NOVITATES OCCIDENTALES. 151 
exceeding the bracts of the involucre and nearly as long as 
the broadish and relatively short limb: achenes small 
(barely a line long); pappus-bristles few, very slender, fragile 
or deciduous. 
Common in certain districts of middle Mexico; Pringle’s 
n. 4353 from Jalisco, etc., distributed as a variety of LH. 
occidentale, from which it differs not only in habit, style of 
inflorescence, and color of flowers, but in the relative pro- 
portions of the tube and limb of the corolla, and in good 
characters of achene and pappus. We take pleasure in 
dedicating it to one of the more recent contributors to 
Mexican phytography, Dr. B. L. Robinson. 
Apocynum floribundum. Glabrous, pallid and glaucous, 
2 feet high, with numerous ascending and somewhat fastigiate 
branches rising to about the same level, each ending in a 
cyme: leaves about 2 inches long, from ovate to elliptical, 
mucronate, the margins sparsely serrulate-scabrous: cymes 
not dense, many-flowered, erect: corollas erect, lurid-purplish, 
nearly cylindrical, the lobes erect, or only a little spreading. 
Dry ground bordering pine woods, in the higher moun- 
tains west of the Mohave Desert, in Kern OCo., Calif., 1889. 
Nearest A. cannabinum, but of very different habit; the 
fastigiate branches, each with its own many-flowered cyme, 
uniting to-form a compound corymb often a foot broad. 
A. cannabinum, common in many parts of California, was 
found in wet ground by streamlets, in the same region, and 
true to its character, the dense terminal cyme of small 
greenish flowers, being greatly surpassed by those of the 
single pair of lateral branches. 
Asclepias tithymaloides. Suffrutescent, slender, 2 feet 
high, very light green, glabrous, the leafy branchlets with 
very short internodes: leaves opposite, divaricately spread- 
ing, 2 inches long or more, short-petioled, narrowly linear, 
tapering to each end, scarcely more than a line wide: umbels 
loose, 3 to 10-flowered, on peduncles less than an inch long; 
the pedicels as long: corolla greenish white, the lanceolate- 
