162 PROCEEDINGS OF THE AMERICAN ACADEMY. 



8; ligules 2-toothed, 10 to 15 mm. long; disk-flowers somewhat exceed- 

 ing the involucre, about equalling the produced tips of the pales; limb of 

 the corollas exceeding the tube, the lobes coarsely tomentose : ray-achenes 

 obovoid, 3 mm. long, broadly winged ; wings confluent with the awns and 

 squamellae ; disk-achenes oblong-turbiuate, subtriquetrous, costate, with 

 very caducous awns. — Bot. Gaz. xiii. 188 (1888). — Central America. 

 Specimens examined, — Guatemala : Aha Verapaz, Coban, alt. 1400 m. 

 von Tuecrkheim, no. 853 of J. D. Smith's distrib. 



= = = Achenes of botli the ray- and disk-flowers winged, or occasionally wings 

 wanting in the ray-flowers. 



a. Achenes long, narrow, not strongly constricted ; wings very narrow. South 

 American species. 



1. Outer involucral bracts long, foliaceous : ligules wanting. 



35. Z. foliosa, Rusby in herb. Nearly herbaceous, leafy-stemmed : 

 leaves commonly 1 to 2 dm. long, about half as broad, ovate, acuminate 

 at the apex, subcordate or somewhat attenuate at the base, serrate, above 

 strigose, beneath scabrous-puberulent ; petioles margined, 1 to 4 cm. long: 

 peduncles 1 to 3 cm. long, slender, pubescent, usually terminal and soli- 

 tary or in cymes of 3 ; heads 1 to 2 cm. high, subtended by many long 

 spreading foliaceous bracts ; involucral bracts caudate-attenuate, ciliate or 

 somewhat hirsute : rays none ; disk-corollas exceeding the pales, the black 

 anthers exserted : achenes narrowly winged, constricted, with short distinct 

 squamellae ; the marginal achenes 3-angled, 3-awned ; those of the interior 

 of the head compressed, 2-awned. — South America. Specimens exam- 

 ined, — Bolivia: Guanai-Tapuani, Bang, no. 1340 (type). Dr. Rusby 

 (Mem. Torr. Bot. Club, vi. pt. 1, p. 63) mentions this plant (without 

 specific name or characterization) and expresses a doubt whether it should 

 be included in Zexmenia on account of the foliaceous bracts of the in- 

 volucre and the absence of rays. However, it is closely related in achenial 

 characters to Z. wedelioides, and in general habit to several other species 

 of the genus. 



2. Outer bracts not long and foliaceous : ligules present. 



36. Z. wedelioides, Klatt. Stem woody, velvety-villous: leaves 

 elliptical or ovate, 5 to 8 cm. long, about 4 cm. wide, remotely serrulate, 

 above scabrous, beneath villous, acute or acuminate at the apex, obtuse 

 or rounded at the base: peduncles subumbellately clustered, short, 1 to 2 

 cm. long; heads generally less than 1 cm. high; invokicre subglobose ; 

 bracts oblong, acute, scabrous: achenes at maturity black, those of the 

 ray-flowers 3-, of the disk-flowers, 2-awned ; awns fragile, unequal, about 



