Millettia pinnata. Publication5.pub

Pongam (Millettia pinnata): Distribution, Identification and Uses
Stephen H. Brown, Lee County Horticulture Agent brownsh@ufl.edu
Kitty Tyler, Lee County Master Gardener
Mid-November
Racemes with flowers. Mid-May.
Family: Fabaceae
Common Names: Pongam, Pongamia
Synonyms (discarded names): Cytisus pinnatus,
Derris indica, Galedupa indica, G. pinnata,
Pongamia mitis, P. pinnata
Origin: From Indo-Malaysia to Australia
U.S.D.A. Zone: (9B-12B (25ºF minimum)
Plant Type: Medium to large tree
Growth Rate: Fast
Typical Dimension: 35’x55’
Shade Density: Heavy
Leaf Persistence: Briefly semi-deciduous
Flowering Season: Spring
Intense Blooming Days: 23
Flower Color: Pinkish, mauve or white
Light Requirements: Full sun to part shade
Soil Requirements: Wide
Drought Tolerance: High
Soil Salt Tolerance: Medium to high
Aerosol Salt Tolerance: High
Wind Tolerance: High
Nutritional Requirements: Medium
Propagation: Seeds
Motility: Self seeding
IFAS Assessment: Caution in South Florida;
not problematic in Central and North Florida
Human hazards: Toxic seeds
Major Potential Problems: Nutritional
deficiencies, Sri Lanka weevils
Uses: Shade tree, flowering tree, seaside tree,
street tree, screening, oily seeds used for
illumination and bio-fuel
Nativity and Distribution
Pongam (Millettia pinnata) has a wide naturally
occurring range from India east to Australia and
New Guinea. It is widespread in coastal areas,
tidal streams, mangrove forests and the flats of
humid rivers. It was introduced to the United
States in 1910 and grows well throughout Florida and Southern California. It is potentially a
weedy species wherever it is introduced.
Seed pods. Early January.
2
Growth Habit
This is an erect fast growing single trunk or multi-trunked tree usually from 32 to 40 feet tall. The trunk
is stout and the bark smooth and gray-brown. It is heavily foliated with dark green leaves, a rounded
symmetrical crown which flattens at the top with age, with somewhat drooping branches. The tree is
more or less deciduous, losing it leaves in late winter or early spring (February-March) and regrowth
beginning in April and May. Normally there is only one extended period of renewal growth each year.
The renewal shoots, especially those on saplings are long, arching little-branched with spirally-arranged
leaves. Two or more branches can arise at the same node, both of them flowering branches, or vegetative
and flowering branches intermixed.
Dense canopy and drooping branches. Mid-November.
Regrowth begins. Late April.
Seed pods are plentiful
on semi-deciduous tree.
Same tree. Early June.
3
Leaves
The compound leaves are alternate, usually 6 to 8 inches long. The leaf includes a 1.5 inch petiole that is
swollen at its base. They are odd-pinnate, with mostly 7, sometimes 5 or 9 ovate or broadly elliptic leaflets. Leaflets on the rachis are oppositely placed. Leaflets are entire, commonly 3 to 4 inches long and
1.5 to 2 inches wide. They are glossy and dark green above and pale green below. The canopy is pinkish
-red when new leaves are emerging. It becomes dark green when emergent is completed.
Dense foliage. Early November
Seven leaflets form an odd-pinnate leaf.
Flowers and Flowering
Flowers appear en masse from April to July, peaking in April and May. Flowering begins after the completion of renewal growth. There is an average of 23 intense blooming days. Flowers are produced on
racemes from either new terminal stem growth or from short new lateral flowering stems, both arising
from older growth. The racemes are up to 5 inches long and consist of loose clusters of flowers. The
flowers are small, 0.8 inches long including a 0.25 inch pedicel. They are faintly scented, pendent, and
papilionaceous (pea-like). Petals are pinkish, mauve or white and set in purplish brown calyxes. The
standard (the upper main petal) is erect and hooded. At its peak, there is a modest display of flowers as
many of the flowers are concealed by the tree’s dense foliage. Short-lived flowers are followed by
many woody seed pods.
Lateral
flowering stem
Terminal
flowering stem
Old growth
(gray wood)
Peak bloom. Late April.
Lateral and terminal flowering stems. Late April.
New growth flowering stems have green wood.
4
Racemes. Early May.
Flowers are approximately 0.8 inches long with a
hooded standard.
Fruit
The fruit is a flat, woody, broadly elliptic-oval, yellow to brown indehiscent pod. It is up to 2 inches
long and an inch wide, with incurving points, a stout stalk, and contains a single large seed. Fruit set is
abundant and many remain on the tree up to the time of leaf regrowth during the spring of the following
year.
Broad, woody pods.
Tree laden with seed pods. Early January.
Leaves, racemes, pods and seed.
5
Uses
Pongam is used as a medium-sized shade or flowering tree. The seeds and roots can be used to stun fish
which are then collected for food. The leaves and young growth are fed to cattle and other animals, especially in times of drought. Oil extracted from the seeds has been used as an ointment, as a lamp fuel, and
for the production of biodiesel.
Management
Pongam should be grown in full sun or partial shade in well-drained soil. It is a relatively low–
maintenance tree once established. It will show nutritional deficiencies if grown in soil with a pH above
7.5. The flowers and pods produce copious litter under the tree. This occurs several months apart. The
pods are stone-like and require cleanup after falling. Pods are poisonous, a fact which should be considered in placing the tree in the landscape, if any small children are present.
The tree has no major disease problems. Sri Lanka weevils and caterpillars make infrequent appearance
on the tree.
According to the UF/IFAS Assessment of the Statue of Non-Native Plants in Florida’s Natural Area,
Millittia pinnata may be used with caution in south Florida, but should be managed to prevent its escape.
It is not considered a problem species and may be used in central and northern growing zones of Florida.
Flower petals strewn on a sidewalk. Late April.
Pendent seed pods just before flowering. Late April.
6
New foliage just before bloom. Early May.
Tree in full bloom. Late May.
7
References
Bailey, L.H. 1937. The Standard Cyclopedia of Horticulture. The Macmillan Company, New York
Barwick, M. 2004. Tropical & Subtropical Trees: An Encyclopedia Timber Press, Inc. Portland, Oregon
Brown, S.H. 2014. South Florida Shade Trees: Identifications and Selections. UF/IFAS Lee County
Extension Service, Fort Myers, Florida
Gilman, E. and D.G. Watson. 2014. Pongamia pinnata: Pongam. ENH657. UF/IFAS
Extension, Gainesville, Florida
Nelson, G. 2010. The Trees of Florida. A Reference and Field Guide. Pineapple Press, Sarasota, Florida
Staples, G. and D.A. Herbst. 2005.Tropical Garden Flora: Plants cultivated in the Hawaiian Islands and
other Tropical Places. Bishop Museum Press, Honolulu, Hawai’i
Tomlinson, P.B. 1980. The Biology of Trees Native to Tropical Florida. Harvard Printing Office,
Allston, Massachusetts
Watkins, J. V. and T.J. Sheehan. 1975. Florida Landscape Plants. University of Florida Press,
Gainesville, Florida
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YouTube Landscape Channel
Stephen H. Brown’s Web Page
All pictures taken by Stephen H. Brown
This fact sheet was reviewed by Peggy Cruz, Lee County Extension. Pat Rooney, Lee County Master
Gardener.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, religion, age, disability,
sex, sexual orientation, martial status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension
Service, University of Florida, IFAS, Florida A. & M. 5/2015
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