436 COMPOSITE. Lygodesmia. 



L. juncea, var. dianthopsis, Eaton, Bot. King Exp. 200, the well-developed and taller form, 

 leafy to the top. Er-ythremia (jrandijlora, Nutt. Traus. Am. Phil. 8oc. vii. 445, dwarf form. 



— Gravelly hills or .slope.s, W. Wyoming (first coll. by Nutlall), Utah about Salt Lake (first 

 coll. by Stansbury), and S. Utah. 



L. aphylla, L)C. 1. c. Stems mo.stly solitary from the root, slender and quite rush-like, 

 2 feet or so high, naked or nearly so, once or twice forked above, and bearing solitai-y long- 

 peduncled heads : leaves rather fleshy, chiefly radical or near the ground, filiform, elongated, 

 entire, or with one or two rare teeth ; upper reduced to minute scales at the forks : involucre 

 (mostly 10-flowered) and rose-colored ligules each two-thirds to three-fourths inch long. — 

 Terr. & Gray, 1. c. ; Chapm. Fl. 251. Prenanthes aphylla, Nutt. Gen. ii. 123 ; Ell. Sk. ii. 261. 

 Erythremia aphylla, Nutt. Trans. Am. Phil. Soc. 1. c. 446. — Dry pine barrens, S. Georgia 

 and Florida ; first coll. by Baldwin. 



Var, Texana, Torr. & Gray, 1. c. Stouter : leaves more numerous, from filiform 

 and usually with 2 or 3 lateral lobes to linear (2 lines broad) and sparingly pinnately lobed, 

 also some smaller leaves on the stem : some Texan specimens nearly like those of Florida. 



— Rocky hills and plains, Texas ; first coll. by Berlandier, Drumiitond, &c. 



§ 2. Diffuse and spinesceiit perenni:il, with flexuous branches not striate-angled : 

 pa^ipus rigidulous, whitish, of unequal bristles. — § Fleiacanthus, Nutt. 



L. spinosa, Nutt. 1. c. Stems slender and rigid, low, much branched from an indurated 

 and matted-woolly base, otherwi.se glabrous : branchlets divergent, spinescent, bearing 

 minute scales in place of leaves and lateral very short-peduncled heads : lower cauline leaves 

 linear, entire, thickish, above soon reduced to scales : involucre 3-5-flowered ; its proper bracts 

 not more numerous, rather loose, lanceolate ; the unequal and more imbricated calyculate 

 ones comparatively broad and large : akenes much shorter than the pappus, not at all nar- 

 rowed upward, 4-5-costate. — Torr. & Gray, 1. c. ; Eaton, Bot. King P^xj). 200 ; Gray, Bot. 

 Calif. 441. — Gravelly hills and plains in the arid district, S. Idaho to S. Nevada and the east- 

 ern borders of California ; first coll. by Nuttall. 



§ 3. Paniculatelj branched annuals, not spinescent : pappus white and soft. 



L. rostrata, Gray. Stem erect, 1 to 3 feet high, striate, leafy, corymbose-paniculate : leaves 

 narrowly linear, attenuate to both ends, entire, obscurely 3-nerved ; cauline 3 to 7 inches 

 long, barely 2 lines wide ; uppermost slender-subulate : heads numerous, on scaly-bracteolate 

 erect peduncles : involucre over half-inch high, 8-9-flowered, of as many very narrowly linear 

 bracts and a few short calyculate ones : rays small and narrow, probably purplish : akenes 

 slender-fusiform, 4 or 5 lines long, distinctly attenuate at summit but not truly rostrate, 5-8- 

 striate, longer than the soft rather dull-white pappus. — Proc. Am. Acad. ix. 217. L. juncea, 

 var. rostrata. Gray, Proc. Acad. Philad. 1863, 69. — Plains along the eastern base of the 

 Rocky Mountains, from the Saskatchewan (Cypress Hills, Mucoun) to Wyoming and Colo- 

 rado, where first coll. by Hall & Harbour. 



L. exigua, Gray, 1. c. A span or two high, effusely paniculate from the base, bearing 

 numerous small heads terminating short-filiform divergent branchlets or peduncles : branches 

 not striate: radical leaves spatulate or oblong (about inch long), from nearly entire to run- 

 cinate-pinnatifid ; cauline small and entire, soon reduced to minute bracts : involucre oblong, 

 2 lines high, 4-5-flowered, of as many narrowly oblong bracts and one or two very small 

 calyculate ones : akenes not 2 lines long, gradually tapering from the truncate summit to 

 base, broadly 4-5-costate, or rather narrowly 4-5-sulcate, somewhat longer than the bright 

 white pappus. — Prenanthes exigua, Gray, PI. Wright, ii. 105. — Stony hills, S. E. New 

 Mexico, Wright. S. W. Utah, Parry, Palmer. Mohave Desert, S. E. California, Parish. 



230. TR6XIM0N, Nutt. (Probably from Tpwyco, rpwiofxat, to chew, of 

 no obvious application to this, or to the factitious genus, partly Krigia, partly 

 Scorzonera, for which Geertner coined the name.) — N. American with one or 

 two S. American herbs, acaulescent or nearly so, with a cluster of sessile or sub- 

 sessile radical leaves, and simple scapes bearing a head of yellow or rarely purple 

 flowers, in summer. Occasionally in one species some chaffy bracts among the 



