MUSTARD FAMILY 247 



2-lobed, the lobes developed over the valves. Seeds flattened, usually winged. [Greek, 

 meaning twisted flower, in reference to the petals.] 



A genus of about 25 species, native to the western and particularly the southwestern United States. Type 

 species, Streptanthus maculatus Nutt. 



Lower leaves and stems glabrous. 



At least some of the upper leaves auriculate-clasping at the base. 

 Filaments of all the stamens distinct. 



Middle stem leaves broad; pods not sharply reflexed. 



Flowers rarely borne in the axils of the upper leaves; sepals usually setose at apex; petals 

 with narrow blades; stamens nearly equal. 

 Stem leaves not conspicuously crowded on the stem. 



Annual or biennial; pods 1.5-2.5 mm. broad, widely spreading. 



1. 5. campestrxs. 



Perennial; radical leaves tufted at the base; pods erect or ascending, 3-4 mm. broad. 



2. S. cordatus. 



Stem leaves conspicuously crowded, longer than the internodes, ovate-cordate. 



3. 5". barbatus. 



Flowers, at least some of them, borne in the axils of the upper leaves; sepals not setose at 

 apex; petals with broad, flat blades; stamens in 3 unequal pairs. 

 Pods spreading or recurved; common plants of wide distribution. 5. 5". tortuosus. 

 Pods erect; slender plants of the high Sierra Nevada. 6. 5". gracilis. 



Middle stem leaves linear or pinnate with linear divisions; pods sharply reflexed. 



19. S. diversifohus. 



Filaments, of the longest stamens at least, united. 



Seeds distinctly wing-margined all around. 7. S. batrachopus. im 



Seeds not winged, or narrowly margined at the apex. 



Calyx regular or nearly so. 



Pods erect or ascending, straight or more often somewhat incurved. 



8. S. Breweri. 

 Pods spreading or reflexed, more or less strongly recurved. 



Leaves broadly elliptic-ovate to ovate, clasping; seeds often winged at apex. 



9. S. hesperidis. 



Leaves linear or the lowest linear-lanceolate, all but the lowest merely sessile or 

 narrowed at the base. 10. 5". barbiger. 



Calyx irregular. 



Sepals with the three upper connivent, the lower one spreading. 



Sepals purplish to white; pedicels rarely 1 cm. long. 11. 5". gtandulosus. 



Sepals very dark purple; pedicels over 1 cm. long. 12. S. niger. 



Sepals in 2 pairs, the outer suborbicular, the inner ovate, acute. 18. S. polygaloides. 

 None of the leaves auriculate-clasping. 4. S. Howellii. 



Lower leaves and stems more or less setose or hirsute. 



Pods erect, ascending, divaricate or descending; longer stamens connate by their filaments. 

 Stem leaves definitely auriculate-clasping at the base. 



Terminal flowers of the raceme normal or only slightly reduced. 

 Racemes not conspicuously secund. 



Sepals white to purple; pedicels usually not over 1 cm. long. 11.5". glandulosus. 



Sepals very dark purple; pedicels usually over 1 cm. long. 12. S. niger. 



Racemes conspicuously secund, flowers white or yellowish. 13. S. secundus. 



Terminal flowers sterile forming a conspicuous dark-colored tuft composed of numerous elongated 

 sepals. 



Siliques flattened, straight, 5-7 cm. long; seeds winged; leaves pinnatifid. 



14. 5*. insigms. 



Siliques terete, incurved, 1.5-2 cm. long; seeds ovoid, not winged; leaves dentate. _ 



15. 5". callistus. 



Stem leaves cuneate at base; leaves and stems densely hispid. 16. S. hispidus. 



Pods pendent; stamens all distinct. 17. 6". heterophyllus. 



1. Streptanthus campestris S. Wats. Southern Streptanthus. Fig. 1936. 



Streptanthus campestris S. Wats. Proc. Amer. Acad. 25: 125. 1890. 



Annual or biennial, glabrous and glaucous. Basal leaves oblanceolate, broadly rounded, sub- 

 entire or sinuately dentate, more or less setose-ciliate, the blade narrowed to a broad petiole; 

 stem leaves much reduced, lanceolate, sagittate; sepals usually dark purple, about 1 cm. long, 

 bristle-tipped; petals narrow, recurved, purple; filaments distinct; pedicels divergent-ascending, 

 1 . 5-2 cm. long, stout ; pods somewhat flattened, spreading and curved, 7-14 cm. long, 1 . 5-2 mm. 

 broad ; style 1-2 mm. long ; stigma slightly 2-lobed ; seeds winged. 



Arid Transition and Upper Sonoran Zones; Santa Barbara County, California, to Lower California. Type 

 locality: Campo, San Diego County, California. May-June. 



Streptanthus campestris var. bernardinus (Greene) Johnston, Plant World 22: 89. 1919. This is a 

 lower and more slender plant than the typical species, with smaller yellow flowers, recurved somewhat irregular 

 sepals and shorter pedicels. Arid Transition Zone, San Bernardino Mountains, California. 



2. Streptanthus cordatus Nutt. Perennial Streptanthus. Fig. 1937. 



Streptanthus cordatus Nutt. in Torr. & Gray, Fl. N. Amer. 1: 77. 1838. 

 Streptanthus crassifolius Greene, Pittonia 3: 227. 1897. 

 Cartiera multiceps Greene, Leaflets Bot. Obs. 1: 226. 1906. 

 Cartiera leptopetala Greene, Leaflets Bot. Obs. 1: 226. 1906. 



Short-lived perennial, glabrous and glaucous, the stems rather short, mostly unbranched 



