STAISTDLEY TREES AND SHEUBS OF MEXICO 1563 



Herbaceous, at least above; stem almost glabrous; branches superaxillary; 

 leaves mueh as in no. 1; heads usually ternate, the peduncles 2.5 to 8 cm. long; 

 involucre 3-seriate, the phyllaries ovate, acute or acuminate, the herbaceous tips' 

 usually spreading; achenes glabrous, epappose. 



70. PODACHAENIUM Benth. in Oerst. Nat. For. Kjobenhavn Vid. Medd 



1852: 98. 1852. 



Reference: Blake, Contr. Gray Herb. n. ser. 52: 50. 1917. 

 1. Podachaenium eminens (Lag.) Schultz Bip. Flora 44: 557. 1861. 



Ferdinanda eyninens Lag. Gen. & Sp. Nov. 31. 1816. 



Podachaeniu7n paniculatum Benth. in Oerst. Nat. For. Kjobenhavn Vid. 

 Medd. 1852: 99. 1852. 



Dicalymma fragrans Lem. 111. Hort. 2: Misc. 37. /. 1-3. 1855. 



Cosmophyllum cacaliaefolium Koch & Bouche, Ind. Sem. Hort. Berol. 1854: 

 12. 1854; Walp. Ann. Bot. 5: 219. 1858. 



Sinaloa to Veracruz and Oaxaca; type from Mexico, without definite locality, 

 Guatemala to Costa Rica. 



Stout shrub, up to 8 meters high, sordid-tomentulose; leaves opposite, or the 

 upper alternate, petioled; blades ovate to suborbicular, up to 30 cm. long and 

 wide, entire or angulate-toothed or lobed, green above, griseous-tomentulose 

 beneath; heads very numerous in a terminal panicle, 1.5 to 2.5 cm. wide; rays 

 white, disk yellow; achenes compressed, about 2 mm. long, with whitish stipiti- 

 form base; pappus of 2 awns and several squamellae. "Tacote" (Sinaloa); 

 ^'tora" (Costa Rica.) 



In Sinaloa the fragrant leaves are applied as poultices to wounds. 



71. ACHAENIPODIUM T. S. Brandeg. Zoe 5: 239. 1906. 

 1. AchaenipodiuiTi discoideum T. S. Brandeg. Zoe 5: 239. 1906. 



Known only from the type locality, Mount Ixtaccihuatl, State of Mexico. 



Suffrutescent; stem hirsute; leaves opposite, short-petioled, the blades lanceo- 

 late, 10 to 14 cm. long, 2 to 3 cm. wide, acuminate, serrate, penninerved, griseous- 

 pilose beneath; heads panicled, yellow, discoid, about 7 mm. wide; achenes com- 

 pressed, long-stipitate, about 5 mm. long, 1 mm. wide; pappus of 2 setiform 

 awns. 



72. ZEXMENIA Llave in Llave & Lex. Nov. Veg. Descr. 1: 13. 1824. 

 Reference: W. W. Jones, A revision of the genus Zexmenia, Proc. Amer. 

 Acad. 41: 143-167. 1905. 



Shrubs or herbs; leaves opposite, rarely alternate, usuall}' ovate, serrate, and 

 petiolate; heads solitary, umbellate-cymose, or panicled, radiate, yellow (the 

 rays saffron in one species); involucre 2 to 5-seriate, graduate or subequal, the 

 phyllaries usually ovate or oblong and with herbaceous tips; rays fertile; recep- 

 tacle paleaceous; disk achenes more or less compressed, mostly oblong or obovate, 

 acute-margined or sometimes winged; pappus of 2 or 3 awns and' several usually 

 more or less connate squamellae, the latter sometimes reduced to an entire crown 

 or obsolete. 



Heads solitary or ternate at tip of steiii, long-peduncled; peduncles mostly 5 to 

 25 cm. long. 

 Leaves densely canescent-tomentose beneath. 



Leaves toothed 19. Z. pringlei. 



Leaves entire 20. Z. gnaphalioides. 



Leaves not tomentose beneath. 



Leaves smaller, not over 5 cm. long. 



Leaves chiefly alternate, entire 21. Z. brevifolia. 



