Gramineae

Gramineae family, Poaceae family, vegetative characters of Gramineae, Floral characters of Gramineae, Economic importance of gramineae/poaceae

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.

6. Floral Characters Inflorescence Spike or panicle or spikelet Axillary or terminal

7. Spikelet of Oryza

8. Flowers Bisexual In Zea mays – unisexual flowers In Spinifex – unisexual and dioecious Hypogynous (superior ovary) Zygomorphic and trimerous

9. Perianth Highly reduced and represented as lodicules Wedge-shaped lodicules Lodicules are hyaline or hygroscopic Bombusa – 3 lodicules Oryza sativa – 2 lodicules Ochlandra - numerous

10. 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

11. Gynoecium Monocarpellary, superior ovary, unilocular with one ovule. Styles - 1-3 Stigma is feathery

12. Pollination Anemophilous (wind pollination) Fruit Dry indehiscent – caryopsis Pericarp fused with seed coat bran

13. 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

14. 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

15. Intoxicating drinks are obtained on fermentation of certain grains Arrack - Rice Whisky - Rye and Barley Rum - Molasses of sugarcane Molasses

16. Saccharum officinarum - From the stem juice, sugar is obtained

17. Bambusa arundinacea – Bamboo. The stem is used for construction, making boats etc.

18. Cymbapogon citratus – Lemon grass oil is obtained from the leaves

19. Veteveria zizanoides – ( vetiver ) - An armotic oil is extracted from the roots. It is used in the perfumery

20. Spinifex squarrosus - Common on sea shore. Good sand binder.

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