Avfeinwrin. COMPOSIT^E. 339 



§ I. Bristles of (lie pappns of the sterile flowers hardly at all thickened hut sparsely 

 barbellate at the summit ; of the fertile flowers smooth : akene oblonrj linear, 

 cinereous with a minute 2nibescence, consisting of short bi-uncinate hairs ! 



1. A. dimorpha, Torr. & Gray. Depressed, fonuing close matted tufts only an 

 inch or two liigli : the thickish rootstocks creeping : leaves spatulate, silky-woolly 

 both sides, crowded on the branches of the rootst(.ick : heads solitary and sessile, 

 proportionally large, terminating extremely short or occasionally more developed (one 

 or two inches long) leafy steins : scales of the tur])inatc involucre mostly glabrous, 

 brownish ; those of the sterile head ovate-lanceolate, of the fertile more narrowly 

 lanceolate and acuminate. 



On tlie Sierra Nevada, along tlie eastern border of tlic State ; tlicnce nortliward and eastward 

 to and rather beyond the Rocky Mountains. There are two forms, one (var. Nuttallii, Eaton, in 

 Bot. King Exp.) with head only 3 or 4 lines long; the other (var. mncrocephiila, Eaton) with large 

 liead, the fertile when in fruit sometimes as much as 9 lines in length. On the Spi[>en River, 

 Washington Terr., a var. {flagcllaris) was gathered in the Wilkes Expedition, with liliform pro- 

 liferous shoots or stolons. 



§ 2. Bristles of the pappus of the sterile flowers clavate or thickened at the apex : 

 akene shorter, glabrous or minutely papillose : heads in a cluster {or occasion- 

 ally solitary) terminating a leafy or rarely scapiform jlowering stem. 



* Cespitose by means of surculose or stolon-like leafy sterile shoots from tlie base : up- 



rigid flowering stem simple. 



2. A. dioica, Gaertn. Eadical shoots forming broad matted tufts on the ground, 

 bearing rosettes of spatulate or oblanceolate white silvery-tomentose leaves : flower- 

 ing stems 2 to 10 inches liigh, bearing mostly linear heaves and several or numerous 

 beads in a close corymb : scales of the involucre with obtuse or roundish mostly 

 pearly- white but often rose-colored tips, of rather papery texture : bristles of the 

 pappus of the sterile flowers abrujitly dilated into a broad and flat tip. 



Sierra Nevada above Yoseniitc Valley, and northwanl. Throughout the Rocky Mountains and 

 tiiose of Nevada, Oregon, &c., usually at liigher elevations tlian in tlic Old World : collected in 

 the Klamath country by Dr. Cronkhitc, and Sierra Valley by Lcrmmm, with bright rose-colored 

 heads : doubtless the white forms not wanting in the northern and northeastern parts of the 

 State. Dr. Kellogg, in Proc. (_'alif. Acad. v. 45, has described this a-s a flnnpluiJium near O. 

 purpurcum, viz. G. Ncvadensc, Kellogg. 



3. A. alpina, Grertn. Radical shoots less tufted : leaves nearly as in the pro- 

 ceding, but less silvery : flowering stems an inch to 4 inches high, bearing a close 

 cluster of few heads, or sometimes n single head : scales of the involucre livid-brown 

 and thin-scarious (occasionally the innermost with white or whitish tips), acute or 

 acutish in the fertile, more obtuse in the sterile heads : bristles of the pappus in 

 the latter with less abrupt and broad tips. 



Along the Sierra Nevada at 10,000 feet or more, and in the alpine portion of the Rocky Moun- 

 tains, extending to the arctic regions, also in the Old World. 



* * Destitute of stolons or prostrate sterile shoots, or with few very short ascending ones. 



+■ Stems simple and virgate from a rather stout rootstock, the naked summit bearing a 

 corymb of broad heads : bristles of sterile pappus with conspicuously dilated tips. 



4. A. Carpathica, I\. Brown. Silvery white-woolly : stems a span to a foot 

 or more high : radical and lower leaves lanceolate and ohlanceolate, conspicuously 

 3-nerved ; the upper becoming linear : beads large (at least the fertile ones 4 or /) 

 lines long), few or several in a close corymbose cluster : involucre very woolly 

 and turbinate at base ; its scales livid or brownish and in the sterile heads with ob- 

 tuse white tips, those of the fertile beads more scarious and acutish or acute : akencs 

 smooth and glabrou.g. — The form corresi)onding with the European plant about a 

 span high. 



