95 
1, G.triacanthos L. Thorns stout, often triple or compound: leaflets lanceolate- 
oblong, somewhat serrate: pods linear, elongated, 30 to 45 em. long, often twisted, 
filled with sweet pulp between the seeds.—An Atlantic species, extending at least to 
the valley of the Brazos in ‘Texas, and common in cultivation. 
44. PROSOPIS L. (Mezquirt. SCREW-BEAN.) 
Trees or shrubs, often armed with axillary spines or spinescent stip- 
ules, with bipinnate leaves, 1 or 2 pairs of pinne, usually numerous 
small entire leaflets, small greenish flowers in cylindrical or globose 
axillary pedunculate spikes, and a linear pod which is compressed or 
terete, straight or faleate or twisted, coriaceous and indehiscent, and 
with thick partitions between the seeds. 
* Pod elongated, straight or faleate : spines axillary: spikes cylindrical. 
1, P, juliflora DC. (Mezquit.) Shrub or tree, glabrous or puberulent, with stout 
axillary spines or unarmed: leatlets 6 to 30 pairs, short-oblong to linear, obtuse or 
acute, 6 to 36 mm. long: spikes 5 to 10 em. long, usually dense, 1 to 3-fruited: pod 
stipitate, 10 to 15 cm. long or more, acuminate, at length sweet and pulpy within.— 
The chief woody plant of the wooded table-lands and high valleys throughout south- 
ern and western Texas, often forming impenetrable thickets. Exceedingly useful for 
fuel, for a gum it yields, and also as an article of food, the ripe bean being one of the 
staple foods of Mexicans, Indians, and grazing animals, 
** Pod thick and spirally twisted in numerous turns : stipules spinescent: spikes globose 
to cylindrical. 
2. P. pubescens Benth. (SCREW-BEAN. TORNILLO.) A shrub or small tree, resem- 
bling the last, canescently puberulent or glabrate : leaflets 5 to 8 pairs, oblong, acut- 
ish, 6 to8 mm. long: spikes lax, 3.5 to 5 cm. long, on peduncles about equaling the 
leaves: pod twisted into a narrow straight cylinder 2.5 to 5 cm. long, pulpy within, 
nearly sessile.-—Abundant along the Rio Grande and many of its tributaries from El 
Paso to Devil’s River. The pod used as food by Mexicans and Indians. 
3. P. cinerascens Gray. A similar species with similar fruit, but with the leaves 
and leaflets much smaller, the common petiole nearly obsolete, the slender spines 
usually exceeding the leaves, and the flowers in long peduncled globose heads.— Along 
or near the Lower Rio Grande. 
45. NEPTUNIA Lour. 
Perennial herbs or shrubby plants, diffuse, prostrate, or floating, 
with bipinnate leaves, small leaflets, yellow flowers in globose heads on 
solitary axillary peduncles, anthers crowned with a stipitate gland, and 
an obliquely-oblong, flat, two-valved pod deflexed from the stipe. 
}. N. lutea Benth. Pubescent and prostrate, with elongated branches: pinna 3 
to 5 pairs; leaflets 15 to 20 pairs, linear-oblong, mucronate, ciliate, much crowded, 
veiny beneath: peduncles longer than the leaves: heads many-flowered, nodding : 
pod 3 to 8-seeded, very obtuse, on a rather long stipe.—In eastern and southern 
Texas, extending as far up the Rio Grande as Eagle Pass. 
2, N. pubescens Benth. Closely resembling the last, but pinne 2 or 3 pairs, leaf- 
Jets 20 to 30 pairs, flower-heads much smaller, and the stipe of the pod scarcely ever 
over 2 mm. long,—Between the Guadalupe and Rio Grande as far up as Eagle Pass. 
3. N. tenuis Benth. Almost glabrous, diffuse, with slender branches: pinne 2 to 
4 pairs; leatlets 10 to 15 pairs, oblong-linear, about 4 mm. long: pod long-stipitate,— 
Jy eastern Texas, and possibly within our range, 
