Aplopappus. COMPOSITE. 125 



t. 10. Centauridium Drummondii, Torr. & Gray, PI. ii. 246 ; Gray, PI. Lindh. ii. 223. 

 Machceranthera grandi/lora, Buckley in Proc. Acad. Philad. 1861, 456. — Open woods, Texas 

 Berlandier, Drummond, Lindheimer, &c. ; fl. all summer. 



30. APLOPAPPUS, Cass. ('AirAoos, 7rdWos, simple pappus.) — A large 

 American genus (chiefly W. North American and Chilian) the analogue of Aster 

 in the heterochromous division and equally polymorphous ; mostly herbaceous 

 perennials, some suffruticose or even shrubby, a few annual: the flowers all 

 yellow, produced in summer and autumn. — Diet. lvi. 1 68. Haplopappus & Eri- 

 cameria, Benth. & Hook. Gen. ii. 253, 255. — Note that one or two species 

 occasionally and certain species uniformly want the ray-flowers, obliterating the 

 distinction between this genus and the following ! 



§ 1. Prionopsis, Gray. Heads very large and broad: involucre depressed- 

 hemispherical, of lanceolate acuminate bracts, the outer mostly foliaceous and 

 spreading : rays very numerous : disk-corollas narrow, merely 5-toothed : style- 

 appendages short and rather obtuse: akenes very glabrous; those of the ray 

 short, turgid-elliptical ; of the disk oblong or narrower, and the central ones 

 inane: pappus of very rigid and unequal bristles and comparatively little nu- 

 merous ; the innermost and larger ones somewhat flattened toward the base and 

 their margins scabrous-ciliolate ; the outermost very small and short : root annual 

 or biennial. — PI. Wright, i. 98. Prionopsis, Nutt. Trans. Am. Phil. Soc. 

 n. ser. vii. 329. — (Connects with Xanthisma and has the foliage of G-rindelia.) 



A. Ciliatus, DC. Very glabrous : stem 2 to 5 feet high, bearing few or several somewhat 

 cymose-clustered heads (with the disk an inch in diameter), equably leafy to the top : leaves 

 oval or the lower obovate (1 to 3 inches long), very obtuse, veiny, evenly and somewhat 

 pectinately dentate with bristle-pointed teeth : pappus of the fertile akenes disposed to be 

 deciduous in a ring. — Prodr. v. 346; Gray, PI. Wright, i. 98. Donia ciliata, Nutt. Jour. 

 Acad. Philad. ii. 118; Hook. Exot. Fl. i. t. 45. Prionopsis ciliata, Nutt. 1. c. ; Torr. & 

 Gray, PI. ii. 245. — Hillsides and river-banks, Missouri and Kansas to Texas. 



§ 2. Aplopapptjs proper. Heads large or middle-sized, or sometimes small, 

 commonly broad and with involucre of firm well-imbricated or rigid bracts : rays 

 numerous, several, or rarely wanting : disk-corollas narrow, merely 5-toothed : 

 style-appendages from ovate to linear-subulate: pappus commonly fuscous or 

 rufous, and more or less rigid. (Habit and special characters various, but the 

 groups too confluent and indefinite for first-class sections.) 



# Heads rayless : bracts of the involucre rigid, appressed-imbricate with the outer successively 

 shorter, all with abrupt and more or less spreading herbaceous tips: style-appendages ovate- or 

 oblong-lanceolate: pappus rather rigid: leaves coriaceous, mostly oblong and spinulose-dentate. 

 — Aplopappvs § Aplodiscus, Torr. & Gray, Fl. ii. 242, excl. the first species, which is § Aplodis- 

 cus, DC. § Hapludiscus & Eriocarpcea, Benth. & Hook. 1. u. — (One of the transitions to Bige- 

 lovia § Aplodiscus.) 



A. squaiTOSUS, Hook. & Arn. Suffruticose, 2 or 3 feet high, somewhat pubescent, gland- 

 ular and glutinous : leaves thickly dentate (about inch long) : heads numerous and spicately 

 thyrsoid at the end of the branches, half-inch long : involucre elongated-turbinate ; its bracts 

 imbricated in many ranks, the lower usually imbricated on the peduncle, their tips mostly 

 squarrose and glandular: akenes fusiform, glabrous, or sparsely pubescent. — Bot. Beech. 

 146; Torr. & Gray, PI. ii. 242. Pyrrocoma grindelioides, DC. Prodr. v. 350. Homopappus 

 squarrosus, Nutt. Trans. Am. Phil. Soc. 1. c. 332. — Dry hills on the coast of California, from 

 Monterey to San Diego ; first coll. by Douglas. Also on the foot-hills of the San Bernardino 

 Mountains, Parish, &c. 



A. Nuttallii, Torr. & Gray, 1. c. Herbaceous from a ligneous stock, a span to a foot 

 high : leaves from spatulateoblong to almost lanceolate, rather Sparsely pectinately dentate : 



