536 LOASACEAE 



Gravelly soil in the bottoms of rocky caiions, usually in shade, about 500 feet: 

 southwest side of the Colorado Desert. South to Lower California and Sonora. 

 Dec-Apr. 



Loc. — Only one station is known in California, namely. Painted Gorge, 7 miles north of 

 Coyote Wells, southwest side of the Colorado Desert, /. T. Weeks. 



Refs.— Sympetaleia rupestris Gray; Wats. Proc. Am. Acad. 24:50 (1889). Loasella 

 rupestri^ Baill. Bull. Soc. Linn. Paris l:fi50 (1886), type loc. Guaymas, Sonora, Mex. 



4. PETALONYX Gray 



Roufrh-pubescent perennial herbs or low shrubs, with alternate leaves and 

 .small whitish or yellowish flowers. Calyx-limb with 5 linear deciduous lobes as 

 long as ovary. Petals 5, the long claws of the limbs connivent, thus simulating a 

 5-lobed sympetalous corolla. Stamens 5, free, long-exserted. Ovary linear, densely 

 short-hairy, 5-ribbed, 1-celled with one pendulous ovule; style 1, long, exserted; 

 stigma 1. Capsule small, oblong, dehiscing irregularly. — Species 5, southwestern 

 United States and Mexico. (Greek, petalon, leaf, petal, and onyx, claw.) 



Leaf-blades sessile, some or all entire. 



Leaf -blades dull or greenisl*- white, entire or usually some few-toothed; calyx -lobes woolly.... 



1. P. thurberi. 



Leaf -blades green, all entire ; calyx-lobes thinly pilose 2. P. linearis. 



Leaf -blades shining, petioled, dentate 3. P. nitidus. 



1. P. thurberi Gray. Sandpaper Plant. Thickly branched bush, woody at 

 base, 1 to 3 feet high and 2 to 7 feet broad; leaf -blades sessile, narrow-ovate, lance- 

 olate or triangular-lanceolate, mostly entire or some few-toothed toward the base, 

 3 to 8 lines long; flowers greenish-white, in short spikes or heads, these corymbosely 

 disposed; calyx-lobes short, woolly, 1 line long; petals 2 lines long, the blades 

 obovate, obtuse, the claws hairy; stamens 1^ times as long as the corolla; ovary 

 subtended by 2 short bractlets; capsule 1 line long. 



Desert plains and caiions, 1000 to 4000 feet: Inyo Co.; Mohave and Colorado 

 deserts. East to southern Nevada and western Arizona. June- July. 



Locs. — Cottonwood Creek at Owens Lake, Jepson 5093; Halloran Spr., e. Mohave Desert, 

 Jepson 15,799; Painted Canon, Mecca Hills, Jepson 11,686; Palm Canon, Mt. San Jacinto, Jep- 

 son 1399a; McCain Spr., w. Colorado Desert, Jepson 8908. Also near Bakersfield, ace. Ethel M. 

 Eockwell. 



Refs. — Petalonyx thurberi Gray, Mem. Am. Acad. ser. 2, 5:319 (1854), type loc. Gila 

 River Valley, Ariz., Thurber; Torr. Bot. Mex. Bound. 67, pi. 22 (1859) ; Jepson, Man. 653, fig. 

 646 (1925). 



2. P. linearis Greene. Branches many from a woody base, erect, I/2 to 1% 

 feet high; herbage rough; leaf -blades linear to linear-oblong, entire, obtuse or sub- 

 obtuse, sessile, 6 to 12 lines long; flowers congested in close terminal clusters, the 

 bracts ovate or suborbicular with cordate bases; corolla white, 1^/2 to 2 lines long; 

 petals narrowly elliptic, narrowed to a claw nearly as long as the limb, the claw 

 scantily hairy, the limb with a central densely hairy patch on back ; capsule 1 line 

 long, very densely hairy. 



Canons and sandy plains, 100 to 2500 feet : Colorado Desert. South to Lower 

 California. Mar. 



Locs. — Thousand Palms Canon, Jaeger; Rockhouse Canon and Deep Canon (Bull. S. Cal. 

 Acad. 22 :9) ; Bard, ace. C. V. Morton. 



Refs. — ^Petalonyx linearis Greene, Bull. Cal. Acad. 1:188 (1885), type loc. Cedros Isl., 

 Greene; C. V. Morton in Jepson Corr. 23 : 365 ms. 



3. P. nitidus Wats. Stems many from the root-crown, erect or bush-like, 13 

 to 16 inches high; herbage scaberulose; leaf -blades broadly or round-ovate, coarsely 

 few-dentate on each side, 7 to 12 lines long; inflorescence densely paniculate; bracts 

 scaberulose, the margins very densely short-ciliate; corolla 4 lines long. 



