The plants of this family are found throughout the world. However, they are not found in arctic regions. In our country the family is represented by several genera such as, Euphorbia, Ricinus, Phyllanthus, Croton, Pedilanthus, etc. In the desert regions of Africa and elsewhere the family is represented by cactus-like plants of different species of Euphorbia.
Heath like Euphorbias are quite common in Australia. In Britain only two genera, i.e., Euphorbia and Mercurialis are found, which are represented by sixteen and two species respectively.
9. Pedicellate
ď‚› A flower which bears a stalk or
pedicel is called as a pedicellate
flower e.g. Hibiscus, Rose.
A flower which is borne
directly on the stem is called
to be a sessile flower. It is
devoid of a stalk.
Sessile flower
11. Perianth
• Tepals 5 (that is not clearly differentiated into petals and sepals)
• Arranged in single whorl (flower is cyclic)
• Gamophyllous (jointed whorl)
• Valvate Aestivation
(perianth is the sterile parts of a flower)
12. Aestivation
ď‚› Floral leaves in a whorl may just touch one
another at the margins without overlapping
Aestivation is the positional arrangement of the parts
of a flower within a flower.
Valvate Aestivation
13. Androecium
• Stamens - 5
• Polyadelphous - When the filaments of the stamens are
united to form several bundles
• Dithecous Anther - Two lobes which are attached at the
back by connective
• Basifixed - an anther is attached from its base to the
filament
• Introrse - Anther dehiscence takes place toward
the centre of the flower.
14. Polyadelphous
ď‚› The androecium of a flower can show varying degree
of fusion between filaments and anthers. When the
filaments of the stamens are united to form several
bundles, the condition is called polyadelphous. It is
seen in lemon.
20. Pedicellate
ď‚› A flower which bears a stalk or
pedicel is called as a pedicellate
flower e.g. Hibiscus, Rose.
A flower which is borne
directly on the stem is called
to be a sessile flower. It is
devoid of a stalk.
Sessile flower
22. Perianth
• Calyx -3 to few or more
• Caducous - falling of calyx before usual time
• Spathaceous
• Valvate Aestivation.
(perianth is the sterile parts of a flower)
24. Aestivation
ď‚› Floral leaves in a whorl may just touch one
another at the margins without overlapping
Aestivation is the positional arrangement of the parts
of a flower within a flower.
Valvate Aestivation
25. Gynoecium
• 3 carpels (tricarpellary)
• Syncarpous (capels united)
• Ovary superior
• Trilocular with spiny outgrowths,
• Axile placentation
• single large ovule in each locule
• three styles, three bifid stigmas.
26. Ovary superior
An ovary attached to the
receptacle above the attachment
of other floralparts.
Trilocular
In this type, an ovary consists
of a single chamber
27. Axile Placentation
ovules are borne at or around
the center of a compound ovary
on an axis formed from joined
septa.
28. POLLINATION
• Entomophilous, i.e., through the agency
of insects. In many species the leaves and
bractsbecome coloured and showy to
attract the insects
• Cross- pollination takes place
• Anemophily is also found. through
wind.