ROBINSON. — SPERMATOPHYTES OF MEXICO, 475 
branches, elliptic-ovate, acute or acutish at each end, short-petioled, 
sharply serrate, green, resinous-dotted, and pubescent on the upper sur- 
face, slightly paler and pubescent upon the pinnately arranged veins 
beneath: flowers in short few-flowered axillary cymes : calyx-lobes ovate, 
caudate-acuminate, externally pubescent toward the sharp tip, 4 mm. 
long: corolla bright scarlet, 1.2 em. long, with cylindrical tube and 4 
short rounded subequal lobes, the upper one broader and emarginate. — 
Collected by C. G. Pringle on the Sierra de Tepoxtlan, State of 
Morelos, Mexico, altitude 2,300 m., 11 September, 1900, no. 9445. 
Readily distinguished from all the other species by the callosities on 
the rib-like angles of its stems. 
Piqueria pyramidalis. Stem terete, 2 to 2.5 m. high, puberulent, 
green but maculate with elongated dark brown or purplish dots: leaves 
alternate (at least the upper ones), petiolate, broadly ovate, shallowly 
about 7-lobed, coarsely crenate, 3-nerved from the rounded to strongly 
cordate base, green and scabrous-puberulent above, paler and tomentulose 
beneath, the larger 1.7 dm. long and about as broad; petioles subterete, 
tomentulose: small and very numerous heads in pedicellate racemose 
glomerules ; these forming a large leafy-bracted pyramidal panicle : in- 
volucral scales oblong, green, about 2-seriate, 2.5 to 3 mm. long, puberu- 
lent and covered with minute amber-colored particles upon the outer 
surface: corolla white, 3 mm. long, with short proper tube and relatively 
large throat, also bearing a few amber-colored particles: styles much 
exserted, clavate, purplish or brown; achenes dark-colored, glabrous, 
lucid, 2.5 mm. long. — Collected by C. G. Pringle in shade of cliffs on 
mountains above Iguala, altitude 1,230 m., 10 October, 1900, no. 8389. 
Type in herb. Gray. This species, although possessing all the technical 
characters of the genus, differs considerably in habit from the other Mex- 
ican species, being in fact nearer some of the South American. 
Ageratum lucidum. Shrub with buff cortex and opposite spread- 
ing curved-ascending terete finely striate glandular-puberulent branches : 
leaves opposite, ovate, acutish, serrate from below the middle, thin, veiny, 
glabrous or early and completely glabrate upon both surfaces and lucid 
especially above, 4 em. long, half as broad, ciliolate upon the margin, 
3-nerved from somewhat above the abruptly acuminate shortly petiolate 
base, minutely white-dotted beneath and also covered with globular 
resinous or glandular atoms: corymbs long-peduncled (often irregularly 
compound), 2~6-headed and subtended by reduced opposite lance-oblong 
to linear sessile bracts; pedicels 1 to 2.4 cm. long, curved-ascending, 
l-headed with or without 1 or more filiform bractlets ; heads campanu- 
