Heads many-flowered, radiate; rays several, wedge-shaped, 3--5-cleft, fertile or rarely sterile. Involucre small, reflexed, the scales linear or awl-shaped. Receptacle globose or oblong, naked. Achenes top-shaped, ribbed; pappus of 5--8 thin and 1-nerved chaffy scales, the nerve usually extended into a bristle or point.--Erect, branching herbs (ours perennial), with alternate leaves decurrent on the angled stem and branches, which are terminated by single or corymbed (yellow, rarely purple) heads; often sprinkled with bitter aromatic resinous globules. (The Greek name of some plant, said to be named after _Helenus_, son of Priam.) 1. H. nudiflòrum, Nutt. Somewhat puberulent, 1--3° high; leaves narrowly lanceolate or oblong to linear, entire, or the radical spatulate and dentate; heads mostly small; disk brownish, globose; ray yellow or partly brown-purple, sterile (neutral or style abortive), shorter than or exceeding the disk. (Leptopoda brachypoda, _Torr. & Gray_.)--Ill. and Mo. to N. Car. and Tex.; nat. near Philadelphia. Hybridizes with the next. June--Aug. 2. H. autumnàle, L. Nearly smooth, 1--6° high; leaves mostly toothed, lanceolate to ovate-oblong; heads larger (about 6´´ broad); disk yellow; ray fertile, yellow.--Alluvial river-banks and wet ground, Conn. to Minn., south and westward. Sept. 64. GAILLÁRDIA, Foug. Heads many-flowered; rays 3-cleft or -toothed, neutral or sometimes fertile, or none. Involucral scales in 2--3 rows, the outer larger, loose and foliaceous. Receptacle convex to globose, beset with bristle-like or subulate or short and soft chaff. Achenes top-shaped, 5-costate, villous; pappus of 5--10 long thin scales, awn-tipped by the excurrent nerve.--Erect herbs with alternate leaves and large showy heads of yellow or purplish fragrant flowers on terminal or scapiform peduncles. (Named after _Gaillard de Merentonneau_.) 1. G. símplex, Scheele. Annual; leaves all radical, usually spatulate, pinnatifid to entire; head globose on a naked scape, usually rayless.--S. Kan. to Tex. 2. G. lanceolàta, Michx. Annual, leafy-stemmed, branched, 1--2° high, finely pubescent; leaves oblanceolate to linear, mostly entire; rays rather few or none; chaff very short or obsolete.--S. Kan. to Tex. and Fla. 3. G. aristàta, Pursh. Perennial, hirsute, often 2° high; leaves lanceolate to oblanceolate, broad or narrow, entire to coarsely pinnatifid; rays usually numerous and long; chaff bristly or subulate.--Dak., west and southward. 65. DYSÒDIA, Cav. FETID MARIGOLD.