422 COMPOSITE. Malacothrix. 



§ 2. Malacothrix proper. Involucre of narrow and acute or acuminate 

 bracts, only narrowly scarious-margined, much less imbricated: bristles on the 

 receptacle sparing, or fragile and deciduous, rarely none. — Leptoseris, Leucoseris, 

 & Malacomeris, Nutt. 



# Annuals: flowers light yellow, sometimes purplish in fading. 



+- Simply seapose, with solitary large head, about 3-serially imbricated involucre, and herbage 

 long-woolly when young. — Malacothrix, DC. 



M. Californica, DC. Leaves once or partly twice laciniately pinnatifid into narrow linear 

 or almost filiform lobes, when young woolly with long and loose very soft hairs (whence the 

 generic name), as also is the base of the broadly campanulate (two-thirds inch high) invo- 

 lucre ; the outer bracts slender-subulate : delicate bristles of the receptacle generally present : 

 akenes narrow, lightly striate-costate, the acutish base with a small concave callus : outer 

 pappus of 2 persistent bristles and between them some minute pointed teeth : scape a foot or* 

 less high, bractless or nearly so. — Prodr. vii. 192 ; Gray t 1. c, excl. var. glabrata, Eaton. — 

 Open grounds, California, from the Sacramento valley to San Diego ; first coll. by Douglas. 



•1— +- Subcaulescent or more leafy-stemmed, more or less branching, early glabrate or glabrous: 

 involucval bracts nearly or wholly of two lengths; the outer (or calyculus) short, proportionally 

 broader and loose. — Leptoseris, Nutt. 

 ++ Heads comparatively large, and on elongated or the earlier on scapiform peduncles : leaves and 

 their divisions long and slender, nearly as in the preceding species. 

 M. glabrata. Erect, or with ascending branches from the base, these leafy, often again 

 branching and bearing a few lateral as well as terminal heads : involucre fully half-inch 

 high, glabrous, or outer bracts sometimes tomentulose-canescent when young : flowers, &c, 

 as in M. Californica. — M. Californica, var. glabrata, Eaton, Bot. King Exp. 201 ; Gray, 

 Bot. Calif. 1. c. M. Torreyi, Gray, Proc. Am. Acad. ix. 213, as to "slender narrow-leaved 

 form." — Dry eastern portion of the Sierra Nevada in California and Nevada, to S. E. Utah 

 and Arizona ; first coll. by Anderson. 



++ ++ Heads smaller, with broadish campanulate involucre seldom less than half-inch high, 

 short-peduncled on the leafy usually spreading branches: lower leaves oblong, rather short, 

 pinnatifid, with short and dentate lobes; teeth and lobes commonly callous-mucfonate: plants 

 a span to a foot high. 



M. Torreyi, Gray. Akenes linear-oblong, 5-angled by as many salient often almost wing- 

 like ribs, a much less prominent pair in each interval: outer pappus of 2 to 5 or sometimes 

 8 stouter persistent bristles, between the thickish bases of which are minute teeth : bracts of 

 the involucre acuminate : peduncles commonly with some sparse gland-tipped hairs. — Proc. 

 Am. Acad. ix. 213, & Bot. Calif, i. 433. M. sonchoides, Torr. in Stansb. Kep. 392; Gray, 

 PI. Wright, ii. 105, in part; Eaton, Bot. King Exp. 201, not Torr. & Gray. — Low grounds, 

 Utah to W. Nevada and S. E. Oregon, probably to California; first coll. by Stansbury. 



M. sonohoid.es, Tore. & Gray. Akenes linear-obloDg, 1 5-striate-costate, somewhat angled 

 by 5 moderately stronger ribs, the summit with a 15-denticulate white border: no persistent 

 bristles : involucral bracts rather broader, merely acute : branches more diffuse : rhachis of 

 the principal leaves as well as lobes dentate. — El. ii. 486; Gray, 1. c. M. obtusa, Eaton, 

 1. c, in part. Leptoseris sonchoides, Nutt. Trans. Am. Phil. Soc. vii. 428. — Plains of W. Ne- 

 braska to New Mexico, Nevada, and adjacent California and Arizona ; first coll. by Nuttall. 



M. Pendleri, Gray. Akenes cylindrical, equably 1 5-costate, dark-colored ; the summit bor- 

 dered by a shallow cupulate crown, its margin entire, white within : no persistent pappus- 

 bristles or only one. — PI. Wright, ii. 104, Bot. Mex. Bound. 106, & Proc. Am. Acad. ix. 

 213. — E. New Mexico to S. E. California, Fendler, Bigelow, Wright, Lemmon, &c. 



++++++ Heads small, numerous and loosely paniculate on slender erect and rather naked stem 

 and branches: involucre seldom over 3 lines high, narrower, fewer-flowered: the tips of the 

 bracts commonly sphacelate or purplish. 



M. XAnti, Gray, 1. c, the only outlying species of the genus (Cape San Lucas, Lower Cali- 

 fornia, Xantus), is 2 feet high, with leaves mainly radical and lyrate-pinnatifid, panicle very 

 naked, narrow involucre 4 lines high, akenes obtusely 15-ribbed, five ribs moderately stronger, 

 cupulate apex obtusely 5-toothed, outer pappus of 3 to 5 very slender persistent bristles. 

 Heads larger than in either of the following. 



