Aplopappus. COMPOSITiE. 125 



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

 Machceranthera grandijiorn, Buckley in Proc. Acad. Philad. 1861, 456. — Open woods, Texas, 

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



30. APLOPAPPUS, Cass. ('AttAo'os, TrarrTro?, simple papiius.) — A large 

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

 in the heterochromovis 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. Ivi. 1G8. Haplopappus & Eri- 

 cameria, Benth. & Hook. Gen. ii. 253, 25.5. — 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 : stjde- 

 api^endages 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 comjiaratively 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 Grindelia.) 



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 

 pectiuately 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 cilinta, Nutt. Jour. 

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

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



§ 2. Aplopappus 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 conunonly 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: lenves coriaceous, mostly oblong and spinulose-dentate. 

 — Aplopappus § Aplixlisriis, Torr. & Gray, Fl. ii. 242, excl. the lirst species, which is § Aplndis- 

 CVS, DC. § ITapludiscus & Eriocarpcea, Benth. & Hook. 1. c. — (One of the transitions to Bt(/c- 

 loria § Aplodiscus.) 



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

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

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

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

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

 146; Torr. & Gray, Fl. ii. 242. Pt/rrocoma (jrindelioides, DC. Prodr. v. 350. Homopappus 

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

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

 Mountains, Parish, &c. 



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

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



