This document defines inflorescence as the arrangement of flowers on a plant and describes the two main types: simple and compound. Simple inflorescences are further divided into racemose and cymose types. Racemose inflorescences have flowers arranged along a main stem with lower flowers developing first. Common racemose inflorescences include racemes, spikes, spikelets, catkins, spadices, corymbs, umbels, capitula, and hypanthodia. The document provides examples like sunflowers for capitula and banyan trees for hypanthodia.

1. Inflorescence
CHAPTER 7 ( BOTANY B)

2. Definition
the arrangement of
the flowers on a
plant.

3. Types of
inflorescence
• Simple
inflorescence
• Compound
inflorescence

4. Simple inflorescence
 Unbranched - They are also known as simple inflorescence
 It may be of two types
1. Racemose inflorescence
2. Cymose inflorescence

5. Racemose
In this type of inflorescence
the main axis does not end
in a flower, but it grows
continuously and develops
flowers on its lateral sides in
acropetal succession (i.e., the
lower or outer flowers are
older than the upper or inner
ones). The various forms of
racemose inflorescence may
be described under three
heads.

6. type
1. Raceme
2. Spike
3. Spikelets
4. Catkin
5. spadix.
6. Corymb
7. umbel.
8. capitulum or head.
9. Hypenthodium

7. Simple raceme
The main axis elongated, flowers
pedicellate, and the pedicel of all
flowers is same

8. Spike
In this type of racemose
inflorescence the main axis
remains elongated and the lower
flowers are older.
the flowers are sessile, i.e.,
without pedicel or stalk
e.g bottle brush

9. Corymb
Corymb is a racemose
inflorescence with a slightly
shortened axis. The older flowers
have the longer and the younger
flowers have the shorter
pedicels. As a result of this
flowers the carymb inflorescence
are found more or less at the
same level of arrangement.
e.g cadytufft

10. Catkin
This is a modified spike
with a long and
drooping axis bearing
unisexual flowers, e.g.,
mulberry (Moras alba)

11. Spadix
A thick fleshy spike, branched or
unbranched, enclosed with one
or more bracts
e.g maize , banana

12. Simple umbel
Umbel is also a type of racemose
inflorescence whose main axis is
shortened and at the tip bears a
whorl of bracts. All the flowers
are at the same level and they
show centripetal arrangement.
e.g Cherry

13. Capitulum
A head (capitulum) is a short dense
spike in which the flowers are borne
directly on a broad, flat peduncle,
giving the inflorescence the
appearance of a single flower
The inflorescence is surrounded by
one or more whorls of bracts called
involucre.
e.g
Sunflower (Helianthus annuus)

14. Ray florets
(marginal strap-
shaped flowers)
Ray florets are sterile, and disc
florets have both male and
female structures, including a
single ovary that develops into
a sunflower seed.

15. Disc florets (central
tubular flowers)
disc florets have both male and
female structures, including a
single ovary that develops into
a sunflower seed. A single
flower head may have up to two
thousand disc florets, each with
the potential to develop into a
seed.

16. Hypanthodium
in this type of inflorescence the
receptacle becomes spherical
with a cavity inside. It opens to
the outside with a small opening.
Numerous small sessile flowers
are produced from the inner
surface of the receptacle. These
flowers are of three types: male
flowers, female flowers and
sterile female flowers (gall
flowers) .
e.G banyan , fig, peepal

17. Banyan tree
inflorescence