Albizia

Taxonomy

Albizia A. Durazzini Mag. Tosc. 3(4): 13. 1772.

Subfamily: Mimosoideae.
Phylogenetic Number: 2.5.03.
Tribe: Ingeae.
Species Studied - Species in Genus: 38 studied; 100–150 in genus (19 native to the New World).

Description

Fruit: A legume, or a loment (or a loment segment); unilocular; (4–)5–42 cm long; 0.5–7 cm wide; 0.1–1 cm thick; 2–9 times longer than wide, or more than 9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with deciduous calyx; without orifice formed by curving of fruit or fruit segments; straight to 0.5-coiled to 1-coiled; not plicate; not twisted, or twisted (slightly); asymmetrical, or symmetrical; broadly linear to oblong, or falcate, or C-shaped; with both sutures parallelly curved; not inflated; compressed to flattened; without beak, or with beak (rarely); straight; with solid beak the same color and texture as fruit; rounded at apex to short tapered at apex, or truncate at apex, or abruptly long acuminate at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit (rarely); short tapered at base, or rounded at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit (rarely); with the apex and base uniform in texture; coriaceous to chartaceous, or ligneous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin not constricted to constricted; margin constricted along both margins, or constricted only on 1 margin (dorsal margin); margin without sulcus; margin plain, or embellished; margin with thickened sutural areas; wing(s) absent; stipitate, or substipitate to nonstipitate; with the stipe 1–20 mm long; with all layers dehiscing (or tardily dehiscent), or indehiscent; splitting along suture(s). Dehiscence of valves along 1 suture (ventral margin), or both sutures; medial and up and down; active (if indehiscent, remaining entire to breaking through sutures into 1-seeded segments or occasionally breaking irregularly or falling from replum); with valves reflexing. Replum invisible, or visible (rarely). Loment an intact article; indehiscent; segments (articles) conspicuous, or inconspicuous; segments (articles) 5–15 mm long; segments (articles) widest across seed area; segments (articles) with apical 1 different shape than middle one(s) and basal 1 different shape than middle one(s); segments (articles) D-shaped, or oblong, or rectangular, or trapezoid. Epicarp dull to glossy; monochrome; brown (or yellowish brown), or tan; with surface texture uniform; glabrous to pubescent and indurate; with hairs erect; with 1 type of pubescence; puberulent; with pubescence brown; with pubescence uniformly distributed, or pubescence denser near sutures, sparser centrally; with simple hairs (straight); pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; veined; transversely veined relative to fruit length, or reticulately veined; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp absent, or present; thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; spongy; chartaceous. Endocarp present; visible; dull; opaque; monochrome; white to tan; smooth; without adhering pieces of testa; septate to nonseptate; with septa thin (tissue paper-like), flexible, or thicker than paper, firm; with septa eglandular; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; remaining fused to epicarp; without wings; entire. Seed(s) 8–26; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 2–15 mm long; of 1 length only; filiform to thick; curved to coiled (spirally), or plicate. Aril absent.

Seed: 3–22 mm long; 2–15 mm wide; 1–9 mm thick; not overgrown; not angular; symmetrical; circular to ovate, or elliptic, or oblong; compressed to flattened; with surface smooth; without visible radicle and cotyledon lobes; with shallow hilar sinus, or without hilar sinus; without umbo on seed faces; without medial ridge on each face. Cuticle not exfoliating; not inflated; not wrinkled. Testa present; without pieces of adhering epicarp; not adhering to endocarp; free from endocarp; glossy, or dull; not modified by a bloom; colored; monochrome; brown to tan to black; glabrous; smooth; coriaceous to osseous. Pleurogram present; 50–100 %. Pseudopleurogram absent. Fracture lines present, or absent; reticulate (within pleurogram). Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible, or fully concealed; concealed by funicular remnant; without faboid split; punctiform; subapical to radicle tip to marginal according to radicle tip (not to embryonic axis); recessed; not within corona, halo, or rim, or within halo; halo darker than testa. Lens discernible; 1–5 mm long; with margins straight, or curved; linear; elliptic; not in groove of raphe; adjacent to hilum; 0.5–2 mm from hilum; mounded to flush; similar color as testa, or dissimilar color from testa; lighter than testa; tan; not within corona, halo, or rim. Endosperm absent, or present; thin; not pluglike and not resembling tip of radicle; covering entire embryo, or covering at least 1/2 of embryo, but not entire embryo; adnate to testa. Cotyledons smooth; both outer faces flat; both the same thickness; both more or less of equal length, or 1 longer than other; not folded; margin entire 180 degrees from base of radicle; similar at apex; partially concealing radicle; split over radicle; with lobes; with lobes overlapping; with basal groin formed by lobes, or without basal groin formed by lobes; with the interface division terminating at base of radicle; without margins recessed; tan; inner face flat; glabrous on inner face. Embryonic axis straight; parallel to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose; lobe tip straight; straight with embryonic axis; centered between cotyledons; less than 1/2 length of cotyledons, or 1/2 to nearly length of cotyledons. Plumule well developed; glabrous.

Distribution

Pantropic and pansubtropic.

New World and Old World; pantropical and pansubtropical; Mexico, West Indies, Central America, and South America; Argentina, Peru, Brazil, Ecuador, and the Guianas; southern China, Russia, Africa, Madagascar, Southwest Asia, India, Indochina, Indonesia and the Philippines, Australia, Pacific, New Guinea, Fiji, and Korea.

Generic Notes

The circumscription of Albizia used here is very different for the New World and Old World species. Barneby and Grimes (1996) employed a restricted circumscription of the genus for the New World species, and therefore had a number of segregate genera, including among others Chloroleucon (2.5.12) and Pseudosamanea (2.5.04B). Consequently according to Barneby and Grimes, there are only nineteen native Albizia species in the New World. Nielsen (1979b, 1985a, 1985b, 1992a), on the other hand has used a much broader generic concept for Albizia in the Old World, especially southeast Asia and Malesia. Therefore the variability evident in our data results from the Old World species examined, and the New World species are, in general, less variable than the Old World ones. Albizia section Lophantha series Pachyspermae is now Paraserianthes, 5.10. Nielsen (1979b) in a study of the Albizia spp. of mainland southeastern Asia diagramed their seeds and presented a fruit-plant key.