Albizia julibrissin Durazz.

  • Authors

    Rupert C. Barneby

  • Authority

    Barneby, Rupert C. & Grimes, James W. 1996. Silk tree, guanacaste, monkey's earring: a generic system for the synandrous Mimosaceae of the Americas. Part I. Abarema, Albizia, and allies. Mem. New York Bot. Gard. 74: 1-292.

  • Family

    Mimosaceae

  • Scientific Name

    Albizia julibrissin Durazz.

  • Type

    Described from a plant grown at Florence, raised from seed brought from Constantinople. — Neotypus (Nielsen, Adansonia 19: 206, 213, pl. 2. 1979): Herb. Micheli, s.n., FI (not seen).

  • Description

    Species Description - Amply microphyllidious, broad-crowned, unarmed, deciduous trees of rapid growth and early maturity, attaining 6-12 m but often precociously fertile, appearing glabrous but the lf- and some inflorescence-axes thinly (in var. mollis (Wallich) Bentham more densely) pilosulous with loose pallid hairs <0.5 mm, the foliage bicolored, the thin-textured lfts green and glabrous above, beneath paler and often thinly silky at least on anterior side of midrib, often ciliolate, the inflorescence a simple, abruptly flexuous, mostly efoliate, often at anthesis corymbiform pseudoraceme of capitula terminal to homotinous branchlets and surpassed by uppermost lvs, the overall branching-pattem sympodial. Stipules submembranous linear- lanceolate, caducous as the associated lf expands, absent from most specimens. Lf-formula (iv-)v-x (-xii)/19-30; lf-stks ±1-2 (in saplings -3.5) dm, petiole ±3-7 cm, the longer interpinnal segments 1-1.8 (-2.5) cm; petiolar nectary well below midpetiole sessile, round or elliptic, scutiform or shallowly patelliform 0.8-2.5 mm diam, a smaller nectary at tip of most lf-stks and yet smaller ones at tip of most pinna-rachises; pinnae decrescent proximally, scarcely so distally, the rachis of the penultimate pair 5.5-11 cm, the longer interfoliolar segments 2-4 mm; pulvinules 0.4—0.7 mm, not or scarcely wrinkled; lfts subequilong except at far ends of rachis, one or both of the first pair usually reduced to a paraphyllidium, the rest dimidiately narrow-oblong or lance-oblong from pos- tically subrectangular base, abruptly acuminulate or apiculate at erect or often incurved apex, those near midrachis 8-13.5 x 2.2-3.7 mm, 2.8-4.3 times as long as wide; venation palmate and then pinnate, the midrib forwardly displaced to divide blade 1 :(5—)6—10, the innermost of 2-3 posterior primary nerves incurved-ascending to anastomosis a little short of midblade, the outer one(s) shorter, the midrib giving rise on posterior side only to 2-4 weak secondary nerves and a faint reticulum of veinlets, the whole venulation either immersed or faintly prominulous on upper face, more sharply but finely raised beneath. Primary axis of inflorescence ±3-9 cm, efoliate throughout or sometimes foliate at the first 1-3 nodes, the peduncles solitary or 2-3 per node, those at proximal nodes longest, ±(2.5-)3-5 cm; capitula 12—20-fld, the fls dimorphic, the peripheral ones either sessile or contracted at base into a stout pedicel to 0.8 mm, all bisexual, the terminal ones always sessile, longer, functionally staminate, and the filament-tube far-exserted, sometimes one fl (or flowerless bract) downwardly displaced onto peduncle, the hemispherical receptacle commonly 1.5-2.5 mm diam; bracts linear-spatulate ±1 mm, quickly deciduous; the calyx of all fls submembranous, pale green, either glabrous ciliolate or thinly pilosulous, the greenish corolla externally silky- strigulose or pilosulous, at least on lobes; PERIPHERAL FLS: calyx campanulate or deeply campanulate 2.2-4.2 x 1.1-1.7 mm, the incurved, ovate obtuse or deltate teeth 0.3-0.7 mm; corolla slenderly trumpetshaped 7-11 mm, the erect ovate lobes 1.3-2.6 x 0.9-1.2 mm; androecium 24-34-merous, 24—38 mm, the stemonozone 1 mm or less, the tube 6.5-13 mm (a little shorter to 2 mm longer than corolla), at separation of the filaments 1 mm diam or less, the free part of filaments pink or pinkish orange; TERMINAL FL: calyx 3.5—4.5 x 2.2-2.8 mm; corolla ±9-11 mm; filament-tube 11-16.5 mm, at separation ±2 mm diam, internally thick-ribbed at base but without disc; ovary slenderly ellipsoid, compressed, attenuate at both ends, glabrous at anthesis; style filiform; ovules 10-14. Pods 1-3 per capitulum, in profile broad-linear straight 10-17.5 x 1.7-2.6 cm, attenuate at both ends, at base into a short or obscurely differentiated stipe, at apex into an erect cusp, piano-compressed, the papery, at first green, when ripe stramineous or fuscous-stramineous valves framed by obtuse sutures ±1 mm wide, bullate on each face over each seed, the cavity continuous; dehiscence inert, through both sutures, tardy, often delayed till after fall of fruit; seeds transverse, basifixed on sinuously filiform funicle, in broad view elliptic, compressed but plump, the brittle exotesta dull brown, charged on each face with a long U-shaped pleurogram, the lens convex, pallid, conspicuous.

    Local Names and Uses - Mimosa, silk-tree.

  • Discussion

    Albizia julibrissin lacks septate fibers in the wood (Chauhan & Dayal, 1985), a feature common in New World species.

  • Common Names

    mimosa, silk tree

  • Distribution

    Native in warm-temperate and subtropical Asia, widely planted and naturalized elsewhere in cool-winter, hot-summer climates. — Fl. midsummer.

    Asia|