Flora of the Palouse Region 179 



296. TARAXACUM. 



Acaulescent biennials or perennials, with milky juice: leaves 

 radical, pinnatifid: flowers yellow, on scapes: receptacle flat, naked: 

 involucre of 2 rows of bracts: pappus of copious and white-capil- 

 lary bristles which are not plumose: corollas all .ligulate: akenes 

 oblong or fusiform, angled, about 10-ribbed, attenuate at base, 

 with a long filiform beak at the apex. 



T. officinale Weber. Glabrous or loosely pubescent when young: leaves 

 oblong or oblanceolate, variously pinnatifid, the lobes usually toothed and 

 turned backward, 10-20 cm. long: peduncles 10-30 cm. high: involucre cyl- 

 indric, the inner bracts either linear or linear-lanceolate, the outer similar 

 but shorter and reflexed: heads many-flowered: rays yellow: akenes brown- 

 ish, spinulose above, the pyramidal apex abruptly narrowed into a slender 

 beak, twice as long as the body: pappus white, copious. Abundantly intro- 

 duced. 



297. TROXIMON. 



Acaulescent annuals or perennials, with milky juice: leaves rad- 

 ical, clustered: heads solitary, on scapes: flowers yellow, rarely 

 orange or purplish: bracts of the involucre in a few rows: recep- 

 tacle flat, not chaffy: pappus of copious white capillary bristles, 

 which are not plumose: corollas all ligulate: akenes oblong or lin- 

 ear, terete, 10-ribbed, the apex contracted intoa neck or prolonged 

 into a beak. 



Annual: akenes with a beak longer than the body. T. heterophyli.tm. 

 Perennial. 



Beak of the akene longer than the body. T. grandiflorum. 



Beak of the akene not longer than the body. T. glacccm. 



T- heterophyllum Greene. Annual: leaves linear or lanceolate or ob- 

 lanceolate, entire or variously toothed or pinnatifid, 5-12 cm. long, loosely 

 pubescent: peduncles erect, pubescent or glabrate, 10-30 cm. high: invo- 

 lucre campanulate, 1.5-2 cm. high, the bracts in two series, the outer shorter 

 and usually pubescent: akenes numerous, oblong or fusiform, 10-ribbed or 

 the outer 10-winged, attenuate into a narrow beak, twice or thrice as long: 

 pappus bright white, soft and copious. 



var. kymapleura Greene. Outer akenes or sometimes all of them thick- 

 er, the well-developed wings sinuately folded. 



Common everywhere, the variety probably most abundant. 



T. grandiflomm Nutt. Perennial, loosely pubescent or glabrate: leaves 

 lanceolate or oblanceolate, attenuate-acuminate to obtuse, mostly pinnatifid 

 into numerous lobes, 10-20 cm. long: peduncles stout, 30-60 cm. high: invo- 

 lucre campanulate, tomentose at base, 3-4 cm. high, the bracts in about 3 

 series: akenes fusiform, acutely io-ribbed, 6 mm. long, attenuate into a slen- 

 der beak, 20 mm. long: pappus bright white, soft and capillary, much short- 

 er than the beak. Dry ground, common. 



T. glaUCUm Nutt. Perennial, leaves lanceolate or linear, entire or den- 

 tate or variously pinnatifid, acuminate or attenuate at apex, pale or glau- 



