Leucaena trichodes (Jacq.) Benth, Fabaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Mimosa trichodes Jacq.

Common name(s): [more details]

Spanish: arabisco, capra, chalón, chamba, chapra, miham, mihan, pela caballo, yerba de la lancha

Habit:  tree

Description:  "Small, sometimes multiple-stemmed tree or shrub, (1-) 3-10 (-15) m tall, 10-15 (-30) cm bole diameter, with upright angular branching and an open irregular narrow crown.  Bark pale to mid-grey-brown, smooth with pale brown, slightly raised, horizontally aligned lenticels on younger wood, and shallow vertical rusty orange-brown fissures on older boles, inner bark cream.  Shoots terete, pale grey-brown to rich mid-orange-brown, densely covered in short white velutinous pubescence or occasionally glabrous.  Stipules 2.8-3.1 mm long, lanceolate, long-pointed at apex, with a membranous basal asymmetric wing, early deciduous.  Leaves 13-22 (-29) cm long, 10-14 (-20) cm wide; petioles (including pulvinus) (16-) 20-40 (-50) mm long; rachis 6.5-13 cm long, with dense white velutinous pubescence, with a single, sessile, convex or conical, elliptical nectary, 2-3.5 mm long, 1.2-1.6 mm wide, on ventral side of petiole at base of the basal pair of pinnae, apex of rachis extending beyond the terminal pinnae as a pointed, curling, sparsely pubescent mucro 2.1-2.8 mm long; pinnae 2-3 (-4) pairs; pinnular rachis 4.6-8.2 (-11) cm long, densely pubescent, with 1 or 2 sessile, conical, elliptical nectaries, 0.4-0.7 x 0.3-0.4 mm, at base of terminal leaflet pairs on pinnular rachis; leaflets (1-) 2-4 (-6) pairs per pinna, (22-) 28-60 (-118) mm long, (10-) 15-50 (-71) mm wide, short-petiolate, very slightly asymmetric, acute or cuneate at base, ovate-elliptic, apex variably acute or obtuse, sometimes rounded, entire, ciliate on margins, pubescence variable, sometimes densely pilose, sometimes sparse and occasionally glabrous, slightly discolorous, mid-green above, paler below, midrib and secondary venation visible on both surfaces, secondary venation brochidodromous, tertiary venation reticulate.  Capitula 8-12 mm in diameter at anthesis, in fascicles of 3-5 in leaf axils on actively growing shoots, sometimes with suppression of the leaves on the flowering shoot and sometimes with once-branched flowering shoots, each capitulum with 90-170 flowers; peduncles variable, (6-) 10-18 mm long, angled, sparsely or densely pubescent, with an involucre of basally united bracts at distal end.  Flowers subtended by small peltate bracts, 1.3-2.4 mm long, 1 mm in diameter, densely pilose; calyx 1.3-2.6 mm long, sparsely hairy on lobe tips, pale whitish green; petals 2.3-3.3 mm long, free, with short pubescence on lobes, pale green; filaments 4-6.2 mm long, creamy white; anthers long-pilose, the hairs concentrated on the ventral side along the stomial furrow, cream-white, the connective with a pronounced dorsiventrally flattened "hooded" protrusion or spiculum; ovary 1.1-1.8 mm long, glabrous, pale cream-white, with 12-16 ovules, style 4.5-6 (-7.4) mm long, cream-white, with a narrow-funnelform stigma, held level with or slightly exserted beyond anthers.  Pods 1-3 (-4) per capitulum, (7-) 11-18 cm long, 18-24 mm wide, pendulous, with a short stipe, linear-oblong, cuneate at base and apex, often with a short beak at apex, flattened, 10-14-seeded, valves thin, chartaceous or membranous, variably glabrous and slightly lustrous or with dense velutinous pubescence, green or dark maroon when unripe, turning mid-reddish or orange-brown, the margins slightly raised, dehiscent along both sutures.  Seeds 6.1-8.2 mm long, 4-5.8 mm wide, compressed, elliptic or circular, deep chestnut-brown, glossy, aligned transversely in pods; pleurogram visible, regular, U-shaped, 90-95%, symmetrical" (Hughes, 1998; pp. 186-191).

Habitat/ecology:  In its native habitat in South America, "occurs primarily in dry deciduous tropical forest and dry thorn forest" (Hughes, 1998; pp. 186-191).

Propagation:  Seed

Native range:  Northern costal regions of Colombia and Venezuela and in the coastal provinces of Ecuador and Peru as far south as 13 degrees South. Occurs on the island of Hispaniola, but it is not certain whether it is native or an early introduction (pre-1821) and subsequent naturalization and spread (Hughes, 1998; pp. 186-191).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Ecuador (Galápagos Islands) Isabela Group	Isabela Island	introduced invasive cultivated	Charles Darwin Foundation (2008) Observed in survey, no herbarium record.
Ecuador (Galápagos Islands) San Cristóbal Group	San Cristóbal Island	introduced invasive cultivated	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Santa Cruz Group	Santa Cruz Island	introduced invasive cultivated	Charles Darwin Foundation (2008)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
South America (Pacific rim) South America (Pacific rim)	Colombia	native	U.S. Dept. Agr., Agr. Res. Serv. (2013) Bolivar, Magdalena
South America (Pacific rim) South America (Pacific rim)	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
South America (Pacific rim) South America (Pacific rim)	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Control:  If you know of control methods for Leucaena trichodes, please let us know.