Page 54 - Pharmacognosy-I (02-06-06-102)

receptacle. It is surrounded by involucre of bracts and there are
two types of florets in the same capitulum:

a. The central, tubular or disc florets which have tubular
corolla.

b. Ligulate or ray florets which have strap-like corolla.
3- Spike: having an elongated axis and sessile flowers (Plantago).
4- Strobile: A pike with large membranous scales concealing the

sessile flowers as in Humulus.
5- Umbel: with vary short axis, having obliterated internodes and

from which pedicels of nearly equal lengths are radiating thus
forming umbrella-like structure.
B- Cymose: definite inflorescence is characterized by the
sympodial branching which shows the oldest flower at the centre
and the youngest nearest the base or to the outside when seen
from above. The growth of the axis is limited by the formation
of a flower.
1- Simple cyme: The main axis terminates in a flower, one, 2 or
more stalked flowers arise on its pedicel originally in the axil
of bracteoles as in Tilia. It resembles umbel in appearance but it
differs in that the oldest flower being in the centre.
2- Compound cyme: The lateral branches continue to produce
further branches with flower.
a- Monochasium: or one-sided cyme, where the main axis
terminates in a flower which arises in the axil of a bract and its
pedicel bear two bracteoles one of which develops a lateral

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