1. Gramineae (poaceae)
R. NITHYA M. Sc., M. Phil., (Ph. D)
ASSISTANT PROFESSOR
DEPARTMENT OF BIOTECHNOLOGY
SRI ADI CHUNCHANAGIRI WOMENS COLLEGE, CUMBUM,
THENI DT, TAMILNADU
2. GRAMINEAE
Scientific Classification
Division - Spermatophyta
Sub-division - Angiosperms
Class - Monocotyledons
Sub-class - Polypetalae
Series - Glumaceae
Cohort - Ranales
Family - Gramineae or Poaceae
The family Gramineae is commonly called the Grass
family.
3. Distribution
Poaceae family contains 620 genera and 10,000
species.
It is the fourth largest family of Angiosperms.
Ranks first in economic importance
Distributed all parts of the world.
Common Plants
Triticum vulgare - Wheat
Zea mays - Corn
Oryza sativa - Rice
Saccharum officinarum - Sugarcane
Avena sativa - Oats
Bambusa arundinacea - Bamboo
Oats Barley
4. Vegetative Characters
Habit
Annual, or biennial or perennial herbs.
The stem is called culm.
It is hollow in the internodal portions and solid
at the nodal region.
In sugarcane , maize, etc., stem is solid throughout.
5. Leaves
Simple, alternate, distichous.
They are radical or cauline. Leaf base is sheathing.
Between leaf sheath and the blade, ligule is present.
Leaf blade is linear or lanceolate with parallel venation.
9. Flowers
Bisexual
In Zea mays – unisexual flowers
In Spinifex – unisexual and dioecious
Hypogynous (superior ovary)
Zygomorphic and trimerous
10. Perianth
Highly reduced and represented as lodicules
Wedge-shaped lodicules
Lodicules are hyaline or hygroscopic
Bombusa – 3 lodicules
Oryza sativa – 2 lodicules
Ochlandra - numerous
11. Androecium
3 stamens
Rarely 6 stamens - Oryza sativa
Bambusa
Numerous stamens - Ochlandra
one stamen - Uniola
Filaments - long , slender and hang out of flowers
Anther - Dithecous and versatile
14. Seed
Endospermous with a minute embryo
Endosperm occupies major portion of grain
Outermost layer of endosperm is aleurone layer
Embryo has single cotyledon – scutellum, plumule
and radicle
Plumule is covered by coleoptile
radicle - coleorhiza
15.
16. Economic Importance
Have great economic importance
The cereals which form the staple food of mankind, belong to
this family.
Vegetative parts serve as fodder for cattle
In the following members, the grains are used as food
Oryza sativa (paddy) - Rice
Triticum vulgare - Wheat
Hordeum vulgare - Barley
Zea mays - Maize
Pennisetum typhoides - Kambu
Eleusine coracana - Ragi
Setaria italica - Thinai
Andropogon sorghum - Cholam
Avena sativa - Oats
17. Intoxicating drinks are obtained on fermentation of certain grains
Arrack - Rice
Whisky - Rye and Barley
Rum - Molasses of sugarcane
Molasses