ROSE—MEXICAN AND CENTRAL AMERICAN PLANTS. 27 
9. Argemone stenopetala (Prain) Rose, 
Argemone intermedia stenopetala Prain, Journ, Bot, 33: 364. 1895. 
Stems apparently annual, glaucous, and with scattered weak prickles, flowers sub- 
sessile, very small, white; petals lanceolate, 1.5 to 2 mm. long; fruit ovate-oblong, 
2.5 to 3em. long, prickly; style short. 
Specimens examined: 
Chihuahua: In valley near Chihuahua City, C. G. Pringle, 1885 (no, 43) ; same 
locality, J. N. Rose, 1899 (no. 4206). 
The writer found this species growing associated with A. echrolenea, from which it 
is dithicult to distinguish it except by the color of the flowers. 
Type locality: “Chihuahua City.” 
10. Argemone munita Dur. & Hilg. Pac. R. Rep, 5°: 6. pl. 7. 1855, 
Type locality: ‘Williamson Pass,’? California. 
The writer has not examined the type of A. wumita and the following specimens 
may belong elsewhere. They are quite different, however, from all our other Mexican 
material. 
Specimens examined : 
Sonora: Between Nogales and Guaymas, J. N. Rose, June 4, 1897 (no, 1299). 
Chihuahua: St. Diego, C. V. Hartman, May 8, 1891 (no. 673); Casas Grandes, 
I. A. Goldman, May 29, 1899 (no, 416). 
The writer found this species very common along the railroad running between 
Nogales and Guaymas. The large pure white flowers are often 8.5 em, in diameter. 
11. Argemone gracilenta Greene, Pittonia 3 : 346, 1898. 
A slender plant; branches pale, armed with scattered long slender prickles; leaves 
slightly lobed, very prickly; flowers sessile or nearly so; sepals broad, prickly on 
the back and terminating in a long prickle; petals white, 3 cm. long; fruit seen 
immature, oblong, prickly; style very short. 
Only known from Dr. E. Palmer’s plant from Lower California, collected in 1887. 
Type locality: ‘‘Muleje, Lower California.”’ 
Professor Greene says it is a ‘species of well-defined aspect and indisputable 
characters.” 
RANUNCULACEAE. 
NEW SPECIES OF THALICTRUM. 
Since my notes on some Mexican species of Thalictrum were pub- 
lished in volume 5 of the Contributions, I have given further attention 
to the genus, both in the field and in the study. Although considerable 
work must yet be done on our Mexican species, the following do not 
seem to be involved in the confusion and their publication need not be 
delayed longer. 
Thalictrum obliquum Rose, sp. nov. 
Stems slender, much branched above, glaucous, glabrous throughout, including the 
leaflets; leaves 3 or 4 times ternate, broad in outline; leaflets small, nearly orbicular 
or ovate, few-toothed or lacerate above, obliquely truncate, sometimes cuneate, the 
terminal ones sometimes cordate at base; inflorescence a narrow panicle; stamens 
shortly apiculate; akenes strongly reticulate-nerved, glabrous. 
Collected by C. G. Pringle on bluffs at Amozoc, Puebla, September 10, 1901 (no. 
9541). 
I should assign this species to a position near 7. gibbosum, but the leaflets are more 
deeply cleft and greener beneath, and the anthers distinctly but shortly apiculate. 
