BOTANY Higher Secondary Second Year - Textbooks Online

Inflorescence
Usually a raceme eg. Crotalaria verrucosa (Kilukiluppai) or a panicle
(eg. Dalbergia latifolia) or axillary solitary (eg. Clitoria ternatea).
Flower
Bracteate, pedicellate, bracteolate, complete, bisexual, pentamerous,
dichlamydeous, zygomorphic and hypogynous.
Calyx
Sepals 5, green, gamosepalous showing valvate aestivation. Odd
sepal is anterior in position.
Corolla
Petals 5, coloured, polypetalous showing descendingly imbricate or
vexillary aestivation. The outer most petal is large called standard petal
or vexillum. Two lateral petals are lanceolate and curved. They are
called wing petals or alae. Two anterior and partly fused innermost petals
are called keel petals or carina. The stamens and pistil are enclosed by
these keel petals. All the petals have a claw at their bases. This type of
irregular corolla is described as papilionaceous corolla.
Androecium
Stamens 10, usually diadelphous. Nine stamens are fused to form a
bundle and the tenth stamen is free (9) + 1 (eg. Clitoria ternatea). The
odd stamen is posterior in position. In Aeschynomene aspera, the stamens
are fused to form two bundles each containing five stamens (5) + (5). In
Crotalaria verrucosa the stamens are monadelphous and dimorphic i.e. 5
stamens have longer filaments and other 5 stamens have shorter filaments.
Thus the stamens are found at two different levels and the shape of anthers
also varies. 5 anthers are long and lanceolate. The other 5 anthers are
short and blunt. Anthers are dithecous, basifixed and dehiscing
longitudinally.
Gynoecium
Ovary superior, monocarpellary, stipitate i.e. ovary has a short stalk
at the base. Ovary unilocular with one to many ovules showing marginal
placentation. Style simple and bent. Stigma flattened or feathery.
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