I2O 



FIELD COLUMBIAN MUSEUM BOTANY, VOL. III. 



acuminate, 3 nerved, entire leaves, hispid above, appressed pilose 

 or silky canescent beneath. Inflorescence an open, leafy, corymbose 

 panicle of several to many heads; branches sometimes sparingly 

 pubescent, peduncles pubescent at least toward the summit. Heads 

 7-8 mm. high, 2-2.5 cm - broad, ray flowers 8-10, disk flowers numer- 

 ous. Involucral bracts in 2-3 series, subequal, lanceolate, abruptly 

 narrowed into a linear, spreading tip, hirsute, especially on the mar- 

 gins and tips. Corollas yellow, ray with a short tube, ligule elliptic, 

 6-8 mm. long, minutely bidentate, spreading; disk corollas densely 

 hirsute, 5 lobed. Receptacle convex, becoming obtuse conoid; scales 

 oblong-ovate, with rigid, acute tips, nearly as long as the disk flowers. 

 Achene black, 1.4x3 mm. cuneate; in section biconvex, the angles 

 acute; densely covered with tawny, stiff, appressed hairs; pappus 



awns 2.2-3 mm., denticulate, the 

 intermediate scales 1.2 mm., usu- 

 ally connate, laciniate, tawny, 

 marked with dark purple. 



Hab. Suburbs of Merida, Jan. 

 14, 1865, Schott 190; Cozumel 1886, 

 Gaumer (Oliver); abundant near 

 Merida, Valdez // ; "herb 2 to 5 

 feet high, very abundant in old 

 fields about Izamal and Xcholac, 

 Oct. to May," Gaumer 502, 557, 

 Chichankanab 1814, Calotmul 1815; 

 Ticui, Feb. 18, 1903; Cw.c. et. Ed. 

 Seler 3863, Chichen Itza, Mch. 

 2I > i93, 4003. 



Yucatan specimens vary from 

 the typical form in having smaller 

 heads, narrower tipped involucral 



bracts; achenes more densely pilose and intermediate scales of the 

 pappus nearly always completely connate. The under surface of the 

 leaves is more softly canescent than usual in other specimens. 



Called TAH, "Torch brush," by the Mayas and used by them as a 

 pectoral in chronic coughs. 



HELIANTHUS L. Sp. PL, 904.' 



Heads heterogamous, radiate, ray flowers neutral, ligulate; disk 

 flowers perfect, fertile, tubular. Involucre depressed, of*herbaceous 

 bracts imbricated in several series. Receptacle plane or convex, 

 chaffy; scales subtending' the perfect flowers. Achenes laterally com- 

 pressed; pappus of 2 deciduous scales or awns. Annual or perennial 

 herbs with large showy heads of yellow rays and (in our species) 

 purple disk. 



Helianthus animus L. Sp. PL, 904. 



A robust annual, branched above, with stout, hispid stem and 

 alternate (except the lowest), petioled, ovate, acute, dentate, 3 nerved 

 leaves; rough-hispid on both sides. Inflorescence of solitary heads 



