1. PITHECOLOBIUM Mart.
Trees or shrubs, with slender branches armed with the persistent spinescent stipules. Leaves petiolate, bipinnate, the pinnæ few-foliolate, their rachis generally marked by numerous glands between the pinnæ and between the leaflets. Flowers perfect or polygamous, from the axils of minute bracts, in pedunculate globose heads or oblong cylindric spikes, their peduncles in terminal panicles or axillary fascicles; calyx campanulate, short-toothed; corolla funnel-shaped, the petals as many as the teeth of the calyx, joined for more than half their length; stamens numerous, united at base into a tube free from the corolla; anthers minute, versatile; ovary stipitate, contracted into a slender filiform style, with a minute terminal stigma. Legume compressed, 2-valved, dehiscent, the valves continuous or interrupted within. Seeds compressed, suspended transversely; funicle filiform or expanded into a fleshy aril; hilum near the base of the seed; seed-coat thin or thick, marked on each of the 2 surfaces of the seed by a faint oval ring or oblong depression; embryo filling the cavity of the seed; the radicle included or slightly exserted.
Pithecolobium with more than a hundred species is widely distributed through the tropical and subtropical regions of the two worlds, and is most abundant in tropical America. Of the four species found within the territory of the United States three are arborescent.
The generic name, from πίθηξ and ἐλλὸβίον, relates to the contorted fruit of some of the species.
CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES.
Pinnæ with 1 pair of leaflets; valves of the legume much contorted after opening; seed surrounded by the enlarged ariloid funicle.1. [P. unguis-cati] (D). Pinnæ with more than 1 pair of leaflets; valves of the legume not contorted after opening; funicle of the seed not enlarged and ariloid. Pinnæ with 3—5 pairs of leaflets; legume short-stalked, the valves submembranaceous; seeds not in separate compartments.2. [P. brevifolium] (E). Pinnæ with 2—3 pairs of leaflets; legume sessile, the valves thick and woody, tardily dehiscent; seeds in separate compartments.3. [P. flexicaule] (E).
1. [Pithecolobium unguis-cati] Mart. Cat’s Claw.
Zygia Unguis-Cati Sudw.
Leaves persistent, long-petiolate, with a single pair of bifoliolate pinnæ and a slender petiole ½′—1′ long and slightly and abruptly enlarged at base; rachis glandular between the short stout petiolules and between the orbicular or broad-oblong leaflets, rounded and rarely emarginate at apex, rounded on one side and cuneate on the other of the oblique base, entire, thin or somewhat coriaceous, reticulate-veined, bright green and lustrous on the upper surface and paler on the lower surface, ½′—2′ long, and ½′—1½′ wide. Flowers polygamous, pale yellow, glabrous or slightly puberulous, opening in Florida in March and continuing to appear until midsummer, in globular heads on slender peduncles 1′—1½′ long fascicled in the axils of upper leaves or collected in ample terminal panicles, their bracts lanceolate, acuminate, chartaceous, ¼′ long, caducous; calyx rather less than 1/12′ long, broadly toothed, one quarter as long as the acuminate petals barely exceeding the tube formed by the union of the filaments; stamens purple, ½′ long; ovary glabrous, long-stalked, minute or rudimentary in the sterile flower. Fruit slightly torulose, stipitate, rounded or acute at apex, 2′—4′ long, ¼′—½′ wide, the valves reticulate-veined, thickened on the margins, bright reddish brown and after opening greatly and variously contorted; seeds irregularly obovoid or sometimes nearly triangular, compressed or thickened, dark chestnut-brown, lustrous, marked by faint oval rings, ⅓′ long, surrounded at base by the enlarged bright red ariloid funicle; seed-coat thin, cartilaginous.
A tree, sometimes 20°—25° high, with a slender trunk 7′—8′ in diameter, ascending and spreading branches forming a low flat irregular head, and slender somewhat zigzag branchlets slightly striately angled when they first appear, becoming terete, light gray-brown or dark reddish brown, covered with minute pale lenticels, and armed with the straight persistent rigid stipular spines broad at base and ¼′ long, or rarely minute; more often a shrub, with many vine-like almost prostrate stems. Bark of the trunk ¼′ thick, reddish brown and divided by shallow fissures into small square plates. Wood very heavy, hard, close-grained, rich red varying to purple, with thin clear yellow sapwood. The bark is astringent and diuretic, and was once used in Jamaica as a cure for many diseases.
Distribution. Florida, Captive and Sanibel Islands and Caloosa, Lee County to the southern keys; most abundant in its arborescent form on the larger of the eastern keys, and probably of its largest size in Florida on Elliott’s Key; often forming shrubby thickets; on the Bahamas, and common and widely distributed through the Antilles to Venezuela and New Granada.
2. [Pithecolobium brevifolium] Benth. Huajillo.
Zygia brevifolia Sudw.
Leaves 2′—3′ long, 2′ wide, with eight to ten 10—20-foliolate pinnæ and slender terete petioles 1′ in length and furnished near the middle with a dark oblong gland, when they unfold coated with pale tomentum and at maturity glabrous with the exception of the puberulous petiole and rachis; persistent or tardily deciduous; leaflets oblong-linear, obtuse or acute at apex, oblique at base, very short-petiolulate, light green on the upper surface, paler on the lower surface, ⅙′—¼′ long. Flowers white to violet-yellow, in globose or oblong heads ½′ in diameter, on thin pubescent peduncles bracteolate at apex, coated at first, like the flower-buds, with thick white tomentum, developed usually in pairs from the axils of lanceolate acute scarious deciduous bracts, and arranged in short terminal racemes; calyx shortly 5-lobed, puberulous on the outer surface, about 1/24′ long and one fourth the length of the puberulous petals persistent with the stamens at the base of the mature legume; stamens nearly ½′ long. Fruit ripening at midsummer and often persistent on the branches after opening until the trees flower the following year, straight, slightly torulose, short-stalked, contracted at apex into a short slender point, 4′—6′ long and ⅔′ wide, its valves thin, thick-margined, reddish brown on the outer surface, yellow tinged with red on the inner surface, reticulate-veined; seeds suspended by a slender coiled and somewhat dilated funicle, compressed, ovoid to nearly orbicular, dark chestnut-brown, very lustrous, ¼′ long, and faintly marked by large oval depressions; seed-coat thin, cartilaginous.
A tree, 25°—30° high, with a trunk rarely 5′—6′ in diameter, slender upright branches forming a narrow irregular head, and branchlets slightly striately angled, covered with minute white lenticels, light gray and puberulous when they first appear, becoming dark brown in their second year, and armed with stout rigid stipular spines sometimes ½′ long and persistent for many years; more often a shrub, sometimes only 2°—3° tall. Bark of the trunk smooth, light gray somewhat tinged with red, and often marked by large pale blotches. Wood dark-colored, hard, and heavy.
Distribution. Bluffs and bottom-lands of the lower Rio Grande, and on the upper Nueces River in Uvalde County, Texas; usually a low shrub spreading into broad clumps, but occasionally in the rich and comparatively moist soil of the banks of river-lagoons a slender tree; in Mexico more abundant, and of its largest size from the mouth of the Rio Grande to the Sierra Madre of Nuevo Leon.
3. [Pithecolobium flexicaule] Coult. Ebony.
Zygia flexicaulis Sudw.
Leaves persistent, 1½′—2′ long, 2½′—3′ wide, long-petiolate with slender puberulous petioles glandular near the middle and furnished at apex with small orbicular solitary glands, and 4—6 usually 6-foliolate pinnæ, the lowest pair often the shortest; leaflets oblong-ovate, rounded at apex, reticulate-veined, thin or subcoriaceous, glabrous, dark green and lustrous on the upper surface, paler on the lower surface, ¼′—⅓′ long; petiolules short and broad. Flowers light yellow or cream color, very fragrant, sessile in the axils of minute caducous bracts, appearing from June until August, in cylindric dense or interrupted spikes 1½′ long, on stout pubescent peduncles fascicled in the axils of the upper leaves of the previous year; corolla four or five times as long as the calyx and like it puberulous on the outer surface, and about as long as the tube formed by the union of the filaments; stamens ⅛′ long; ovary glabrous, sessile. Fruit ripening in the autumn and remaining on the branches until after the flowering season of the following year, sessile, tardily dehiscent, thick, straight or slightly falcate, oblique at base, rounded and contracted into a short broad point at apex, pubescent, 4′—6′ long and 1′—1¼′ wide, with thick woody valves lined with a thick pithy substance inclosing and separating the seeds; seeds suspended on a very short straight funicle, bright red-brown, ½′ long and ¼′ wide, irregularly obovoid, faintly marked by short oblong depressions; seed-coat thick, crustaceous.
A tree, 20°—30° high, with a straight trunk 2°—3° in diameter, separating 8°—10° from the ground into short spreading branches forming a wide round head, and stout zigzag branchlets, puberulous, light green or dark reddish brown when they first appear, becoming in their second year glabrous or rarely puberulous, dark reddish brown or light gray, and armed with the persistent stipular pale chestnut-brown spines ¼′—½′ long. Wood exceedingly heavy, hard, compact, close-grained, dark rich red-brown slightly tinged with purple, with thin clear bright yellow sapwood; almost indestructible in contact with the ground and largely used for fence-posts; valued by cabinet-makers and for fuel, and considered more valuable than that of any other tree of the lower Rio Grande valley. The seeds are palatable and nutritious, and are boiled when green or roasted when ripe by the Mexicans, who use their thick shells as a substitute for coffee.
Distribution. Shores of Matagorda Bay, Texas, to the Sierra Nevada of Nuevo Leon, and in Lower California; common on the bluffs of the Gulf-coast and on both banks of the lower Rio Grande; south of the Rio Grande one of the commonest and most beautiful trees of the region.