BOTANY Higher Secondary Second Year - Textbooks Online

(eg. Jatropha curcas). In xerophytic species of Euphorbia, leaves are
reduced or absent. The leaves around the cyathium become beautifully
coloured in E. pulcherrima (Paalperukki tree).
Inflorescence
The characteristic inflorescence of Euphorbia is cyathium. It is a
collection of unisexual flowers arranged in cymose manner on a condensed
axis and enclosed within a cup-shaped involucre. Each cyathium has a
single central female flower surrounded by two to many male flowers.
Each male flower is represented by a single stamen. They are arranged in
centrifugal manner. The pedicel in female flower is short or long. If it is
short, the female flower remains hidden within the involucre. If it is long,
the female flower comes out of involucre. Extra floral nectar secreting
gland is also located in the cyathium.
Various types of inflorescence are seen in the members of
Euphorbiaceae. In Ricinus communis, it is a panicle where female and
male flowers are arranged in racemose manner. Female flowers are at the
top and male flowers below. In Croton sparsiflorus (Eli amanakku), the
inflorescence is simple raceme, whereas in Acalypha indica (Kuppaimeni),
it is catkin. In Phyllanthus amarus, the male and female flowers are
axillary and solitary.
Flower
Bracteate, ebracteolate, pedicellate, unisexual, monoecious or dioecious,
incomplete and hypogynous. In Euphorbia , the male flower is represented
by a single stamen and female flower by a single pistil.
Perianth
In Croton sparsiflorus, the male flowers have two whorls of perianth
whereas the female flowers have a single whorl of perianth. The male
and female flowers of Euphorbia are usually devoid of perianth i.e aphyllous.
The tepals are polyphyllous in Phyllanthus amarus and gamophyllous in
Ricinus communis.
Androecium
Stamen one to many, free or united. In Ricinus communis, the stamen
is polyadelphous and the filaments are branched. They are fused into
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