JONES. — A REVISION OF THE GENUS ZEXMENIA. 147 



outer involucral bracts obtuse ; the inner acute : one awn of the ray- 

 achenes about as long as the body of the achene ; squaniellae very small. 

 — Gen. ii. 373 (1873). Lipochaeta scuberrlma, Benth. in Hook. Journ. 

 Bot. ii. 43 (1840). — South America. No specimens seen. Type 

 collected by Schomburgk in the Roraiina Mountains of Guiana, 1840. 

 A doubtful species. 



■i- -i- Involucral bracts in 3 to 5 series. 

 ** Awns of the disk-achenes as long as the body. 



4. Z. Seemannii, Gray. Shrub, usually much-branched : leaves linear- 

 oblong to oblong-lanceolate, 2 to 10 cm. long, 7 to 15 mm. wide, acute 

 to rounded at the apex, acute or acuminate at the base, subentire, shin- 

 ing, hispid-scabrous above, glabrate beneath ; petioles 3 to 10 mm. long: 

 peduncles commonly fascicled or cymose in umbelliform clusters iu the 

 upper axils, 3 to 13 mm. long; heads about 15 mm. high; involucre 

 cylindrical, 5 to 8 mm. broad ; the involucral bracts about 5-seriate, lax 

 at the apex and variously toothed, the outer series very short ; the inner 

 much longer: ligules 6 to 8, about 1 cm. long: margined angles of the 

 achenes very prominent and confluent with the awns; body of the disk- 

 achenes 4 mm. long, 1.5 mm. wide ; squamellae about 1 mm. long, more 

 or less united. — PI. Wright, i. 114 (1852) ; Hemsl. Biol. Cent.-Am. 

 Bot. ii. 174. — Northern Mexico. Specimens examined^ — Cerro de 

 Pinal, Seemann, no. 1476 (type, in herb. Gray). Sinaloa : Sierra de 

 Choix, Goldman, no. 249. Tepic : Palmer, no. 1857, coll. of 1892. 



5. Z. helianthoides, Gray. Shrub or lignescent herb, 6 to 9 dm. 

 high ; branches stout : leaves 2 to 10 cm. long, ovate, subcordate, serrate 

 or subentire, reticulate-veiny, above warty-strigillose, beneath velvety- 

 villous ; petioles less than 1 cm. in length : peduncles 1 to 3 cm. long, 

 very stout, fascicled or occasionally solitary at the ends of the branches; 

 heads about 2 cm. long; involucre 10 to 15 mm. broad, its bracts about 

 4-seriate, ovate, appressed, entire, rouuded at the apex, the outer series 

 considerably shorter than the inner: ligules 8 to 16, rather small; disk- 

 corollas long and slender, much exceeding the involucre : achenes 4 to 

 6 mm. long, with margined angles much developed and confluent whh the 

 awns, these at least in the disk-achenes longer than the body of the 

 achene. — PI. Wright, i. 113 (1852); Hemsl. Biol. Cent.-Am. Bot. ii. 

 172; Sch. Bip. in Seemann, Bot. Voy. Herald, 305. Z. ovata, Benth. 

 & Hook. f. Gen. ii. 373 (1873). Lasianthus helianthoides, Zucc. in 

 Herb. Acad. Monac. according to Gray, 1. c. Lasianthaea helianthoides, 

 DC. Prodr. v. 608 (1836). Tithonia ovata, Hook. Bot. Mag. t. 3901 



