l8o UMBELLIFERAE. 



Oil tubes none; tubers often moniliform. C. geyeri. 



Oil tubes present; tuber solitary. 



Tuber large ; oil tubes solitary in the intervals. C. canbyi. 

 Tuber small ; oil tubes several in each interval. C. farinosa. 

 Taller plants, the roots elongate, scarcely tuberous (some- 

 times so in C. ambigua). 

 Involucels conspicuous; flowers white. 



Herbage sparsely tomentose. C. macrocarpa. 



Herbage densely puberulent. C. artemisiarum. 



Involucels small or wanting; flowers yellow. 



Fruit linear; leaves 1 or 2 times pinnate with ultimate 



segments 1-5 cm. long. C. ambigua. 



Fruit oblong; leaves decompound or 2 or 3 times pin- 

 nate with ultimate segments 5-15 cm. long. 

 Leaves much dissected with short segments; wings 



of fruit broad; plant ill-scented. C. grayi. 



Leaves 1-3 times ternate, the segments elongate; 



plants not ill scented. C. triternata. 



Cogswellia cous (Wats.) Jones. Proper stem none; peduncles 8-12 cm. 

 tall; tuber subglobose or elongate; leaves glabrous, bipinnately compound, the 

 ultimate segments oblong, acute, mostly entire; umbel 3-12-rayed, the rays 

 unequal, 1-4 cm. long; flowers yellow; fruit oblong, sparsely puberulent, short- 

 pedicelled, 6-8 mm. long, with narrow wings; oil-tubes large, solitary between 

 the ribs, 4-6 on the inner side. Bluffs of the Snake and Clearwater Rivers 

 and in the Blue Mountains, in stony soil. The principal species used as food 

 by the Indians under the name cause. 



Cogswellia gormani (Howell) Jones. Glabrous or nearly so, the proper 

 stems short or none; peduncles 5-7 cm. tall, ascending or spreading; tubers 

 globose, about 2 cm. in diameter, bearing numerous roots on the under side; 

 leaves bipinnate, the ultimate segments oblong or linear; umbel unequally 

 1-10-rayed; flowers white; anthers purple; fruit ovate, sessile, puberulent, 

 6 mm. long. Abundant in rocky places. 



Cogswellia geyeri (Wats.) Jones. Acaulescent or nearly so; tubers 

 round, deep seated, often several in a series; herbage glabrous; leaves once or 

 twice ternate and then more or less pinnate, the ultimate segments linear and 

 callus-tipped; umbel unequally 8-18-rayed, the numerous lanceolate bractlets 

 of the involucels united; flowers white; fruit oblong, glabrous, 8-10 mm. long, 

 5 mm. broad, the thin wings half as broad as the body; oil tubes none. Common 

 in sandy or gravelly soil about Spokane. 



Cogswellia canbyi (Coult. & Rose) Jones. Proper stem short, mostly 

 underground, arising from a large globose tuber with thick black rind; leaves 

 ternate, then pinnatifid, the ultimate segments small with 3-5 linear lobes; 

 scape 8-20 cm. high, usually reddish; umbel with 5-10 subequal rays; fruits 

 pedicelled, oblong-ovate, glabrous, 8 mm. long; oil tubes solitary in the intervals, 

 2-4 on the inner side. In rocky ground on the lower Clearwater River, Idaho. 



Cogswellia farinosa (Hook.) Jones. Proper stems usually short; peduncles 

 10-30 cm. high; tubers globose, rarely 2 or 3 in a row; leaves once or twice 

 palmate; leaflets linear, 1-8 cm. long, 3-5 together; umbel unequally 5-15- 

 rayed, the rays 2-5 cm. long; flowers white; fruit pedicelled, linear-oblong, 

 glabrous, 6-8 mm. long. Rock ledges on the bluffs of Snake River. 



Cogswellia macrocarpa (Nutt.) Jones. Proper stems short, the peduncles 

 10-40 cm. high, white-pubescent throughout; roots elongate, fusiform; leaves 

 decompound, the ultimate segments ovate or linear, short; umbels 3-20-rayed, 

 the involucels conspicuous, lanceolate; flowers white; fruit oblong, glabrous, 

 6-20 mm. long. On basalt outcroppings, common. 



