5. Spadix
is the characteristic inflorescence of the remarkable arum family
(Araceae).
It consists of a thickened, fleshy axis (spike) bearing clusters of
sessile, apetalous, unisexual flowers.
The small unisexual flowers are packed together along the lower
region of an erect, phallus-like central spike, typically with male
flowers above the female.
The upper region of the spadix is usually devoid of flowers.
Male (staminate) flowers consist of numerous stamens packed
together.
6. while female (pistillate) flowers consist of numerous
individual pistils.
Individual flowers are reduced to a single stamen or pistil
(gynoecium).
The spadix emerges from a vase-shaped or funnel-like
modified leaf or spathe which is often brightly colored.
The spadix of some arums emits a putrid odor that
attracts carrion flies for pollination.
11. Umbel
- The peduncle of this type of inflorescence bears
all of the pedicels at its apex.
Hydrangea (Hydrangea
macrophylla) Lantana (Lantana sp)
12. Compound
Umbel
- The peduncle
bears a number of
primary pedicels at
its apex. These do
not bear flowers but
a number of
secondary pedicels
at their apices
which in turn bear
the flowers. Frangipani (Plumeria rubra)
13.
14. Spike
- This
inflorescence
type has a long,
unbranched
main axis which
bears flowers
which have no
pedicels or very
short pedicels. Silver oak (Grevillea robusta)
16. Head (capitulum)
- which do not have pedicels
- are grouped together on the top of a peduncle
which may be flattened or rounded.
- Daisies (Asteraceae) are a good example
- outer flowers may have one very large petal
- In other families the whole inflorescence may
be surrounded by bracts e.g. the Proteas.
- This gives the impression that the whole
structure is a single flower but it may infact be
hundreds of flowers grouped together.
19. A Corymb
- The main axis of this
inflorescence type is
elongated and
unbranched as in a
raceme, but the pedicels
of the flowers are of
unequal length so that
the entire structure
appears flat-topped.
Examples include
hawthorn, the apple and
dogwood. Crataegus calpodendron