GREENMAN — MEXICAN PLANTS. 307 



broadly ovate or ovate-oblong, 9 to 11 mm. long, nearly as broad, convex 

 ou one surface, flat on the other with a short ridge near the base. — Col- 

 lected by streams. Valley of Mexico, 10 October, 1896, no. 6226. 



Stevia clinopodioides. An herbaceous perennial : roots fibrous, 

 clustered at the base of the stem: stems simple or nearly so, about 30 cm. 

 high, giving off at the base several slender horizontal subterranean 

 root-stocks, closely pubescent above and purple : leaves opposite below, 

 alternate above, spatulate, 24- to 4 cm. long, 6 to 10 mm. broad, obtuse 

 at the apex, gradually narrowed below to the subpetiolate base, callously 

 serrate along the upper half, entire below, appressed-puberulent on the 

 veins and on the upper surface near the margin, glandular-punctate : in- 

 florescence a compact dense umbel terminating the stems : heads about 

 1 cm. long, o-flowered ; involucral scales linear-acuminate, often slightly 

 unequal, appressed-puberulent on the outer surface, greenish purple, 6 to 

 7 mm. long : flowers considerably exceeding the involucre : corolla with 

 a slender greenish tube below, ampliated above, the upper ampliated 

 portion and the limb purple ; pappus paleaceous, short, exaristate : 

 achenes glabrous, 3 to 4 mm. long. — Collected by C. G. Pringle, on the 

 Serrania de Ajusco, altitude 3,000 m., 22 October, 1896, no. 6594. 



Stevia diffusa. Annual : roots fibrous : stems herbaceous, erect, te- 

 rete, greenish purple, hirsutish pubescent with jointed hairs, interspersed 

 above with a stipitate glandular pubescence : leaves (including the petiole) 

 3 to 7 cm. long, 1 to 4 cm. broad, opposite below, becoming alternate above, 

 membranous, broadly ovate to ovate-lanceolate (the uppermost often 

 acuminate), acute at the apex, contracted below into a narrowly winged 

 and ciliated petiole, crenate-serrate, or the more reduced leaves with a 

 subentire margin, essentially glabrous upon either surface, except on 

 the veins, where they are sparingly hirtellous : heads widely separated 

 on long slender glandular pedicels, the latter from 1 to 1^ cm. long; 

 scales of the involucre 5, linear, acuminate, 6 mm. long, rather strongly 

 2-nerved, the outer surface appressed-puberulent, very rarely glandular : 

 flowers one third longer than the involucre: corolla discolorous, tube 

 purplish, puberulent, limb white : achenes puberulent, 3 mm. long: pap- 

 pus paleaceous and 3-aristate. — Collected by C. G. Pringle, on lava beds 

 near Cuernavaca, altitude 2,100 m., 3 November, 1896, no. 6608. Per- 

 haps related to S. micrantha. Lag., but with longer corollas, shorter 

 achenes, and a much more diffuse habit. 



Stevia trachelioides, DC. It is interesting to note that Mr. 

 Pringle has rediscovered this apparently rare species on the Serrania 

 de Ajusco, altitude 3,000 m., 22 October, 1896, no. 6593, where specimens 



