32 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Collected by Dr. i. Palmer on river bottoms and mountain sides near Colima, 
January 9 to February 6, 1891 (no, 1209). 
In reporting upon Dr. Palmer’s Colima plants the writer referred this species to 
A. coulteri, Since then abundant material of the true coulteri has been collected by 
Mr. Nelson which shows this to be quite distinct. 
Acacia occidentalis Rose, sp. nov. 
A small tree or shrub, pubescent; petiole pubescent, bearing a gland above the 
middle; pinnie, 2 to 4 pairs; leaflets, 5 to 13 pairs, linear, 3 to 5 mm, long, at first 
puberulent, becoming glabrate in age, midyvein near the upper 
margin; flowers in heads, often 4 or more together, from the 
axils of the leaves; pods 7 cm. or less long, 2 cm. broad, stipitate, 
thin, glabrous. 
Only known from Sonora. 
Collected along railroad between Nogales and Guaymas by 
J. N. Rose, June 4, 1897 (no. 1294, type); near Altar, C. G. 
Pringle, April, 1884; Alamos, Dr. E. Palmer, 1890 (no. 315). 
This species has been distributed as a variety of A. malaco- 
phylla, but under a name which can not properly be used. [t 
is clearly not that species, differing especially in the size and 
veining of leaflets, texture of pods, ete. ; 
The species is very common on the dry plains of central Sonora. 
Here it appears as a low shrub, but doubtless because the largest 
plants have been cutaway. Dr. Palmer states that about Alamos 
it sometimes appears as a small tree, and that it is there much 
used as fuel. 
ce |} Acacia unijuga Rose, sp. nov. FIGure 8. 
A large tree with the wood white and very hard and durable; 
old branches grayish and glabrous; new branches pubescent; 
stipules spinescent, small in specimens seen; common petiole 
short, 2 em. or less long; pinne | pair; leaflets 2 pairs, oblong to 
orbicular, 2 to 4 em. long, rounded at apex sometimes mucronu- 
late, glabrous, midrib somewhat to one side; secondary rhachis 
narrowly winged; flowers small, yellow, in slen- 
der spikes (23 to 8 em. long), borne in clusters 
in the old leaf axils, peduncle bracteate at base; 
legume narrowly oblong, about 12 em. long, 1.8 
to 2.5 wide, acute at apex, stipitate at base, flat 
and thin. 
Collected by Mr. C. G. Pringle in the lowlands 
near Tampico in 1899 (no. 6989). One of the 
most common trees in the lowland forests from 
the Gulf coast to the edge of the table-land. 
Fig. 8—Pod of clea: Mr. Pringle states that this is a very useful 
cia unijuga. wood and is much used for railroad ties above 
Tampico. 
Mimosa hemiendyta Rose & Robinson, sp. nov. Fics. 9 anp 10. 
Shrub 3 to 6 meters high, with stiff, subflexuous, divaricate, terete 
branches, armed at the nodes with pairs of short, conical, reddish, Fig. 9—Pod of 
scarcely recurved thorns, and covered on one side by a short, dense, Mimosa hen- 
rufous tomentum, on the other side by a finer, less copious, at iendyta. 
length obsolete, gray tomentum,; petioles 3 to 10 mm. long, with 
similar bichromatic pubescence; leaf rachis 1.2 to 1.8 cm. long; pinne 4 pairs, 1.5 
to 2.5 cm. long; leaflets about 7 pairs, oblong, subtruncate at both ends, bright 
