This document describes various types of inflorescences including racemose, cymose, mixed, and special types. Racemose inflorescences include racemes, panicles, spikes, compound spikes, catkins, corymbs, and umbels. Cymose inflorescences include solitary cymes, simple cymes, monochasial cymes, dichasial cymes, and polychasial cymes. Mixed inflorescences include thyrsus and fascicles. Special inflorescences include verticillasters, hypanthodium, and cyathium. Each type is defined and an example is provided.

1. R. NITHYA M. Sc., M. Phil., (Ph. D)
ASSISTANT PROFESSOR IN BIOTECHNOLOGY
SRI ADI CHUNCAHNAGIRI WOMEN’S COLLEGE, CUMBUM,
THENI DT, TAMIL NADU.

2. INFLORESCENCE
Cluster of flowers attached to peduncle is an inflorescence.
Peduncle - The stalk of inflorescence
Pedicel - the stalk of individual flowers
Sessile - Flower without stalk
Bract - the leafy structures in the axil of flowers
Involucre - cluster of bracts in a whorl
Bracteoles - structures lying between flower and bract.
Peduncle of the inflorescence is branched or unbranched.

3. TYPES OF INFLORESCENCE
Four types
Racemose
Cymose
Mixed
Special

4. RACEMOSE OR INDEFINITE INFLORESCENCE
Peduncle grows continuously.
It does not terminate in a flower.
Flowers are produced in acropetal order - Younger flowers are at tip
Older flowers are at the base

5. TYPES OF RACEMOSE INFLORESCENCE
Raceme
Panicle
Spike
Compound spike
Catkin or Ament
Corymb
Umbel
Spadix
Compoundsapdix
Head or Capitulum
Spike-let of Grass

6. RACEME INFLORESCENCE
- Unbranched, one pedicellate.
- Acropetal succession
- Simplest type
E.g. Crotalaria

7. PANICLE
- Compound raceme
- Peduncle is branched
- Flowers – Acropetal succession
- E.g. Yucca, Mangifera

8. PANICLE - Mangifera

9. SPIKE
Flowers – Sessile
Acropetal succession on the
main axis
Spike is a modified raceme.
E.g. Achyranthes

10. COMPOUND SPIKE
The main axis is branched
with sessile flowers.
E.g. Amaranthus spinosus

11. CATKIN OR AMENT
The peduncle of inflorescence is pendent
Bears unisexual flowers
Arranged in acropetal order
E.g. Acalypha

12. CORYMB
Main axis of the inflorescence is short
Bears pedicellate flower
Acropetal succession
Pedicel of older flowers are long
Younger flower is short. E.g. Cassia.

13. UMBEL
Main axis become very shortened.
All stalked flowers arise
at common point.
Two types –simple and compound
SIMPLE UMBEL
Main axis ends in whorl
of bracts
Flower produced in the axil of each bract.
Pedicel of flowers are more or less equal in length.
E.g. Allium

14. COMPOUND UMBEL
The main axis of the inflorescence
ends in whorl of involucel
of bracts.
In the axil of each bract
secondary peduncle is formed.
It also ends in involucel of bracts.
Pedicellate flowers are produced in
the axil of the involucel of bracts
E.g. Coriandrum.

15. SPADIX
Peduncle is fleshy and the
Sessile flowers are sunk in the
Peduncle.
The peduncle is enclosed by
a large bract known as spathe.
E.g. Colocasia

16. COMPOUND SPADIX
- The main axis is branched
- In Cocos nucifera, inflorescence
is enclosed by woody bract.
- Flowers are sessile, unisexual
and arranged on secondary
peduncles
- Female flowers are few arranged at base
- Male flowers are numerous found
in the upper part of secondary peduncle.

17. HEAD OR CAPITULUM
The peduncle ends in a platform
like structure called receptacle.
The receptacle bears
numerous, small sessile flowers.
The small reduced flowers – florets.
The receptacle bears involucre of bracts
at the periphery.
E.g. Sunflower

18. Sunflower
The head is heterogenous
Consists two types of florets
Disc florets
Ray florets
The florets at the centre are
called disc florets
The florets at the periphery –
ray florets.

19. SPIKE-LET OF GRASS
It is a compound spike
Each spikelet has
Central axis – Rachilla
Rachilla bears few bracts – glumes
The lower glumes sterile – Lemma
Sterile glumes – empty glumes.
The upper fertile glumes – palea.
The perianth is reduced – Lodicules.
Above the lodicules androecium and
gynoecium present.

20. CYMOSE INFLORESCENCE
In cymose the peduncle grows
and terminates in a flower.
Further flowers are produced
laterally.
Flowers - basipetal arrangement
The central flower is older.
The lateral flowers are younger.

21. SOLITARY CYME
The peduncle grows and terminate in a single flower
The lateral flowers do not present
E.g. Hibiscus

22. SIMPLE CYME
It is a cluster of three flowers.
Main axis or peduncle ends in
a flower(central and older).
Two lateral flowers are younger
E.g. Jasmine

23. MONOCHASIAL CYME
The main axis ends in a flower
It bears one lateral branch
below the terminal flower
in the axil of a bract.
Two types
Monochasial helicoid cyme
Monochasial scorpiod cyme

24. MONOCHASIAL HELICOID CYME
Main axis terminates in
a flower and lateral
Flowers are produced
on the same side.
So the flowering branch becomes
curved on the side.
E.g. Hamelia.
This helicoid type of branching
is called Dreparium.

25. MONOCHASIAL SCORPIOD CYME
Main axis ends in a flower and lateral flowers are formed alternately on one
side only, So the flowering branch becomes zig-zag in growth.
E.g. Heliotropium
The scorpioid cyme is called cincinnus.

26. DICHASIAL CYME OR BIPAROUS CYME
The main axis ends in a flower, which
has two opposite bracteoles.
Flower arise from each bracteole
Each of these flowers again has two
bracteoles from this third set of flowers arise.
The cluster of flowers can be broken up into small
groups of three flowers each.
E.g. Clerodendron

27. POLYCHASIAL CYME OR MULTIPAROUS CYME
The main axis ends in a flower and
two or more flowering branches
are formed laterally below the
terminal flower.
E.g. Croton

28. MIXED INFLORESCENCE
Mixed inflorescence are
partly racemose and
partly cymose
THYRSUS
The main flowering branch
is racemose
The ultimate branches are cymose.
This is a type of panicle
E.g. Ocimum

29. FASICLE
It is a clustered form
of inflorescence and
the flowers are short
and crowded.
E.g. Polyalthia

30. SPECIAL TYPES OF INFLORESCENCE
VERTICILLASTER
-Condensed cymose inflorescence
- Develops in the axil of pair of opposite leaves.
- First order of branching is dichasial
further branching are monochasial. E. g. Leucas

31. HYPANTHODIUM
It is also called syconium, condensed
form of cymose inflorescence
The inflorescence axis is enlarged
Into flask shaped receptacle with a
central cavity.
Receptacle opens at the top by osltiole
guarded by incurved hairs.
Numerous small sessile flowers arranged
Along the inner wall of receptacle.
E.g. Ficus
Male flowers are placed towards the top of the cavity
Female towards the bottom.

32. CYATHIUM
- It is condensed inflorescence looks like a flower.
- It consists cup like structure
formed of involucre of bracts.
- Female flower –present at the centre of cup,
single, stalked with tri-carpellary ovary.
It seen outside the cup.
-Male flowers-reduced, five scorpoid cyme
surrounds the central female flower.
-Single stamen represents the male flower.
E.g. Euphorbia hetrophylla