Prenanthcs. COMPOSITE. 433 



§ 1. NXbalus, Endl., with more contracted inflorescence, dull-colored flowers, 

 more nerved akenes (only in tlie last species tapering at summit), and stifter 

 sordid pajipus. (North American & North Asiatic.) — NahaluSy Cass. Diet, xliii. 

 281 ; Hook. Fl. i. 293 ; Torr. & Gray, Y\. ii. 480. Harpahjce, Don, in Edinb. 

 Phil. Jour. vi. 305, not DC. Fl. late summer and autumn. 



* Heads 20-35-flo\vered, comparatively broad, corj-mbosely paniculate: leaves mostly wing- 

 petioled. 



P. crepidinea, Micux. Minutely pubescent or partly glabrous : stem stout, 5 to 9 feet high, 

 branching above, leafy up to the short branches of indoresceuce : leaves ample, ovate-deltoid, 

 or radical hastate and uppermost oblong, acutely or laciniately dentate : involucre half to 

 two-tiiirds inch long, oblong-campauulate, sparsely hirsute : flowei-s ochroleucous : akenes 

 finely 12-lo-costate, four or five of the ribs stronger: pappus sordid. — Fl. ii. 84. HaTpalijce 

 crepicHna, Don ex Steud. JSfabuliis crepidincus, DC. Prodr. vii. 241 ; Torr. & Gray, 1. e. 483. 

 — Rich soil, Peun. and western borders of New York to Illinois and Kentucky ; first coll. by 

 Michaux. 



* * Heads 8-15-flowered, narrow, crowded or sometimes scattered in an elongated racemiform or 

 thyrsoid-virgate inflorescence which terminates the simple (1 to 5 feet high) stem : eauline 

 leaves sessile; radical and lower tapering intp winged petioles, not cordate or deltoid; all simply 

 pinnately veined: root usually fusiform-thickened or tuberous, simple or palmately branched. 



-t— Thyrsus hirsute or pubescent: heads little or not at all drooping, on pedicels much shorter than 



the involucre, 12-14-flowered: akenes at maturity about 15-nerved, somewhat angled b}- four or 



five of tiie nerves being stronger: stems leafy up to the strict thyrsus: leaves ordinarily onlj' 



denticulate, lower spatulate-oblong to obovate. 



P. aspera, Micux. I.e. Minutely scabrous-pubescent or below puberulent : upper leaves 



lanceolate, not clasping: thyrsus a foot or two long: involucre roughish-hirsute : flowers 



yellowish cream-color. — P. Illinoensis, Pers. Syn. ii. 36G ; Pursh, PI. ii. 500. Chondrilla 



Jlliiwmsis, Poir. Snppl. ii. 331. Ahihulus Illinoensis, DC. Prodr. vii. 242. N. asper, Torr. & 



Gray, 1. c. — Prairies and barrens, Ohio and Kentucky to Iowa and Louisiana; first coll. by 



Micfiaux. 



P. racemosa, Jlicax. 1. c. Leaves and stem glabrous and glaucous: upper eauline leaves 



lanceolate to ovate, partly clas])ing, the broader ones by cordate or auriculate base : thyrsus 



a span to 2 feet long': involucre i-ather loosely hirsute : flowers purplish. — Harjia!i/ce rucc- 



laoso, Don ex Steud. ; Beck, Bot. 168. Nahilus racemosus, DC. 1. c. ; Torr. & Gray, 1. c. — 



Moist or low ground, N. Maine and Canada, also Kew Jersey, to Saskatchewan and the 



Eocky Mountains, south to Colorado ; first coll. by Michaux. 



Var. pinnatifida. Large: leaves all lyrately or laciniately pinuatifid. — N, race- 

 mosus, var., Torr. & Gray, 1. c. — Ilacken-sack Marshes, Kew Jersey, Carcij. 



^ ^_ Th vrsus and whole plant smooth and glabrous : heads pendulous and more pedicellate, in a 

 looser racemiform thyrsus, 8-12-flowered : akenes about 5-nerved or angled, the intermediate 

 nerves obscure. 



P. Mainensis. About two feet high, leafy up to and into the panicle : leaves nearly those 

 of P. racemosa, but thinner and less glaucous ; the radical ovate, commonly with abrupt or 

 rounded base ; upper subtending clusters of the interrupted narrow thyrsus : heads all droop- 

 ing both before and after anthesis, resembling those of the following species. — Shore of the 

 St. John's River, at St. Francis, N. Maine, Primjie. Growing with or near P. racemosa. 

 And a looser form of the latter, "very common on the St. John's River," Goodale, is some- 

 what between the two ; so that this may be a hybrid of P. raceynosa with P. serpentaria. 



P. virgata, Miciix. 1. c. Glaucescent, very smooth, 2 to 4 feet high, very strict : radical 

 and lower leaves oblong-lanceolate, deeply sinuate-pinnatifid or pinnately parted, and divis- 

 ions sometimes lobed or few-toothed ; upper not clasping, decreasing to linear-lanceolate 

 and entire, and to small subulate bracts of the naked and slender (1 or 2 feet long) race- 

 miform inflorescence: flowers whitish or ])ale flesh-color: pappus sordid-stramineous. — 

 Willd. Spec. iii. 1533 ; Pursh, 1. c. ; Ell. Sk. ii. 258. P. outiimnalis, &c., Gronov. Fl. Yirg. ; 

 Walt. Car. 193. P. simplex, Pursh, 1. c. Harpali/ce virtjatn, Don ex Steud.; Beck, 1. c. 

 Nabalus virrjatiis, DC. 1. c. ; Torr. & Gray, 1. c. — Moist ground in pine barrens, Kew Jersey 

 to Florida, in the low country. 



28 



