InTrODUCTIOn

Rain tree (Samanea saman) is easily recognized by its char-

acteristic umbrella-shaped canopy. When grown in the

open, the tree usually reaches 15-25 m (50-80 ft) in height

with a canopy diameter wider than the tree is tall. Rain tree

is most important in the Pacific as a shade tree on small

farms, along roads, in parks and pastures. The wood has

limited use for carved bowls in local markets; it could be

developed more widely as a commercial timber, comparing

favorably to black walnut. A multitude of minor uses is

documented for rain tree, most of them of purely local sig-

nificance, but all could be explored for wider applicability.

Rain tree naturalizes freely almost everywhere it has been

introduced and is considered an invasive pest in Vanuatu

and Fiji. In many other places naturalized rain tree is not

considered a problem.

DISTrIbUTIOn

Native range

Extensive cultivation has obscured the native range of rain

tree. It is believed to be native in northern South America

(Colombia, the Caribbean slope and the Orinoco drainage

of Venezuela), and in Central America as far north as El

Salvador. It is now widespread from Mexico south to Peru,

Bolivia, and Brazil. In these areas, it occurs in low-eleva-

tion dry forests and grassland/savannah habitats.

Current distribution

Family

Fabaceae (alt. Mimosaceae), legume family

Subfamily

Mimosoideae

Non-preferred scientific names

Albizia saman (Jacquin) F. Mueller

Enterolobium saman (Jacquin) Prain ex King

Inga salutaris Kunth.

Inga saman (Jacquin) Willd

Mimosa saman Jacquin

Pithecellobium saman (Jacquin) Bentham

Common names

Pacific islands

filinganga (Northern Marianas)

gouannegoul, saman (French)

gumorni spanis (Yap)

kasia kula, mohemohe (Tonga)

marmar (New Guinea)

'ohai (Hawai'i)

rain tree, monkey pod, saman (English)

tamalini, tamaligi (Samoa)

trongkon-mames (Guam)

vaivai ni vavalangi, sirsa (Fiji)

Other regions

acacia, palo de China (Philippines)

algarrobo, algarrobo del país, carreto negro, delmont Samanea saman (rain tree)

Rain tree is cultivated and naturalized throughout the

tropics. In the Pacific, rain tree is known to occur on

the following islands: American Samoa (Tutuila), Com-

monwealth of the Northern Mariana Islands (Saipan,

Rota), Federated States of Micronesia (Chuuk, Kosrae,

Pohnpei), Fiji (Kanacea, Taveuni, Vanua Levu, Viti Levu),

French Polynesia (Íles Tubuai [Rurutu], Tahiti, Marquesas,

Moorea, Raiatea), Guam, Hawai'i, Marshall Islands (Jaluit,

Kwajalein), Niue, Palau (Koror), Papua New Guinea, the

Philippines, Pitcairn, Rotuma, Samoa ('Upolu), and Tonga

(Tongatapu, 'Eua, Vava'u, Lifuka/Foa). The species is also

naturalized in a number of the Caribbean Islands includ-

ing Puerto Rico. It is almost certainly even more wide-

spread than the foregoing list indicates.

bOTAnICAL DeSCrIPTIOn

Preferred scientific name

Samanea saman (Jacquin) Merrill

guannegoul, samán (Spanish)

gouannegoul, saman (French)

Size

Rain tree generally attains maximum heights of 15-25 m

(50-80 ft). In rare cases it can reach a height of 50 m (160

ft). The crown typically reaches 30 m (100 ft) in diameter.

Very large trees may reach 50-60 m (160-195 ft) in diam-

eter. Rain trees usually have a short, stout trunk of about

1-2 m (3-6.5 ft) in diameter at breast height (dbh), but the

trunk can attain 2-3 m (6.5-10 ft) dbh in exceptional cases.

Under dense planting conditions, trees may attain greater

height (to 40 m, 130 ft) with a narrower crown diameter

than when planted in the open.

Form

Rain tree has a distinctive, umbrella-shaped crown. The

crown is typically broad and domed; the horizontal spread

is greater than the height when grown in spacious, open

settings. Under plantation conditions, the crown is more

vase-shaped. Flowers

The tiny flowers (12-25 per head) are massed in pinkish

heads 5-6 cm (2-2.4 in) across and about 4 cm (1.6 in) in

rAIn Tree?

The name rain tree has been attributed to:

• The leaflets are light-sensitive and close together on

cloudy days (as well as from dusk to dawn), allowing

rain to fall through the canopy to the ground below.

• The grass is often much greener under a rain tree

than the surrounding grass.

• A steady drizzle of honeydew is often created by

sap-sucking insects.

• Nectaries on the leaf petioles excrete sugary juice

that sometimes falls from the tree like rain.

• During heavy flowering, stamens can drop from the

canopy like rain.

height. The long, bicolored stamens (white in lower half

and reddish above) give the whole inflorescence the ap-

pearance of a powder puff or feather duster held slightly

above the foliage. Thousands of heads are borne at the same

time, covering the tree in pinkish bloom. The central flower

in each head is larger, stalkless, has more petals, and is in-

capable of forming a fruit; this flower is a nectar-produc-

ing organ that attracts pollinators. Usually only one flower

per head (rarely two) is pollinated and forms a fruit.

Leaves

Leaves are alternately arranged along twigs and have a

prominent swelling (pulvinus) at the petiole base; stipules

are present and threadlike; the leaf blades are twice-even-

pinnately compound, arranged in 2-6 pairs of pinnae, each

pinna bearing 6-16 diamond-shaped leaflets, shiny green

above, dull and finely hairy beneath, 2-4 cm (0.8-1.6 in)

long and 1-2 cm (0.4-0.8 in) wide, the apical leaflets larg-

est. During dry periods trees are semi-deciduous, losing

their leaves for a short period. Where there is a definite dry

season, they may remain leafless for a period of weeks but

refoliate quickly if there is adequate moisture. This gives

the appearance that rain tree is "evergreen" in moister cli-

mates.

Fruit

Mature pods are black-brown, oblong, lumpy, 10-20 cm

long (4-8 in), 15-19 mm (0.6-0.8 in) wide, ca. 6 mm (0.25

in) thick, straight or slightly curved, not dehiscing but

eventually cracking irregularly, and filled with a sticky,

brownish pulp that is sweet and edible.

Top: Flowers and new leaves. Bottom: Fruit in varying stag-

es of ripeness. photos: C. ElEvitCh InTrODUCTIOn

Rain tree (Samanea saman) is easily recognized by its char-

acteristic umbrella-shaped canopy. When grown in the

open, the tree usually reaches 15-25 m (50-80 ft) in height

with a canopy diameter wider than the tree is tall. Rain tree

is most important in the Pacific as a shade tree on small

farms, along roads, in parks and pastures. The wood has

limited use for carved bowls in local markets; it could be

developed more widely as a commercial timber, comparing

favorably to black walnut. A multitude of minor uses is

documented for rain tree, most of them of purely local sig-

nificance, but all could be explored for wider applicability.

Rain tree naturalizes freely almost everywhere it has been

introduced and is considered an invasive pest in Vanuatu

and Fiji. In many other places naturalized rain tree is not

considered a problem.

DISTrIbUTIOn

Native range

Extensive cultivation has obscured the native range of rain

tree. It is believed to be native in northern South America

(Colombia, the Caribbean slope and the Orinoco drainage

of Venezuela), and in Central America as far north as El

Salvador. It is now widespread from Mexico south to Peru,

Bolivia, and Brazil. In these areas, it occurs in low-eleva-

tion dry forests and grassland/savannah habitats.

Current distribution

Family

Fabaceae (alt. Mimosaceae), legume family

Subfamily

Mimosoideae

Non-preferred scientific names

Albizia saman (Jacquin) F. Mueller

Enterolobium saman (Jacquin) Prain ex King

Inga salutaris Kunth.

Inga saman (Jacquin) Willd

Mimosa saman Jacquin

Pithecellobium saman (Jacquin) Bentham

Common names

Pacific islands

filinganga (Northern Marianas)

gouannegoul, saman (French)

gumorni spanis (Yap)

kasia kula, mohemohe (Tonga)

marmar (New Guinea)

'ohai (Hawai'i)

rain tree, monkey pod, saman (English)

tamalini, tamaligi (Samoa)

trongkon-mames (Guam)

vaivai ni vavalangi, sirsa (Fiji)

Other regions

acacia, palo de China (Philippines)

algarrobo, algarrobo del país, carreto negro, delmont Samanea saman (rain tree)

Rain tree is cultivated and naturalized throughout the

tropics. In the Pacific, rain tree is known to occur on

the following islands: American Samoa (Tutuila), Com-

monwealth of the Northern Mariana Islands (Saipan,

Rota), Federated States of Micronesia (Chuuk, Kosrae,

Pohnpei), Fiji (Kanacea, Taveuni, Vanua Levu, Viti Levu),

French Polynesia (Íles Tubuai [Rurutu], Tahiti, Marquesas,

Moorea, Raiatea), Guam, Hawai'i, Marshall Islands (Jaluit,

Kwajalein), Niue, Palau (Koror), Papua New Guinea, the

Philippines, Pitcairn, Rotuma, Samoa ('Upolu), and Tonga

(Tongatapu, 'Eua, Vava'u, Lifuka/Foa). The species is also

naturalized in a number of the Caribbean Islands includ-

ing Puerto Rico. It is almost certainly even more wide-

spread than the foregoing list indicates.

bOTAnICAL DeSCrIPTIOn

Preferred scientific name

Samanea saman (Jacquin) Merrill

guannegoul, samán (Spanish)

gouannegoul, saman (French)

Size

Rain tree generally attains maximum heights of 15-25 m

(50-80 ft). In rare cases it can reach a height of 50 m (160

ft). The crown typically reaches 30 m (100 ft) in diameter.

Very large trees may reach 50-60 m (160-195 ft) in diam-

eter. Rain trees usually have a short, stout trunk of about

1-2 m (3-6.5 ft) in diameter at breast height (dbh), but the

trunk can attain 2-3 m (6.5-10 ft) dbh in exceptional cases.

Under dense planting conditions, trees may attain greater

height (to 40 m, 130 ft) with a narrower crown diameter

than when planted in the open.

Form

Rain tree has a distinctive, umbrella-shaped crown. The

crown is typically broad and domed; the horizontal spread

is greater than the height when grown in spacious, open

settings. Under plantation conditions, the crown is more

vase-shaped. Flowers

The tiny flowers (12-25 per head) are massed in pinkish

heads 5-6 cm (2-2.4 in) across and about 4 cm (1.6 in) in

rAIn Tree?

The name rain tree has been attributed to:

• The leaflets are light-sensitive and close together on

cloudy days (as well as from dusk to dawn), allowing

rain to fall through the canopy to the ground below.

• The grass is often much greener under a rain tree

than the surrounding grass.

• A steady drizzle of honeydew is often created by

sap-sucking insects.

• Nectaries on the leaf petioles excrete sugary juice

that sometimes falls from the tree like rain.

• During heavy flowering, stamens can drop from the

canopy like rain.

height. The long, bicolored stamens (white in lower half

and reddish above) give the whole inflorescence the ap-

pearance of a powder puff or feather duster held slightly

above the foliage. Thousands of heads are borne at the same

time, covering the tree in pinkish bloom. The central flower

in each head is larger, stalkless, has more petals, and is in-

capable of forming a fruit; this flower is a nectar-produc-

ing organ that attracts pollinators. Usually only one flower

per head (rarely two) is pollinated and forms a fruit.

Leaves

Leaves are alternately arranged along twigs and have a

prominent swelling (pulvinus) at the petiole base; stipules

are present and threadlike; the leaf blades are twice-even-

pinnately compound, arranged in 2-6 pairs of pinnae, each

pinna bearing 6-16 diamond-shaped leaflets, shiny green

above, dull and finely hairy beneath, 2-4 cm (0.8-1.6 in)

long and 1-2 cm (0.4-0.8 in) wide, the apical leaflets larg-

est. During dry periods trees are semi-deciduous, losing

their leaves for a short period. Where there is a definite dry

season, they may remain leafless for a period of weeks but

refoliate quickly if there is adequate moisture. This gives

the appearance that rain tree is "evergreen" in moister cli-

mates.

Fruit

Mature pods are black-brown, oblong, lumpy, 10-20 cm

long (4-8 in), 15-19 mm (0.6-0.8 in) wide, ca. 6 mm (0.25

in) thick, straight or slightly curved, not dehiscing but

eventually cracking irregularly, and filled with a sticky,

brownish pulp that is sweet and edible.

Top: Flowers and new leaves. Bottom: Fruit in varying stag-

es of ripeness. photos: C. ElEvitCh

Resources

Top Categories

Product

Company