370 COMPOSITE crocidium 



TETRADYMIA 



cle flat, naked, bearing 4 to 6 tubular flowers ; these with narrow 

 cylindric proper tube rather longer than the combined narrow 

 throat and long linear segments. Achenes prismatic, glabrous, 

 surmounted by a rather coarse pappus of firm sorded or brown- 

 ish bristles which are smooth except at the slightly thickened 

 and scabrous apex. '"' 



R. stricta Greene 1. c. Prenanthes stricta Greene. Luina Piperi Robinson. 

 " Perennial, 2 feet high from simple or branching horizontal rootstocks, 

 glabrous, bright green, not glaucous: radical leaves 6-10 inches long, oblong- 

 lanceolate, tapering to a winged petiole, abruptly acuminate, coarsely and 

 repandly dentate; cauline similar but smaller, rather numerous : inflorescence 

 a strict and dense simple raceme 6 inches long; heads erect, their short ped- 

 icels single or in pairs; scales of the cylindrical involucre about 8, purplish 

 and with some white tomentose pubescence, calyculate bracts obscure or none: 

 achenes equally and obtusely 15-ribbecl; pappus pale-fuscous. Dry north- 

 ward slopes, in rocky soil at the limit of trees on Mount Kainier Wash. " 



* * Style-branches of hermaphrodite flowers either truncate or 

 capitellate at tip, which is either naked or penicillate or hirsute and 

 not rarely bearing a short conical or flattened appendage. 



-*-x Involucre lax, usually of much overlapping or unequal bracts. 



82 CROCIDIUM Hook. Fl. i, 335, t. 118. 



Small winter annual herbs with alternate leaves and yellow 

 flowers on scape-like stems in early spring. Heads heterogamous, 

 radiate,' the flowers all fertile. Involucre hemispherical or more 

 open, of 8-12 nearly equal thin-herbaceous bracts. Receptacle 

 conical. Ray-flowers about 12, oblong, with short filiform tube ; 

 disk-flowers with slender tube and campanulate 5-toothed limb 

 Anthers with deltoid-ovate acute tips. Branches of the style short 

 and broad, term inated by large deltoid appendages. Achenes fusi- 

 form-oblong, obscurely 3-5-costate, beset with hyaline oblong pa- 

 pillse, which detaching when wetted throw out a pair of spiral 

 threads. Pappus a single series of equal white barbellate bristles 

 which are very deciduous, commonly wanting in the ray-flowers. 



C. multicaule Hook. 1. c. Flocculent woolly when young, soon most- 

 ly glabrate. producing many simple stems 2-10 inches long from the tuft 

 of obovate or spatulate few-toothed sessile or short-petioled radical leaves ; 

 cauline leaves small, lanceolate to linear: heads solitary, slender-peduncl- 

 ed rather small but showy; bracts of the involucre oblong-ovate. Moist 

 places, Brit. Columbia to California and Idaho. 



■*- -*- Involucre of 4-6 firm and concave close and strongly over- 

 lapping bracts, Jf-9 powered. Shrubs with alternate leaves. 



83 TETRADYMIA DC. Prodr. vi. 440. 



Low and rigid shrubs with alternate or fascicled narrow entire 

 leaves and rather large cymose or clustered heads of yellow flow- 

 ers. Heads homogamous, the flowers all tubular and perfect. 

 Involucre cylindrical to oblong. Receptacle flat. Corollas with 

 elongated tube and lanceolate or linear spreading lobes longer 



