock-daisy30999
29Asteraceae Peucephyllum schottiipygmy-cedar 107
30Asteraceae Pleurocoronis plurisetaarrow-leaf 507
31Asteraceae Pluchea sericea(?)Arrow-weed(?)1  
32Asteraceae Porophyllum gracileodora  1
33Asteraceae Psathyrotes ramosissimaturtleback Obs8
34Asteraceae Rafinesquia californicaCalifornia chicory  1
35Asteraceae Rafinesquia neomexicanadesert chicory 12
36Asteraceae Senecio mohavensisMojave ragwort 997
37Asteraceae Sonchus oleraceus*sow thistle 5 
38Asteraceae Stephanomeria pauciflora var. pauciflorawire-lettuce 20 
39Asteraceae Trichoptilium incisumyellow-head 5014
40Asteraceae Trixis californica var. californicaCalifornia trixis  7
41Asteraceae Viguiera parishiiParish's viguiera1  
42Asteraceae Xylorhiza cognataMecca-aster  24
43Asteraceae Xylorhiza tortifolia var. tortifoliaMojave-aster  1
44Bignoniaceae Chilopsis linearis ssp. arcuatadesert-willow  4
45Boraginaceae Amsinckia tessellata var. tessellatabristly fiddleneck 1 
46Boraginaceae Cryptantha angustifolianarrow-leaved cryptantha99999
47Boraginaceae Cryptantha barbigerabearded cryptantha 998
48Boraginaceae Cryptantha holopterawinged cryptantha  1
49Boraginaceae Cryptantha maritimaGuadalupe cryptantha25997
50Boraginaceae Cryptantha micranthapurple-root cryptantha  1
51Boraginaceae Cryptantha pterocaryawing-nut cryptantha  2
52Boraginaceae Cryptantha utahensisscented cryptantha  1
53Boraginaceae Pectocarya heterocarpachuckwalla pectocarya  1
54Boraginaceae Pectocarya penicillatacombseed  1
55Boraginaceae Pectocarya platycarpabroad-fruited combseed  2
56Boraginaceae Pectocarya recurvatacurvenut combseed Sto2
57Boraginaceae Tiquilia palmeriPalmer's coldenia2Obs5
58Boraginaceae Tiquilia plicataplicate coldenia15 3
59Brassicaceae Brassica tournefortii*Asian mustard99102
60Brassicaceae Descurainia pinnata ssp. glabrasmooth western tansy-mustard Sto1
61Brassicaceae Dithyrea californicaspectacle-pod  1
62Brassicaceae Lepidium fremontiidesert pepper-grass  2
63Brassicaceae Lepidium lasiocarpum var. lasiocarpumhairy-podded pepper-grass10992
64Brassicaceae Sisymbrium irio*London rocket30  
65Brassicaceae Sisymbrium orientale*Oriental mustard 201
66Cactaceae Opuntia basilaris var. basilarisbeavertail cactus 6 
67Cactaceae Opuntia echinocarpasilver cholla 21
68Cactaceae Opuntia ramosissimapencil cholla 10 
69Campanulaceae Nemacladus glanduliferusglandular nemacladus  1
70Campanulaceae Nemacladus glanduliferus var. glanduliferusglandular nemacladus 5 
71Campanulaceae Nemacladus glanduliferus var. orientaliseastern glandular nemacladus Obs 
72Campanulaceae Nemacladus rubescensdesert nemacladus Obs 
73Campanulaceae Nemacladus tenuis var. aliformisdesert threadplant 302
74Capparaceae Isomeris arboreabladderpod 41
75Caryophyllaceae Achyronychia cooperifrost mat60 6
76Chenopodiaceae Atriplex canescens ssp. canescensfour-wing saltbush7  
77Chenopodiaceae Atriplex hymenelytradesert holly2Obs3
78Chenopodiaceae Atriplex polycarpacattle saltbush20151
79Chenopodiaceae Chenopodium murale*nettle-leaved goosefoot30302
80Chenopodiaceae Salsola sp.*5  
81Cucurbitaceae Brandegea bigeloviidesert star-vine507525
82Cucurbitaceae Cucurbita palmatacoyote melon1  
83Euphorbiaceae Chamaesyce ocellataContura Creek spurge  1
84Euphorbiaceae Chamaesyce parishiiParish's spurge  1
85Euphorbiaceae Chamaesyce pediculiferaCarrizo Mountain spurge  1
86Euphorbiaceae Chamaesyce polycarpasmall-seeded spurge50203
87Euphorbiaceae Chamaesyce setilobastarfish (Yuma) spurge30852
88Euphorbiaceae Croton californicusCalifornia croton Obs2
89Euphorbiaceae Ditaxis californicaCalifornia ditaxis1 3
90Euphorbiaceae Ditaxis lanceolatanarrowleaf ditaxis 507
91Euphorbiaceae Ditaxis neomexicanaNew Mexico ditaxis25 3
92Euphorbiaceae Euphorbia erianthabeetle spurge1  
93Euphorbiaceae Stillingia linearifolialinear-leaved stillingia  1
94Euphorbiaceae Stillingia spinulosaannual stillingia  1
95Fabaceae Acacia greggiicatclaw9913 
96Fabaceae Astragalus aridusannual desert milk-vetch  2
97Fabaceae Astragalus lentiginosus var. coachellaeCoachella Valley milk-vetch  1
98Fabaceae Astragalus sabulonumgravel milk-vetch  1
99Fabaceae Caesalpinia virgatawand holdback189926
100Fabaceae Cercidium floridum ssp. floridumblue palo verde25213
101Fabaceae Dalea mollissilky dalea10 4
102Fabaceae Dalea mollissimadowny dalea  1
103Fabaceae Lotus salsuginosus var. brevivexillusshort-bannered coastal lotus 24
104Fabaceae Lotus strigosusstrigose lotus99107
105Fabaceae Lotus wrangelianusCalifornia lotus  1
106Fabaceae Lupinus arizonicusArizona lupine999916
107Fabaceae Lupinus sparsiflorusCoulter's lupine  2
108Fabaceae Marina parryiParry's marina1Obs4
109Fabaceae Olneya tesotaironwood46312
110Fabaceae Prosopis glandulosa var. torreyanahoney mesquite 103
111Fabaceae Psorothamnus emoryiEmory's indigo-bush8Obs2
112Fabaceae Psorothamnus schottiiindigo bush525
113Fabaceae Psorothamnus spinosussmoke tree993 
114Fouquieriaceae Fouquieria splendens ssp. splendensocotillo 101
115Geraniaceae Erodium cicutarium*redstem filaree202 
116Hydrophyllaceae Emmenanthe penduliflora var. penduliflorawhispering bells 501
117Hydrophyllaceae Eucrypta chrysanthemifoliaeucrypta  1
118Hydrophyllaceae Nama demissum var. demissumpurple mat 208
119Hydrophyllaceae Phacelia campanularia ssp. vasiformisdesert bluebells  1
120Hydrophyllaceae Phacelia crenulata var. ambiguaheliotrope phacelia7999
121Hydrophyllaceae Phacelia crenulata var. crenulataheliotrope phacelia  1
122Hydrophyllaceae Phacelia crenulata var. minutifloralittle-flowered heliotrope phacelia  1
123Hydrophyllaceae Phacelia distanscommon phacelia1107
124Hydrophyllaceae Phacelia pedicellatapedicellate phacelia  1
125Krameriaceae Krameria grayiwhite rhatany  1
126Lamiaceae Hyptis emoryidesert-lavender75013
127Lamiaceae Salvia columbariaechia25993
128Lamiaceae Salvia greataeOrocopia sage  1
129Loasaceae Mentzelia desertorumdesert blazing star 13
130Loasaceae Mentzelia involucratabracted blazing star~19915
131Loasaceae Mentzelia jonesiiJones' blazing star  5
132Loasaceae Mentzelia obscuraPacific blazing star  1
133Loasaceae Petalonyx linearisnarrow-leaf sandpaper-plant  1
134Loasaceae Petalonyx thurberiThurber's sandpaper-plant  1
135Malvaceae Eremalche rotundifoliadesert five-spot 103
136Malvaceae Hibiscus denudatusrock hibiscus 51
137Malvaceae Sphaeralcea ambiguaapricot mallow  3
138Malvaceae Sphaeralcea ambigua var. ambiguaapricot mallow1Obs 
139Nyctaginaceae Abronia villosa var. villosahairy sand-verbena20Obs5
140Nyctaginaceae Allionia incarnatatrailing four o'clock15 5
141Nyctaginaceae Boerhavia wrightiiWright's spiderling30  
142Nyctaginaceae Mirabilis bigelovii var. bigeloviiBigelow's desert four-o'clock 10 
143Nyctaginaceae Mirabilis bigelovii var. retrorsaBigelow's desert four-o'clock331
144Onagraceae Camissonia boothii ssp. condensataBooth's evening primrose426
145Onagraceae Camissonia brevipes ssp. brevipesgolden sun-cup12012
146Onagraceae Camissonia californicaCalifornia suncup  2
147Onagraceae Camissonia cardiophylla ssp. cardiophyllaheartleaf sun-cup502013
148Onagraceae Camissonia claviformis ssp. aurantiacabrown-eyed primrose99115
149Onagraceae Camissonia pallidapale-yellow sun-cup  1
150Onagraceae Camissonia refractanarrow-leaf sun-cup~1999
151Onagraceae Oenothera deltoides ssp. deltoidesdune primrose  1
152Orobanchaceae Orobanche cooperiCooper's broom-rape  3
153Papaveraceae Eschscholzia minutiflora ssp. minutiflorasmall-flowered poppy 999
154Papaveraceae Eschscholzia parishiiParish's poppy 9915
155Plantaginaceae Plantago ovatadesert plantain99207
156Polemoniaceae Eriastrum eremicum ssp. eremicumdesert woolly-star10Obs1
157Polemoniaceae Gilia latifoliabroad-leaf gilia 9911
158Polemoniaceae Gilia stellatastar gilia 25
159Polemoniaceae Langloisia setosissima ssp. setosissimabristly langloisia Obs1
160Polemoniaceae Linanthus bigeloviiBigelow's linanthus Sto1
161Polemoniaceae Linanthus jonesiiJones' linanthus 44
162Polemoniaceae Loeseliastrum matthewsiidesert calico  1
163Polemoniaceae Loeseliastrum schottiiSchott's calico Obs3
164Polygonaceae Chorizanthe brevicornu var. brevicornubrittle spineflower 994
165Polygonaceae Chorizanthe corrugatawrinkled spineflower  7
166Polygonaceae Chorizanthe rigidadevil's spineflower Sto2
167Polygonaceae Eriogonum davidsoniiDavidson's buckwheat  1
168Polygonaceae Eriogonum deflexum var. deflexumflat-topped buckwheat Obs7
169Polygonaceae Eriogonum inflatumdesert trumpet2102
170Polygonaceae Eriogonum thomasiiThomas' buckwheat209917
171Polygonaceae Eriogonum trichopeslittle desert trumpet  3
172Portulacaceae Calandrinia ambiguadesert red maids Obs3
173Portulacaceae Calyptridium monandrumsand cress Obs1
174Resedaceae Oligomeris linifolialineleaf whitepuff11 
175Rhamnaceae Ziziphus obtusifolia var. canescensgraythorn  1
176Rubiaceae Galium stellatum var. eremicumstar-flowered bedstraw  2
177Scrophulariaceae Antirrhinum cyathiferumDeep Canyon snapdragon Sch 
178Scrophulariaceae Antirrhinum filipesdesert twining snapdragon  4
179Scrophulariaceae Keckiella cordifoliaheartleaf penstemon  1
180Scrophulariaceae Mimulus bigelovii var. bigeloviiBigelow's monkeyflower 995
181Scrophulariaceae Mohavea confertifloraghost flower 9913
182Simmondsiaceae Simmondsia chinensisjojoba  1
183Solanaceae Datura discolordesert thornapple30Obs 
184Solanaceae Datura wrightiisacred datura10 2
185Solanaceae Lycium andersoniiAnderson's desert-thorn 3 
186Solanaceae Lycium fremontiiFremont box-thorn  1
187Solanaceae Nicotiana obtusifoliadesert tobacco99107
188Solanaceae Physalis crassifoliathick-leaved ground cherry9959
189Tamaricaceae Tamarix ramosissima*saltcedar75  
190Urticaceae Parietaria hespera var. hesperapellitory  2
191Viscaceae Phoradendron californicumdesert mistletoe 254
192Zygophyllaceae Fagonia laevisCalifornia fagonia  9
193Zygophyllaceae Fagonia pachyacanthasticky fagonia1992
194Zygophyllaceae Larrea tridentatacreosote bush75503
195Arecaceae  * Palm tree species 2  
196Poaceae Aristida adscensionissix-weeks three-awn2206
197Poaceae Bouteloua aristidoides var. aristidoidesneedle grama1 2
198Poaceae Bouteloua barbata var. barbatasix-weeks grama  2
199Poaceae Erioneuron pulchellumfluff grass  1
200Poaceae Muhlenbergia microspermalittleseed muhly  1
201Poaceae Schismus arabicus*Mediterranean grass  2
202Poaceae Schismus barbatus*Mediterranean schismus9999 

We thank Tommy Stoughton for alerting us to blooming Nemacladus in this canyon, which was the origin for this page.

Voucher data provided by the participants of the Consortium of California Herbaria (

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Copyright © 2011 by Tom Chester, Kate Harper, Vince Balch, Mike Crouse, Walt Fidler, Dave Stith and Pam Pallette.
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
Comments and feedback: Tom Chester
Last update: 7 January 2012