Flora of the Palousc Region 



toothed or lobed: heads numerous, short-peduncled: involucre 4-5 mm. high, 

 hirsute: rays pale or violet, very numerous, 5-6 mm. long: pappus double, 

 the inner of a few deciduous bristles, the outer persistent, very short, about 

 as long as the breadth of the akenes: receptacle becoming convex. Sandy 

 banks of Snake River, rare. 



E. strigOSUS Muhl. Annual or biennial, erect, branched above, sparsely 

 hirsute, leafy to the top: lower leaves spatulate-lanceolate, acute, entire or 

 dentate, the blades 5-8 cm. long; upper cauline lanceolate, entire, sessile, 

 smaller: heads loosely corymbed: involucre 3-4 mm. high, glabrous or with 

 a few bristly hairs: rays white, numerous, short, 4-6 mm. long: pappus of 

 the disk-flowers double, the inner of few deciduous bristles, the outer of 

 short persistent scales: ray-flowers with few or no bristles to the pappus. 

 Moist places, uncommon. 



312. PSILOCARPHUS. 



IvOw woolly annuals: leaves entire, mostly opposite: heads small, 

 discoid, many-flowered, in terminal capitate clusters and in the 

 forks of the branches, surrounded by the upper leaves: fertile flow- 

 ers numerous, in several series on the globular chaffy receptacle: 

 pappus none: akene loose in the bladder-like bract, oblong or nar- 

 rower, slightly compressed. 



P. elatior Gray. Erect and simple or more commonly branched from 

 the base and spreading, 5-10 cm. high, loosely white-woolly throughout: 

 leaves lanceolate or linear-spatulate, 1-2 cm. long: heads 6-8 mm. broad, 

 subtended by leaves: fruiting bracts appressed, tomentose: akenes cylindri- 

 cal. Common in low ground near Moscow: very rare near Pullman. 



313. ANTENNARIA. 



Low white-woolly caespitose perennials: leaves alternate, entire: 

 heads small, solitary or corymbose, completely dioecious: recep- 

 tacle naked: staminate flowers with the pappus-bristles thickened 

 or barbellate at the apex; pistillate with the slender pappus- 

 bristles united at base into a ring. 



Densely matted, 2-5 cm. high. A. DIMORPHA. 



Plant 30-50 cm. high: heads in racemes. A. RACEMOSA. 



Plant tufted, 20-30 cm. high: heads corymbose. A. i.i/.ri.oii>KS. 



A. dimorpha Torr. and dray. Densely tufted from stout rootstocks, 2-~, 

 cm. high, silvery canescent throughout: leaves spatulate or oblanceolate, 



mostly acute, 1-2 cm. long: beads solitary, on very short few leaved stems: 

 staminate heads subglobose, 8 mm. high; the involucral scales ovate-lanceo- 

 late, obtuse; pappus not thickened at the tip, minutely toothed: pistillate 

 heads subcylindric, 8-12 mm. high, with broadly lanceolate, mostly acute, 

 involucral scales, glabrous except at base; pappus of long fine smooth bris- 

 tles: akene oblong-linear, pubescent with short hairs, 2-hooked at the sum- 

 mit. Stony soil, bluffs of Snake River, sometimes occupying considerable 

 areas. 



