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Family : Gramineae (grass family )

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  • by Suz over 1 year ago

It is commonly known as grass family.

CLASSIFICATION

kingdom: plantae

division : phanerograms

Class: Monocotyledonae

Series: Glumaceae

Order: Graminales

Family: Gramineae

New name: Poaceae


Distribution
This is the largest family of monocotyledon which includes 668 genera and more than 10,000 species. The members are cosmopolitan in distribution. Many cereal plants are included in this family. Thus, this family is considered as the economically important family.

Root
The adventitious root system, some grasses shows moniliform roots whereas in Zea mays stilt roots are present.
Stem
Aerial, erect or prostrate, simple, sometimes branched near the base, solid and swollen node, fistular internode, cylindrical, glabrous, sometimes glaucous.


Leaf
Cauline and ramal, ex-stipulate, sessile, simple, alternate, ligulate, leaf consists of leaf sheath and leaf blade with auricles and ligule. Leaf sheath partially or completely covers the internode. At the junction of leaf sheath and leaf blade, thin membranous ligule is present. A pair of pointed claw like appendages known as auricles occur on either side of ligule, leaf blade is thin, flattened, narrow, linear to lanceolate with parallel venation.

Inflorescence
Spike or panicle of spikelet. The inflorescence consists of many spikelets attached to the main axis known as rachis. Each spikelet consists of one to many florets attached to the central axis known as rachilla. A pair of sterile glumes occours at the base of spikelets

Floret
Bracteate, bracts are represented by outer lemma and inner pulea, sessile complete, rarely incomplete, bisexual, rarely unisexual(Zea mays), zygomorphic, trimerous hypogynous.
Perianth
Sepals modified into 2 or 3 lodicules, sometimes absent(Bambusa).

Androecium
Stamens 3 polyandrous, sometimes 6 (Oryzae, Bambusa), 2 (Sporobolus), 1(Uniola), anthers dithecous, versatile, sometimes dorsifixed, extrorse, inferior.
Gynoecium
Carpel 1, monocarpellary, sometimes 2 or 3 bi or tri carpellary, syncarpous, ovary superior, unilocular with single ovule in basal placentation, style 2, sometimes 3 (Bambusa) or 1(Nardus), stigma two lateral feathery.
Fruit Caryopsis

Economic importance
Oryzae Sativa (Rice)
Triticum aestivum (Wheat)
Zea mays (Maize)
Hordeum vulgare (Barley)
Cynodon dactylon (Grass)
Saccharum officinarum (Sugarcane)