844 COMPOSITAE (COMPOSITE FAMILY) 



heads. (Name from TroXri-, many, and TTT^US (wrephv), wing, referring to the 

 pappus of some species.) 



1. P. callbsa (Nutt.) Gray. Annual, slender, 6 dm. or less in height; leaves 

 linear ; peduncles glandular ; involucral bracts with dry reddish tips. Dry soil, 

 Mo. to Tex. , etc. 



63. ACTfNEA Juss. 



Heads many-flowered ; rays several, wedge-oblong, 3-toothed, pistillate. 

 Bracts of the hemispherical involucre ovate or lanceolate, membranaceous or 

 coriaceous, nearly equal, in 2-3 ranks, little shorter than the disk. Achenes 

 top-shaped, densely silky-villous ; pappus of 5 or more ovate or lanceolate very 

 thin chaffy scales. Low herbs, with narrow alternate leaves, dotted with 

 resinous atoms and bitter-aromatic ; the solitary heads terminating scapes or 

 slender naked peduncles ; flowers yellow. (Name from d/trk, ray.} ACTINELLA 

 Pers. PICRADENIA Hook. TETRANEURIS Greene. 



1. A. herbacea (Greene) Robinson. Perennial, caespitose ; branches of the 

 caudex rather stout, bearing numerous thickish spatulate to linear 1-nerved 

 sparingly villous glandular-punctate leaves and scape-like peduncles (villous or 

 Ian ate especially toward the summit) ; heads (including the showy rays) 3-4 

 cm. in diameter. ( Tetraneuris Greene ; Actinella acaulis, var. glabra Gray, in 

 part.) Ottawa Co., O., and about Joliet, 111. 



64. HELENIUM L, SNEEZE WEED 



Heads many-flowered, radiate ; rays several, wedge-shaped, 3-5-cleft, fertile, 

 rarely sterile. Involucre small, reflexed ; the bracts linear or awl-shaped. 

 Receptacle globose or ellipsoid. Achenes top-shaped, ribbed ; pappus of 5-8 

 thin 1-nerved chaffy scales, the nerve usually extended into a bristle or point. 

 Erect branching herbs with alternate leaves, often sprinkled with bitter 

 aromatic resinous globules ; heads yellow, rarely purple, terminal, single or 

 corymbed. (The Greek name of some plant, said to be named after Helenus, 

 son of Priam.) 



* Leaves broad, decurrent on the angled stem. 



1. H. nudiflbrum Nutt. Perennial, somewhat puberulent, 3-9 dm. high ; 

 leaves narrowly lanceolate or oblong to linear, entire, or the radical spatulate 

 and dentate ; heads mostly small ; disk brownish, globose ; rays yellow or 

 partly brown-purple, sterile (neutral or style abortive), shorter than or exceed- 

 ing the disk. 111. and Mo. to N. C. and Tex. ; also abundantly established 

 locally from N. E. to Pa. June-Aug. Hybridizes with the next. 



2. H. autumnale L. Perennial, nearly smooth, 0.2-2 m. high ; leaves mostly 

 toothed, lanceolate to ovate-oblong; heads larger (2-4 cm. broad) ; disk yellow ; 

 rays fertile, yellow. Alluvial river-banks and wet ground, w. Que. and w. 

 Mass, to Man. , southw. and westw. Aug.-Oct. 



* * Leaves linear-filiform, not decurrent. 



3. H. tenuifblium Nutt. Glabrous annual, much branched, very leafy ; heads 

 1.5-2 cm. broad; rays fertile. Prairies, roadsides, etc., Va. to Kan., and 

 southw. ; locally established by railroads, etc., northeastw. to e. Mass. 



65. GAILLARDIA Foug. 



Heads many-flowered ; rays 3-cleft or -toothed, neutral or sometimes fertile, 

 or none. Involucral bracts in 2-3 rows, the outer larger, loose, and foliaceous. 

 Receptacle convex to globose, with bristle-like or subulate or short and soft 

 chaff. Achenes top-shaped, 6-costate, villous ; pappus of 5-10 long thin awn- 

 tipped scales. Erect alternate-leaved herbs with long-peduncled showy heads 

 of yellow or purplish fragrant flowers. (Named after Gaillard de Charenton- 

 neau, a botanical amateur.) 



