APRIL, 1904. PLANTS YUCATAN^: MILLSPAUGH & CHASE. 127 



hispida Gray; and in its involucral characters it is quite similar to the 

 West African species Eleutheranthera dorsuosa Klatt. From the latter 

 genus, hmvever, our plant differs materially by the presence of distinct 

 apical appendages to the anthers; and in the oblique neck of the achene. 



Hab. "Herb, 18 inches, abundant in open places near Izamal, 

 Jan. to Dec." Gaunter 400 (Tridax procumbens canescens Field Col. 

 Mus. Bot. 1:325), "herb, 4 feet high, flowers white, common in old 

 fields, Aug. to Sept." Izamal, 792, common in open forests Buena 

 Vista Xbac, April, 1053 (type), San Anselmo 



ZEXMENIA Llav. et Lex. Nov. Veg. Desc., 1:13. 



Heads heterogamous, radiate; ray flowers pistillate, fertile, Hgu- 

 late; disk flowers perfect, fertile, tubular. Involucre wide campanu- 

 late of subequal bracts, imbricated in 2 or 3 series, outer herbaceous, 

 inner dry. Receptacle plane or convex, chaffy; scales complicate, 

 embracing the disk flowers. Achenes in Sec. Wedelioides: hetero- 

 morphus, winged or wingless, constricted into a neck, pappus of 

 laciniate scales connate into a crown, the bristles not apparent; in 

 Sec. Lipochceta: dimorphous, wingless, 3 angled and 3 awned or com- 

 pressed 4 angled and 2 awned, apex truncate; pappus of slender scab- 

 rous awns and minute intermediate scales, connate. Perennial herbs 

 or slender shrubs with rather showy heads of yellow flowers. 



Zexmenia hispida ramosissima Greenman Proc. Am. Acad. 



An erect, perennial herb with repeatedly forking, terete, slender, 

 hispid branches and opposite, rhombic-lanceolate, acuminate leaves 

 tapering into a hispid-ciliate petiole, irregularly dentate, tuberculate- 

 hispid above, paler, less harshly pubescent beneath. Inflorescence of 

 solitary or 2 or 3 loosely clustered heads, terminating the numerous 

 branches or in the upper axils; peduncles slender, subflexuous, hispid 

 with spreading hairs. Heads 8 mm. high, 2-2.5 cm - broad, ray flow- 

 ers 8-10, disk flowers numerous. Involucre campanulate, bracts in 2 

 series of 5 each, appressed, with loose or spreading tips, the outer 

 longer, herbaceous, lanceolate, acuminate, tuberculate-hispid, espe- 



cially at the base ; inner membrana- 

 ceous oblong, abruptly acuminate, 

 hispid at the summit. Corollas 

 orange yellow, ray with short tube, 

 ligule elliptical, 8-10 mm. long, 

 minutely bidentate, spreading; disk 

 corollas cylindrical, 5 lobed, pubes- 

 j- cent. Receptacle slightly convex; 

 ' scales oblong, obtuse, pubescent- 

 fimbriate at the summit. Achenes 

 heteromorphous, those of ray flow- 

 ers black with stramineous or dark 



wings (including wings and pappus 3.7x5 mm. obcordate), achene 

 proper 1.8 x 4. 5 mm. ; in section depressed 3 sided, the dorsum convex, 

 ventral angle rounded; narrowly obovate, constricted into a short 

 neck, dorsally compressed, the lateral angles bearing wings i mm. 



