APRIL, 1904. PLANTS YUCATAN^ MILLSPAUGH & CHASE. 101 



peduncles striate, glabrous, covered with a resinous exudation. Pistil- 

 late heads 12-14 mm. high, 4-5 mm. broad. Involucral bracts imbri- 

 cated in 4 series, the outer ovate 

 to oblong, obtuse, tinged with 

 purplish olive, more or less resin- 

 ous; inner lanceolate, subacute, 

 fimbriate, paler, much exceeded 

 by the pappus. Corolla short, 

 white. Achene yellw, .5 x 1.5 

 mm., obliquely obconoid; in 

 section oval-oblong; strongly 10 

 ribbed, glabrous; pappus bristles 

 copious, soft, silky, white, or 

 pale pinkish tawny, smooth, 

 10-13 mm. long. Sterile heads 

 similar, involucre slightly smal- 

 ler, achenes abortive; pappus, 

 barbellate, plumose at the sum- 

 mit, 3-5 mm. long. 



Hab. "Shrub, 6 feet high, not common at Chichankanab" 

 Gaumer 1376, Pocoboch 2367. 



The species varies greatly in the shape of the leaves. Our speci- 

 mens are without lower leaves; those of the inflorescence are oblance- 

 olate, entire. 



PLUCHEA Cass. Bull. Philom., 1817:31. 



Heads heterogamous, discoid; outer flowers in many series, pistil- 

 late, fertile, corolla reduced to a slender tube; central flowers perfect, 

 sterile, the corolla tubular, 5 cleft. Involucre wide campanulate, of 

 membranaceous bracts imbricated in several series, the outer gradu- 

 ally shorter. Receptacle naked, plane. Achene laterally compressed, 

 nerved; pappus of i series of spreading slender bristles. Herbs with 

 dense cymes of flesh color or pale purple flowers. 



Achene strongly nerved, internerves resin dotted 

 Achene faintly nerved, internerves not resinous 



camphorata 

 odorata 



Pluchea camphorata (L.) DC. Prod., 5:452. 



Erigeron camphoratum L. 



An erect, branching, heavy-scented annual, with angled stems 

 and branches and alternate, petioled, oblong-lanceolate, acute, dentate 

 leaves, minutely glandular-puberulent. Inflorescence a broad or flat- 

 topped compound corymb of cymose clusters of several to many 

 heads; branchlets and pedicels densely glandular-puberulent. Heads 

 6-7 mm. high, 9-10 mm. broad, many flowered. Involucral bracts in 

 3 series, tinged with rose purple, acuminate, the outer ovate, glandu- 

 lar-puberulent, ciliolate; inner lanceolate to linear-lanceolate, with a 

 median line of glandular puberulence, ciliolate, the tips erect or 

 spreading, as long as the pappus. Corollas rose purple. Achene 

 purplish brown, .3x1 mm., oblong narrowed at the base, suboblique; 



