126 Flora of the Palousc Region 



205. CAUCALIS. 



Mostly hispid annuals: leaves pinnately dissected, with very 

 small segments: flowers white: cal} T x-teeth prominent: fruit short, 

 ovate or oblong, flattened laterally: carpel with 5 filiform bristly 

 primary ribs (bristles spreading) and 4 prominently winged secon- 

 dary ones with barbed or hooked prickles: stylopodium thick, 

 conical: oil-tubes solitary in the intervals. 



C. microcarpa Hook. & Arn. Annual, erect, branched, 8-20 cm. tall, 

 more or less hair}': leaves pinnately much dissected, the ultimate segments 

 linear-oblong, 2.5 mm. long: umbels unequally 3-6-rayed: involucre of bracts 

 which resemble the leaves: involucels usually entire: fruit oblong, armed with 

 rows of hooked prickles. Sandy soil, banks of Snake River. 



ANGELICA. 



Stout perennial herbs: leaves ternate, then pinnate, rarely simply 

 pinnate-compound: involucre scanty or none: involucels of small 

 bractlets or none: flowers in large terminal umbels: calyx-teeth 

 mostly obsolete: stylopodium conical: fruit flattened dorsally, ovate 

 or oblong, glabrous or pubescent: calyx-tube prominent, crenulate: 

 carpel with strong ribs, the lateral ribs usually broadly winged, 

 distinct from those of the other carpels, forming a double-winged 

 margin to the fruit: oil-tubes i-several, in the intervals, or indefi- 

 nite; 2-10 on the commisural side: seed face plane or somewhat 

 concave. 



A, lyallii Wats. Stout, 60-150 cm. tall, glabrous or the inflorescence 

 sometimes puberulent: leaves ternate, thin, once or twice pinnate: leaflets 

 ovate or lanceolate, acute, serrate or dentate, 2-10 cm. long: umbel many- 

 rayed: involucre and involucels wanting: fruit oblong, 4-6 mm. 

 long, the lateral wings about as broad as the body. Thatuna Hills, along 

 streams. 



207. HERACLEUM. 



Tall stout perennials: leaves large, ternately compound: invol- 

 ucres deciduous: involucels of numerous bractlets: flowers white, 

 in large many-rayed umbels: calyx-teeth small or obsolete: petals 

 obcordate, the outer ones often dilated and 2 -cleft: stylopodium 

 thick, conical: fruit broadly ovate, very much flattened dorsally, 

 somewhat pubescent: carpel with dorsal and intermediate ribs fili- 

 form; the broad lateral wings contiguous to those of the other car- 

 pel, strongly nerved toward the outer margin: oil-tubes solitary in 

 the intervals, conspicuous, about half as long as the carpel, 2-4 on 

 the commissural side: seed very much flattened dorsally. 



