370 COMPOSITAE 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 sordid or brown- 

 ish bristles which are smooth except at the slightly thickened 

 and scabrous apex." 



R. stricta Greene 1. c. Prenanthes strictq Greene. Luina Pipcri Robin- 

 son. " Perennial, 2 feet high from simple or branching horizontal root- 

 stocks, 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 numer- 

 ous: inflorescence a strict and dense simple raceme 6 inches long; heads 

 erect, their short pedicels single or in pairs; s'-.ales of the cylindrical in- 

 volucre about 8, purplish and with some white tomentose pubescence, 

 calyculate bracts obscure or none : achenes equally and obtusely 15-ribbed ; 

 pappus pale-fuscous. Dry northward slopes, in rocky soil at the limit of 

 trees on Mount Rainier, 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. 



■^ Involucre lax, usually of much overlapping or uneqtMl 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- 

 pillae, 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 J1.-6 firm and concave close and strongly over- 

 lapping bracts, Ji.-9 flowered. 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, 



