JONES. — A REVISION OP THE GENUS ZEXMENIA. 1G1 



■+-*••*-*• Awns long, bristle-like ; body of the achene usually exceeding 3 mm. in length. 

 = Achenes wingless. 

 a. Squamellae distinct. 



32. Z. auraxtiaca, Klatt. Stem woody, branching, scabrous: leaves 

 ovate, serrulate, acuminate at both ends, above scabrous or strigose, be- 

 neath somewhat pilose; petioles margined, clasping, about 2 cm. long: 

 peduncles 4 to 12 cm. long, terminal, commonly solitary or in a cyme of 

 3; heads 10 to 15 mm. high; involucre cylindrical, about 1 cm. broad, 

 2-seriate ; outer bracts herbaceous, generally reflexed at the apex, ovate- 

 lanceolate, densely pubescent : ray-flowers about 15 ; ligules broadly ovate, 

 tridentate : pales trifid, purple or violet at the apex : achenes 4 to 5 mm. 

 long, slender, very slightly constricted, with very fragile plumose awns, 

 generally only one as long as the body, and several unequal bristle-like 

 squamellae; achenes of the ray-flowers 4-, of the disk-flowers, 3-angled. 

 — Bull. Soc. Bot. Belg. xxxv. 296 (1896). — Central America. Speci- 

 mens examined, — Costa Rica: thickets on the banks of Virilla River, 

 Tonduz, no. 9836 (type, in herb. Gray). This species may not belong 

 to Zexmenia. The shape of the achene is exceptional and the pappus 

 somewhat resembles that of a Perymenium. 



b. Squamellae united ; awns rather rigid, subequal. 



33. Z. strigosa, Sch. Bip. Suffruticose : leaves short-petioled, ovate- 

 lanceolate, very acute, serrulate, above sparsely strigose, beneath ap- 

 pressed villous : peduncles terminal, monocephalous ; involucre 2-seriate ; 

 bracts lanceolate, the outer foliaceous, strigose : achenes 5 to 7 mm. long, 

 slender, very slightly constricted above, wingless, 2-3-awned ; squamellae 

 united between the awns but free from them, about 1 mm. long. — 

 Sch. Bip. in Seemann, Bot. Voy. Herald, 306 (1852-57). Lipochaeta 

 strigosa, DC. Prodr. v. 610 (1836). — Southern Mexico. Specimens 

 examined, — Oaxaca : Andrieux, no. 313, fragments lent from the De 

 Candollean Herbarium. 



= = Achenes of the ray-flowers winged ; those of the disk-flowers wingless. 



34. Z. guatemalensis, J. D. Smith. Fruticose, somewhat scabrous, 

 covered with a whitish pilosity : leaves ovate-lanceolate, muriculate- 

 scabrous above, pilose beneath, mucronulately serrulate, acute or acumi- 

 nate at the apex, obtuse or rounded at the base ; petioles margined, less 

 than 1 cm. long: peduncles canescent-hirsute, slender, 0.5 to several cm. 

 long, subumbellate ; heads about 1 cm. high ; involucre 2-seriate, cam- 

 panulate ; outer bracts slightly the longest, densely pubescent : ray-flowers 



VOL. xli. — 11 



