188 UNITED STATES AND MEXICAN BOUNDARY. 
EUPHORBIA SERRULA (nov. spec.): patula seu decumbens; caule patenter piloso ; foliis e basi 
valde obliquo obtusiuscuia seu subcordata oblongis sepe falcatis obtusis argute grosseque 
serratis, subtus pilosis; stipulis lanceolatis laciniatis ; glomerulis lateralibus appendicibus 
angustis integris seu crenulatis; stylis ovario glabro brevioribus patulis ad basis fere bifidis ; 
seminibus ovatis levibus costato-angulatis. Western Texas and New Mexico. (No. 658, 1843 
and 1844, Wright. No. 796 and 804, Fendler.) ‘Stems 4-6 inches long. Leaves 3-5 lines 
long, 1-3 lines broad, sharply and coarsely serrate; seeds larger than in all the foregoing 
species, 0.8 line long, remarkably angled. - 
EUPHORBIA VILLIFERA, Scheele in Linnea 22, p. 153. Western Texas; Berlandier, 2084: 
Lindheimer, 530; Wright, Thurber. In various parts of Mexico; Gregg. Root annual, stems 
erect, often a foot high. 
EUPHORBIA HYPERICIFOLIA, Linn. Sp. 1, p. 454. New Mexico; Wright. (No. 1842 in part ) 
Chihuahua ; Thurber. The true Linnæan plant probably comes from the West Indies and 
other tropical countries, and has also been sent from Florida by Dr. Chapman. It is distin- 
guished by smaller anthodia, generally disposed in denser clusters, smaller capsules and smaller 
paler seeds. The common North American form, which has also been collected abundantly 
along the boundary, has larger and more scattered anthodia, larger capsules and larger blackish 
seeds, and may be distinguished as var. communis, as it seems to be the more common form 
throughout the warmer countries around the whole globe. 
EUPHORBIA PILULIFERA, Linn. 8 DISCOLOR: diffusa ; foliis e basi valde obliqua ovatis subrhom- 
boideis acutiusculus serratis, purpureo-maculatis, stipulis subulatis, capsula parvula pilosa, 
seminibus minutis ovatis acutis undulato-tuberculatis. Sonora; Thurber. Wright, No. 1842, 
in part. Mr. Blodgett found it in Florida. Stems j-1 foot long. Leaves 1-14 inch long; 
differs in shape and color of leaves from the usual forms of E. pilulifera ; hair of the stem as 
in all forms of this species yellow and jointed ; involucre only š line long; heads 3-1 lines in 
diameter; seed scarcely more than } line long. 
EUPHORBIA CAPITELLATA (nov. spec.) : annua, erectiuscula seu demum diffusa ; caulibus elonga- 
tis puberulis; foliis e basi valde obliqua oblongo linearibus subnudis argute serrulatis mucronatis ; 
stipulis lanceolatis laceris; glomerulis densifloris terminalibus fere aphyllis; involucri glandulis 
longius stipitatis, appendiculis orbiculatis s. late obovatis integris ; stylis ovario hirto longio- 
ribus ad medium bifidis; stigmatibus filiformibus divaricatis; capsula puberula; seminibus 
ovatis acutatis angulatis rugoso-tuberculatis. Valleys at San Bernardino, Sonora; Wright, 
(No. 1,849.) Stems 6—10 inches long; leaves 6-8 lines long, 2 lines wide; heads white, showy, 
4-6 lines in diameter. 
EUPHORBIA PYCNANTHEMA (nov. spec.): perennis, erecto patula, canescente-pubescens ; foliis e 
basi lata obliqua cordata ovatis s. oblongis obtusiusculis вере mucronulatis integris s. subserru- 
latis, scabris ; stipulis lanceolatis fissis ; glomerulis terminalibus multifloris quasi involucratis ; 
| involucris pilosulis (primariis) late orbiculato-appendiculatis seu (secundariis) subnudis ; stylis 
` fere ad basis fissis patulis ; stigmatibus divaricatis clavellatis ; capsula subglobosa pubescente ; 
seminibus acute angulatis transverse rugulosis punctatisque. Mountain sides near Lake Santa 
Maria, Chihuahua; Wright. Numerous stems 6 inches high, from a thick ligneous root; leaves 
4-5 lines long. General appearance of a small labiate plant with terminal involucrate heads. 
. 
x for the different involucres on the same head, reminding one of Hydrangea or some Um 
эээ EUPHORBIA LATA. E. DILATATA, Torr. & Cron Bot. Зон 8 Rep. р. 19; поп Hochst 
: similar i in many respects to the last, but more erect, more hairy, leaves shorter. Бары 
