ROBINSON AND GREENMAN. — GENUS TRIDAX. 7 



Soc. Bot. Fr. xi. 51, t. 1. — Near Sorata, Province of Larecaja, altitude 

 2,090 to 3,000 meters, Mandon, no. 289. 



10. T. angustifolia, Benth. & Hook. f. Decumbent and rooting 

 at the nodes, pubescent: leaves lance-linear, acute, denticulate or entire: 

 iuvolucral scales acutish, pubescent or puberulent on the outer surface ; 

 the outer ones inclining to be squarrose : ligules oblong, 2 or 3 lines in 

 length. — Gen. ii. 392. — Collected in the Andes of Ecuador by Spruce, 

 no. 5582. 



§ 2. Involucral scales 2-3-seriate, less unequal ; the outer often her- 

 baceous and acutish. 



* Leaves ovate to linear, pubescent to densely hirsute but not canescent. 

 •t- Leaves relatively broad, subentire, toothed, or divided into a few rather 



broad lobes. 

 •w. Pappus longer than or about equalling the achenes. 



= Perennials with ligneous or lignescent base : rays short, nearly orbicular, 



3-tootiied. 



11. T. procumbens, L. More or less densely hirsute with white 

 hairs: stems several to many from a woody root or stock, decumbent or 

 procumbent : leaves lanceolate to ovate-lanceolate, acute, sharply repand- 

 or sinuate-toothed, cuneate at the base : scales of the involucre oblong, 

 acutish, usually villous-hirsute : chaff persistent: rays yellow or (?) white. 

 — Spec. ii. 900. Amellus pedunculatiis, Ovt. fide Willd. Enum. 916. 

 Balbisia elongata, Willd. Spec. iii. 2214. B. peduncidata, HofFmgg. Verz. 

 Pfl. 228. B. divancata, Cass. Ann. Sci. Nat. xxiii. (1831) 90. —The 

 most widely distributed species ; Monterey, North Mexico, Eaton 4* Ed- 

 wards, also Pringle, no. 1920; Wartenberg, near Tantoyuca, Ervendberg, 

 no. 61; San Luis Potosi, Parry ^ Palmer, no. 520; " Coahuila and 

 Nuevo Leon," Palmer, nos. 629, 20G1 ; Orizaba, Schaffner, Gray, Botteri; 

 Jalisco, Palmer, no. 297; Colima, Palmer, no. 1186; Oaxaca, L. O. 

 Smith, no. 423, E. W. Nelson, nos. 2582, 2773 ; Guatemala, nos. 2370, 

 & 4200 of Donnell Smith's sets. Also on Elliott's Key, Fla., Simpson, 

 no. 553; Cuba, Wright, no. 2861. Introduced and now abundant in E. 

 India and Mauritius. 



Var. ovatifolia. Less hirsute, pubescence shorter, finer, and tending 

 to become fuscous : base of stem ligneous : leaves ovate, acutish, serrate 

 with small subequal obtusish teeth, finely pubescent upon both surfaces, 

 8 to 10 lines long, 6 to 8 lines broad, rather abruptly contracted at the 

 base into short petioles : involucral bracts very broad, mostly obovate. — 

 Collected by E. W. Nelson in the vicinity of Yalalag, Oaxaca, July, 1894, 

 no. 948. Rather well marked in its foliage and possibly a distinct 



