190 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
14 mm. long, minutely pilose; pinnae 2 or 3 pairs, the leaflets 3 to 5 pairs, 
oval to broadly oblong, 7 to 14 mm, long, 8.5 to 7 mm. wide, rounded and 
oblique at the base, rounded at the apex, chartaceous or subcoriaceous, 
pilose with very short subappressed hairs or finally glabrate, green above, 
pale beneath, the margin plane; flowers capitate, sessile, the heads few- 
flowered, the peduncles 2.5 to 3 cm. long; calyx 7 to 8 mm. long, glabrous. the 
lobes oblong-ovate, variable in length, ciliate; corolla about 1.5 cm. long, copi- 
ously white-pilose above the calyx, the lobes lance-oblong, acute, about half as 
long as the tube; stamens very long, the tube exserted 1 to 1.5 cm. 
Type in the U. S. National Herbarium, no. 567316, collected at Salina Cruz, 
Oaxaca, Mexico, April 28, 1910, by C. R. Orcutt (no. 3288). 
Although the material at. hand is rather imperfect, this plant seems suffi- 
ciently distinct to deserve recognition as a species. It is related, evidently, to 
P. acatlense Benth., but in that the calyx is densely pilose, the peduncles are 
very short, and the numerous leaflets are much smaller and proportionately 
narrower, 
Pithecollobium calostachys Standl., sp. nov. 
Tree, 4.5 to 6 meters high or larger, the younger branches green or grayish, 
conspicuously lenticellate, pubescent at first, armed with numerous short, stout, 
ascending or subdivaricate spines; petioles 0.6 to 4.5 cm. long, slender, glabrous 
or nearly so, bearing a low gland at the apex; pinnae one pair, the rachis 0.6 
to 2.5 cm. long, the leaflets a single pair to each pinna, oblique, ovate to ob- 
long or oval-ovate, 3 to 11 cm, long, 1.8 to 6 cm. wide, rounded or obtuse at the 
base and very unequal, narrowed to the obtuse or acute apex, thick-chartaceous, 
bright green, glabrous or nearly so, the venation prominent or prominulous on 
both surfaces; inflorescence spicate, the spikes dense, 2.5 to 7.5 em. long, on 
long or short peduncles, axillary or usually paniculate, the rachis densely 
puberulent, the bracts linear-lanceolate, 2 to 8 mm. long, divaricate or reflexed, 
puberulent; calyx 2.5 to 3 mm. long, tubular-campanulate, pilose with minute, 
mostly appressed hairs; corolla 5 to 6 mm. long, sericeous, the lobes oblong- 
ovate, acute, about half as long as the tube; stamen tube much exserted, 
usually twice as long as the corolla or longer; fruit curved or coiled, glabrous, 
the valves 1.5 to 2 cm. wide, contorted after dehiscence, convex, very thick (6 
to 8 mm.) and hard. 
Type in the U. 8S. National Herbarium, no. 463247, collected in the vicinity of 
Tampico, Tamaulipas, Mexico, altitude about 15 meters, April, 1910, by Ed- 
ward Palmer (no. 307). 
The following additional specimens are in the National Herbarium: 
TAMAULIPAS: Tampico, Pringle 7681; May, 1910, Palmer. Gémez Farias, 
Palmer 282. 
San Luis Porosi: Tancanhuitz, alt. 860 meters, Nelson 4872. Without 
locality (perhaps from Tamaulipas), Palmer 1061. 
VeErRAcRkUz: Carrizal, Goldman 702, 703. 
TaBasco: Mayito, Rovirosa 112. 
Oaxaca: Chivela, Orcutt 8189, 
CHIAPAS: Tapachula, Nelson 3852. 
This plant has always been confused with P. lanceolatum (Humb. & Bonpl.) 
Benth. (P. ligustrinum Benth.), a species described from Venezuela. The lat- 
ter ranges northward from Venezuela and Colombia to Mexico, but in Mexico 
it is confined chiefly to the west coast, while P. calostachys is most abundant on 
the east coast. P. lanceolatum is distinguished from the species here described 
as new by the very short, triangular bracts and the included or short-exserted 
stamen tube. Its leaflets, too, are usually more obtuse at the apex, and the 
