Page 45 - Pharmacognosy-I (02-06-06-102)

2- Gamopetalous: the petals are united by the margin.
Insertion of corolla:

According to the attachment of the petals to the receptacle in
relation to the position of the ovary, the corolla may be:

a) Hypogynous: the corolla is inserted on the receptacle below
the ovary e.g. stramonium.

b) Perigynous: the corolla is inserted on the edge of hollow
receptacle which surrounds the ovary but does not fuse with it
e.g. Rose.

c) Epigynous: the corolla is inserted on the receptacle which has
fused with and closed over the ovary e.g. cloves.

Form of Corolla:
The corolla is described as regular when the petals are alike

or irregular when the petals differ in shape and size. When
sympetalous the corolla is described as:
a- Tubular: when united in tube-like structure e.g. disc florets of

Asteraceae.
b- Ligulate: i.e. strap-shaped with short tubular base e.g. ray

florets of
Asteraceae.
c- Bilabiate: i.e. bilipped (e.g. family labiatae) and with open
throat.

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