OP ARfS AND SCIENCES. 107 



leaves thin, ovate, undivided or more or less hastately 3-lobed, callous- 

 denticulate, punctate on both surfaces, glabrous below, minutely pu- 

 bescent on the nerves and somewhat scabrous above, 1-2 inches in 

 length, acuminate and mucronate at the apex, deeply cordate at the 

 base with a rounded open biglandular sinus : glands stipitate, minute, 

 i-J line in diameter, on pedicels of equal length : tendrils slender, 

 simple : racemes 4-5 lines long : staminate flowers yellow, § line 

 broad . rather single, annular, horizontal : fruit ^ inch long, 4 lines 

 broad, very obli(pie and strongly curved, laterally compressed, acutely 

 beaked, armed with a few short weak spines ; the convex suture spi- 

 rally revohite in dehiscence. — Rocky hills near Patzcuaro, Michoacan, 

 October, 1892 (n. 4317). Near (7. biglandulifera, Cogn. (ex char.), 

 but with more simple tendrils and very much smaller glands. 



PiQUERiA LAXiFLORA. A Sparingly pubescent annual, 1^ feet 

 high : stem weak, furrowed, branching : leaves thin, lanceolate, nar- 

 rowed to an obtuse point, serrate, 3-nerved, 1^-2 inches long: peti- 

 oles 3 lines in length : branches slender, terminating in loose panicles 

 with flexuous filiform divisions: bracts minute, linear, 1-1 1 lines 

 long : pedicels fiUform, spreading, 3-6 lines in length : heads 4-flow- 

 ered : scales of the involucre 4 (2 narrower), thin, green, slightly 

 fringed above and mucronate : achenes black, 5-angled, 1 line long, 

 narrowed downward. — Cool slopes and ledges, Cafions of mountains 

 near Lake Chapala, Jalisco, November, 1892 (n. 4333). "Well char- 

 acterized by its very diffuse inflorescence, which suggests Valeriana 

 sorhifolia and allies. 



PiQUERiA Pringlei. Rhizome horizontal, branching, several 

 inches in length: stems subsiraple, slender, erect, purplish, 1-1 1 feet 

 high, with a fine grayish pubescence : leaves broadly ovate, an inch in 

 length, serrate, rather abrupt at the base, pubescent : petioles 3-4 

 lines long : inflorescence a rather dense irregular corymb : heads 2 lines 

 long, 4-flowered: scales of the involucre 4, obovate, lacerate above and 

 mucronate at the apex: corolla 1|^ lines long: filaments pubescent: 

 acheues glabrous, black, a line in length. — In pine woods, Nevado de 

 Toluca, September, 1892 (n. 4285). Habit of P. pilosa, HBK., but 

 differing in its well developed rhizome, in its leaves more abrupt at 

 the base, and its pubescent filaments. 



Stevia laxa. — Root of numerous strong fibres : stem erect from 

 a slightly decumbent base, about 2 feet high, purplish, terete, puberU' 

 lent, substriate, simple up to the lax finely glandular inflorescence : 

 leaves rather numerous below, opposite, ovate, acutish, crenate-serrate, 

 1-1^ inches long, nearly smooth, paler beneath, contracted below into 



