Prionopsis. composite. 246 



49. PRIONOPSIS. Nidt. in trans. Amer. phil. soc. («. ser.) 7. p. 329. 



Heads broadly hemispherical, many-flowered ; the rays numerous (in a 

 single series), ligulate, pistillate ; those of the disk tubular, perfect, but more 

 or less infertile. Scales of the involucre very numerous, lanceolate, cuspi- 

 date, somewhat unequal, the exterior squarrose and foliaceous. Receptacle 

 broad and flat, slightly alveolate. Corolla of the disk slightly dilated up- 

 wards, 5-toothed. Appendages of the style in the disk-flowers lanceolate- 

 oblong, obtuse, rather short. Achenia short, very glabrous, somewhat striate, 

 turgid; in the ray oval; in the disk cylindrical-oblong, or the infertile oblong- 

 linear. Pappus deciduous, composed of copious and very unequal rigid 

 scabrous bristles ; the inner series (5-10) setose and stronger than the others, 

 longer than the corolla (of the disk) and much longer than the achenia; the 

 others successively shorter and more slender. — Stout biennial plants, with 

 the aspect and spinulose-toothed leaves of Grindelia. Heads large and 

 showy : flowers yellow. 



The short and very smooth achenia, and the deciduous pappus, form the chief, if 

 not the only distinctions between this genus and true Aplopappus : we are not suffi- 

 ciently acquainted with the South American species to judge of the importance of 

 these characters. The perennial species from Florida here subjoined, has short and 

 glabrous ovaries, but perhaps a persistent pappus : if so, this ge'nus should probably 

 be considered a section of Aplopappus. 



1. P. ciliata (Nutt. ! I.e.): glabrous; stem stout, simple or sparingly 

 branched ; leaves elUptical, very obtuse, partly clasping, somewhat veiny, 

 closely and sharply serrate-toothed, the teeth all pointed with bristles. — Donia 

 ciliata, Nutt..' in jour. acad. Philad. 2. p. 118; HooJc. exoL. ji. 1. t. 45. 

 Aplopappus (Leiachenium) ciliatus, DC! j^rodr. 5. p. 346. 



Arkansas, on the alluvial banks of Great Salt River, Nuttall ! Texas, 

 Drummond! Aug.-Oct. — Stem about 3 feet high. Involucre an inch in 

 diameter, somewhat glutinous. Pappus of the ray rather shorter than in the 

 disk, often deciduous in a ring. Inner bristles of the pappus terete, attenu- 

 ate from the base to the middle, and tlience obscurely thickened upwards; 

 the outermost very slender and scarcely exceeding the achenia, the others 

 intermediate in size, &c. 



2. P.? Chapmanii : stems simple, virgate, hirsute-pubescent; leaves erect, 

 numerous, narrowly lanceolate or linear, glabrous, pungently acute, seta- 

 ceously serrate; the radical ones elongated; the uppermost short, some- 

 what hairy, appressed ; scales of the involucre lanceolate, very acute or cus- 

 pidate, S(iuarrose ; rays elongated. 



Swamps in pine barrens, Middle Florida, Br. Chapman! June-July — 

 U Stem 1-2 feet high, bearing 1 to 3 or 4 heads. Leaves slightly nerved ; 

 the radical ones clustered, 4-6 inches long, tapering to the base, sometimes 

 entire ; the cauline successively decreasing in length, serrate with scattered 

 bristly teeth, much as in Eryngium aquaticum. Head about three-fourths 

 of an inch in diameter ; the" involucre rather shorter than (he disk. Recep- 

 tacle broad and flat, slightly alveolate and fimbrillate. Rays 30-40, nar- 

 rowly linear. A[)pendages of the style in the disk-flowers narrowly lanceo- 

 late, longer than the stigmatic portion. Achenia (inunature) very short. 

 Pappus rigid, ferruginous, nearly as in the preceding, but the bristles less 

 unequal.— We have not seen the mature achenia, and are not entirely sure 

 that the rays are yellow. 



