298 BRASSICACEAE 



throughout with a dense stellate pubescence; flowering stems 2.5-10 cm. high. Basal leaves 4-8 

 mm. long, oblong, obtuse, entire or sparingly toothed; sepals oblong; petals white, 2-3 mm. 

 long; pedicels ascending, 3-4 mm. long; pods 4-6 mm. long, linear-oblong, obtusish, often 

 twisted, stellate-pubescent ; style scarcely evident. 



Rocky alpine slopes, Hudsonian and Arctic- Alpine Zones; Siskiyou County south in the Sierra Nevada to 

 Tulare County, California. Type locality: Mount Dana, 12,000 feet altitude. June-Sept. 



Draba Breweri var. sublaxa Jepson, Man. Fl. PI. Calif. 444. 1925. Flowering stems 10-15 cm. high; 

 pubescence thinner; lower leaves less crowded, thinner, oblanceolate, 12-18 mm. long; pods 6-8 mm. long, 

 oblong-lanceolate, acute or acuminate. Known only from a single collection on the saddle between Mount Dana 

 and Mount Gibbs, Sierra Nevada, California. 



21. Draba aureola S. Wats. Mount Lassen Draba. Fig. 2085. 



Draba aureola S. Wats. Bot. Calif. 2:430. 1880. 



Low cespitose perennial, stellate-pubescent throughout, with a simple or branched caudex, 

 flowering stems simple or branching above, 5-10 cm. high, leafy to the inflorescence and densely 

 so below. Basal leaves oblanceolate, 12-16 mm. long, obtuse, entire ; stem leaves shorter, oblong ; 

 racemes crowded even in fruit ; sepals glabrous ; petals yellow, 3-4 mm. long ; fruiting pedicels 

 spreading, 4-6 mm. long ; pods broadly oblong, obtuse, 8-10 mm. long, stellate, not twisted ; style 

 stout, 1 mm. long. 



High volcanic peaks, Arctic-Alpine Zone; known from Mount Rainier, Washington, Three Sisters, Ore- 

 son, and Mount Lassen, California. Type locality: Lassen's Peak, California. June- Aug. 



22. Draba corrugata S. Wats. Southern California Draba. Fig. 2086. 



Draba corrugata S. Wats. Bot. Calif. 2:430. 1880. 

 Draba saxosa Davidson, Bull. S. Calif. Acad. 19: 11. 1920. 



Loosely stellate-pubescent perennial with a simple or branched leafy caudex ; flowering stems 

 several, 5-15 cm. high. Basal leaves in a dense tuft, 8-25 mm. long, rarely longer, narrowly 

 obovate to oblanceolate, obtuse, entire ; stem leaves few and much smaller ; sepals pubescent ; 

 petals pale yellow, narrowly linear-spatulate, 2-3 mm. long, retuse ; fruiting pedicels ascending, 

 2-10 mm. long; pods 4-10 mm. long, broadly oblong to lanceolate, acute or obtuse, stellate, cor- 

 rugated and twisted ; style 2 mm. long. 



Dry gravelly or rocky places, Canadian Zones; southern California from the San Gabriel to the San Jacinta 

 Mountains. Type locality: Mount San Gorgonio (Greyback), San Bernardino Mountains. June-Sept. 



41. ATHYSANUS Greene. Bull. Calif. Acad. 1:72. 1885. 



Slender diffuse annual, leafy only near its base, hirsute with spreading forked hairs, 

 Leaves simple, few-toothed. Flowers minute, in very loose elongated unilateral racemes. 

 Pedicels slender, recurved. Sepals equal. Petals linear or often wanting. Stamens 6, 

 equal or nearly so. Ovary 1-celled, 2-ovuled. Silicles orbicular, not winged or margined, 

 1-seeded, indehiscent. [Name Greek, meaning without fringe, in reference to the wing- 

 less pod.] 



A monotypic Pacific Coast genus. 



1. Athysanus pusillus (Hook.) Greene. Dwarf Athysanus. Fig. 2087. 



Thysanocarpus pusillus Hook. Ic. PI. 1 : pi. 42. 1837. 



Thysanocarpus oblongifolius Nutt. in Torr. & Gray, Fl. N. Amer. 1: 118. 1838. 



Athysanus pusillus Greene, Bull. Calif. Acad. 1: 72. 1885. 



Athysanus pusillus var. glabrior S. Wats, in Gray, Syn. Fl. N. Amer. I 1 : 113. 1895. 



Stems very slender, branching from the base, the branches ascending, 10-30 cm. long, uni- 

 laterally racemose from near the base. Leaves few, 5-20 mm. long, ovate-oblong, sparingly 

 toothed; flowers minute, about 1.5 mm. long, often without petals; pod 1-seeded, orbicular, 

 flattened, 1.5-2 mm. long, uncinate-hispid, indehiscent; fruiting pedicels 2-6 mm. long. 



Usually gravelly or sandy soils, Arid Transition and Upper Sonoran Zones; British Columbia and Idaho, 

 south to southern California. Type locality: "Monterey, California." April-July. 



42. HETERODRABA Greene, Bull. Calif. Acad. 1: 71. 1885. 



Low diffuse annual, stellate-hispidulous, branching from the base, the branches very 

 slender, flower-bearing from near the leafy base. Leaves cuneate-obovate to oblanceolate, 

 few-toothed or entire. Flower white in very lax unilateral racemes, minute. Pedicels 

 recurved and distant in fruit. Silicles pubescent, round-oval, compressed, 2-celled, ulti- 

 mately dehiscent. Seeds 6-12, hispidulous; cotyledons accumbent. [Name Greek, mean- 

 ing different, and Draba, the genus to which this species was formerly referred.] 



A monotypic California genus. 



1. Heterodraba unilateralis (M. E. Jones) Greene. Heterodraba. Fig. 2088. 



Draba unilateralis M. E. Jones, Bull. Torrey Club 9: 124. 1882. 

 Heterodraba unilateralis Greene, Bull. Calif. Acad. 1: 72. 1885. 

 Athysanus unilateralis Jepson, Fl. W. Mid. Calif. 224. 1901. 



Branching from the base, the branches very slender, 10-40 cm. long, diffuse, ascending or 

 trailing, rigid or wiry in age, racemose to near the base. Leaves 10-25 mm. long, cuneate- 

 obovate to oblanceolate, sparingly toothed or entire ; flowers 2 mm. long ; pods round-oval, 2-5 

 mm. long, twisted, hispidulous but not uncinate ; fruiting pedicels thick, 1-2 mm. long. 



Hillsides and plains, Upper Sonoran Zone; Oregon to Lower California. Type locality: "About 15 miles 

 south of the California line in Mexico about 60 miles from San Diego." March-April. 



