128 Flora of the Palouse Region 



icelled, 6-8 mm. long, with narrow wings: oil-tubes large, solitary between 

 the ribs, 4-6 on the inner side. Bluffs of Snake River in stony soil. The 

 commonest species; used as food by the Indians. 



L. ambiguum C. & R. Glabrous, 10-16 cm. tall, the stems usually leafy: 

 tubers globose or more commonly fusiform: leaves 1-2, pinnately compound, 

 the ultimate segments linear, 1-5 cm. long: umbels unequally 8-18-rayed: 

 flowers yellow: fruit linear, narrow, 6-8 mm. long, on pedicels about as long. 

 Stony soil, common. 



L. gTayi C. & R. Glabrous and somewhat glaucous, the peduncles 8-40 

 cm. high: leaves decompound, the ultimate segments very numerous, short, 

 filiform: umbel 6-16-rayed: flowers yellow; fruit oblong, 8-16 mm. long, 

 glabrous. Common in springy gravelly places. The whole plant is very 

 ill-smelling. 



L. triternatum C. & R. Peduncles 30-70 cm. tall: leaves bipinnate or 

 triternate, puberulent; leaflets linear-lanceolate, 5-15 cm. long: umbel un- 

 equally 5-18-rayed, the rays 1-5 cm. long: fruit oblong, glabrous, 6-12 mm. 

 long: oil-tubes large, solitary between the ribs; two on the inner side. Low 

 meadows, common. 



209. PTERYXIA. 



Acaulescent or nearly so, clothed at the base by the persistent 

 leaf-sheaths: leaves bright green or somewhat pale, clustered at 

 the base, with main divisions ternate, then pinnately finely-dis- 

 sected into short linear segments: involucre mostly none: invol- 

 ucels of narrow bractlets: flowers yellow: calyx-teeth evident: fruit 

 oblong to orbicular, glabrous: carpel usually strongly flattened 

 dorsally, with wings: stylopodium wanting: oil-tubes several in 

 the intervals: seed-face plane or with a shallow and broad cavity. 



P. foeniculaceum Nutt. Rootstock much branched, bearing numerous 

 stems 30-50 cm. tall: leaves pinnately decompound, very finely dissected, 

 glabrous, the ultimate segments linear, 2-4 mm. long: fruit oblong, 6-8 mm. 

 long, the wings not as broad as the body, plane. In rock crevices on the 

 banks of Snake River. 



210. LEPTOTAENIA. 



Usually tall or stout, glabrous, nearly acaulescent: roots thick, 

 fusiform, often very large: leaves usually large, pinnately decom- 

 pound: involucre of few bracts or none: iuvolucels of numerous 

 small bractlets: flowers yellow or purple: calyx-teeth obsolete or 

 sometimes evident: stylopodium wanting: fruit flattened dorsally, 

 oblong-elliptical, glabrous: carpel with dorsal and intermediate 

 ribs filiform or obscure: lateral wings very thick and corky: com- 

 missural face with a prominent central longitudinal ridge left after 

 separation from the carpophore: oil-tubes 3-6 in the intervals, 4-6 

 on the commissural side, mostly small, sometimes obsolete: seeds 

 very flat, with plane or slightly concave face. 



