Albizia saman (Jacq.) F.Muell.,Select. Extra-Trop. Plants: 27 (1891)

Synonyms
Acacia propinqua A.Rich.
Albizzia saman (Jacq.) Merr.
Calliandra saman (Jacq.) Griseb.
Enterolobium saman (Jacq.) Prain
Feuilleea saman (Jacq.) Kuntze
Inga cinerea Willd.
Inga salutaris Kunth
Inga saman (Jacq.) Willd.
Mimosa pubifera Poir.
Mimosa saman Jacq.
Pithecellobium cinereum Benth.
Pithecellobium saman(Jacq.) Benth.
Pithecellobium saman var. saman
Samanea saman (Jacq.) Merr.
Zygia saman (Jacq.) A.Lyons

Description
Tree to 25 m, with a large crown spreading to 33 m in a complete canopy, diameter to at least 100 cm. Bark finely closely fissure-d, light grey or greyish brown. The sapwood is whitish, the heartwood dark chocolate-brown. Branchlets puberulous to tomentose. Leaves: rachis to 40 cm, with gland(s) just below the junction of the basal pair of pinnae and distally at all other pairs of pinnae, circular, concave, sessile, c. 0.5 mm in diameter; pinnae 3-9 pairs, to 11 cm, with glands at the junctions of the leaflets; leaflets 2-10 pairs per pinna, asymmetrically, ovate, elliptic or subrhomboid, base half rounded/ half truncate, apex rounded or obtuse, often emarginate and mucronulate; main vein diagonal, lateral veins densely reticulate, raised, upper surface glabrous, lower surface densely short-pubescent. Inflorescence: peduncles densely shortly yellowish pubescent, 2-5 together in the distal leaf-axils, 5-10 cm long, bearing a terminal corymb. Marginal flowers c. 3 cm, pedicellate; calyx funnel shaped, 5-7 mm, tomentose or woolly; teeth broadly triangular, acute, 0.5-1 mm; corolla red or yellowish-red, funnel-shaped, c. 10-12 mm, distal part tomentose or woolly; lobes triangular-ovate, c. 2 mm; stamens white at base, purple toward the top, 20-35 mm, tube shorter than the corolla-tube; ovary sessile, glabrous. Central flower sessile; corolla to 12 mm; staminal tube longer than the corolla. Pod black, oblong, 15-20 by 1.5-2.3 cm, inside transversely septate. Seeds brown, elliptic, strongly biconvex, c. 8 by 5 by 4 mm; areole elliptic, c. 7 by 3 mm. [from Flora Malesiana]

Ecology
Sandy, coastal areas; along roadsides, often planted; altitude 0-1800 m. During the night, and when the sky is overcast during the day, the leaves are hanging loosely down as in most other Mimosoids, hence its popular name Rain Tree. Another explanation for the name is the excretion of sugar-rich juice by extrafloral nectaries, which drops from the trees like rain.

Uses
The 'Rain Tree' is widely cultivated as an ornamental and together with the 'Ramboyant' (Delonix regia Raf.) belongs to the most common street trees; both are characterized by a broad umbrella- shaped crown. A good honey plant. Pods used as fodder for cattle, pigs and goats. The wood is used for furniture, general construction, boxes, crates etc., but is not durable.

Distribution
Native of northern tropical South America, now planted and appearing spontaneous all over the tropics.

Local names
Bengali: shirish.
English: saman, rain tree, monkey pod, giant thibet, inga saman, cow tamarind, East Indian walnut, soar, suar.
French: arbre a (la) pluie (rain tree).
Gujarati: shirish.
Hindi: vilaiti siris.
Indonesian/Malay: pukul lima (five o'clock tree, in Malaysia), pokok hujan (rain tree).
Javanese: trembesi.
Kannada: Bhagaya mara.
Malayalam: chakkarakkay maram.
Marathi: vilayati shirish (exotic shirish).
Portuguese: chorona.
Sanskrit: Shiriisha.
Sinhalese: mara.
Spanish: cenizaro, acacia preta, arbol de lluvia (rain tree), genizaro.
Sundanese: ki hujan (rain tree).
Tamil: thoongu moonji maram (sleepy tree).
Telugu: nidra ganneru.
Thai: dsha:m-dshu-ri:, jamjuree.
Vietnamese: cong, muong tim, cay mua (rain tree).