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Friday 9 January 2009

FAMILY OF THE WEEK: SAPINDACEAE


Schleichera oleosa (Kusam)


Sapindus


Sapindus

FAMILY OF THE WEEK: SAPINDACEAE ACERACEAE(MAPLE FAMILY)
Large family represented in India by 24 genera and 72 species occurring in the tropical eastern Himalayas and western peninsular India.
Vegetative characters:
The members of the family are trees or shrubs or sometimes vines. The stems show peculiar secondary growth in thickness.
The leaves are alternate or rarely opposite (Acer), usually pinnately compound, sometimes simple (Cardiospermum), palmately lobed and veined (Acer) or digitate (Aesculus). They are exstipulate but occasionally stipulate as in Melianthus. The latex or resin cells are often present in the leaves.
Inflorescence and flowers:
Racemose inflorescence with minute flowers or unilateral cymes in panicles. The flowers are mostly polygamo-dioecious. They are zygomorphic or occasionally actinomorphic, tetra or pentamerous and hypogynous.
The calyx is composed of four or five sepals which are free or variously connate, often unequal and valvate or imbricate in bud.
The corolla is of four to five free petals but usually there are four petals and the place of fifth petal is vacant.
The androecium has typically eight or ten stamens or sometimes less as in Aesculus.
An annular or unilateral disc is often present between the petals and the stamens.
The gynoecium is usually tricarpellary and syncarpous. The ovary is superior.
Fruits and the seeds:
The fruit is capsular or it is indehiscent and entire or lobed as in Sapindus. Sometimes the fruit is a double Samara as in Acer or nutlike as in Litchi.
The seeds are globose or compound, often arillate, endospermic or nonendospermic with often plicate or spirally convolute embryo.
Pollination and dispersal:
The flowers are often protandrous and pollinated by insects. Flies and humble bees are the chief pollinators.The fruits of Dodonia and Acer are blown to long distances by strong winds. The dispersal also takes place by birds and animals in many genera.
Examples:
Litchi chinensis
Sapindus mukorossi (Soapnut tree, Ritha)
Sapindus laurifolius Acer saccharinum (Sugar Maple)
Aesculus hippocastanum (Horse chestnut)
Schleichera oleosa (Kusam)
Dodonia viscose (Vilayati Mehandi)
Nephelium lappaceum (Rambutan)

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