The document discusses types of inflorescence, which refers to the arrangement of flowers on a plant's floral axis. It distinguishes between racemose and cymose types, detailing various forms such as raceme, corymb, umbel, spike, and capitulum, among others. Additionally, it highlights the importance of this topic in scoring well on exams, noting that it typically features 2-3 straightforward questions per year.

1. Unit – II : Inflorescence – Cymose and Racemose
Presented by Debanjan pandit, faculty of Raidighi college

2. Why This Portion is Important ??
 Comparatively easy to score area.
 This portion contains 2-3 Questions per year.
 Straight forward questions.
 Tricks to remember all things.
Inflorescence means the arrangement of the flower or flowers on the floral axis of a plant.

4. Racemose Type :The main axis grows indefinitely
giving rise to younger flowers in an acropetal and
centripetal order.
(oldest flower towards base, and younger flower
towards apex)
Cymose Type: The apical bud is a flower. The
younger flowers are borne below it, in a basipetal and
centrifugal manner.
(oldest flower towards apex, and younger flower
towards base)
Types of Inflorescence

6. Raceme :
The main axis
has indefinite
growth ,
where more or
less equally
pedicellate
flowers are
bourne, e,g.,
Brassica
nigra
(Brassicaceae)

7. Corymb:
Raceme, in which
all the flowers
reach the same
level due to more
elongation of the
pedicel of older
flowers, e.g.,
cherry Prunus
cerasus

8. Umbel:
When pedicellate
flowers arise from a
common point as in
members of
Umbelliferae or
Apiaceae.
(Coriandrum
sativum)

9. Spike:
A raceme with sessile
flowers, e.g.,
Adhatoda vasica,
Callistemon, etc.

10. Spikelet:
Small spikes arranged in a
spike, raceme or panicle
manner. Each flower consists
of an awned bract, three
stamens and an ovary with
two feathery stigmas, e.g.,
Triticum aestivum.

11. Spadix:
Spike with a fleshy axis, enclosed
by one or more large bracts called
spathes, e.g., Colocasia ,Musa,
Pistia , etc

12. Catkin:
Pendant spike with unisexual flowers, e.g., Acalyphya
hispida, Morus alba, Salix

13. Strobile :
Modified spike
where the pistillate
flowers are borne
singly in the axile
of persistent
membranous bract
e.g., Humulus
lupulus

14. Capitulum or Head:
When numerous, small,
sessile flowers are
aggregated to form a dense
inflorescence as in members
of Compositae or
Asteraceae. E.g., Helianthus
annuus

15. Capitate : A dense cluster of
sessile flowers arise upon a
compressed rachis. e,g., Mimosa
pudica

16. Compound Raceme or Panicle:
In this case the raceme is branched, and the branches bear flowers in a
racemose manner, e.g., Delonix regia, Azadirachta indica, Clematis
buchaniana, Cassia fistula, etc.

17. Compound Corymb:
Also known as corymb of corymbs. Here the main axis (peduncle) branches in a
corymbose manner and each branch bears flowers arranged in corymbs. Typical
example-cauliflower(Brassica oleracea var. botrytis).

18. Compound Umbel:
Also known as umbel of umbels. Here the peduncle (main axis) is short and bears many
branches which arise in an umbellate cluster. Each such branch bears a group of flowers in an
umbellate manner. Usually a whorl of leafy bracts is found at the base of branches and also at
the bases of flowers arranged in umbellate way. The former whorl of bracts is called involucre
and the latter involucel. Typical examples of compound umbel are—Daucus carota (carrot),
Foeniculum vulgare (fennel), Coriandrum sativum (coriander),

19. Compound Spike:
Also known as spike of spikelets.Branches of the main axis bear
spike inflorescence. e.g., Amaranthus viridis, Amaranthus spinosus

20. Amaranthus spinosus

21. Compound Spadix:
Also known as spadix of spadices. Here the main axis (peduncle) remains branched in a
racemose manner and each branch bears sessile and unisexual flowers. The whole
branched structure remains covered by a single spathe. The examples are common in
Palmaceae (Palmae) family. cocos nucifera

22. Compound Head:
Also known as head of
heads or capitulum of
capitula. In this case
many small heads form
a large head. The typical
example is globe thistle
(Echinops). In this plant
the heads are small and
one-flowered and are
arranged together
forming a big compound
head.