poaceae
poaceae is one of the most important plant families , it contains a lot of economic plant .
most of the grain crops are members of this family such as corn , wheat , rice and Barley
most of the grain crops are members of this family such as corn , wheat , rice and Barley
morphology of family poaceae
Grasses generally have the following characteristics
Poaceae have hollow stems called culms plugged at intervals by solid leaf-bearing nodes. Grass leaves are nearly always alternate and distichous (in one plane), and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem and a blade with entire (i.e., smooth) margins. The leaf blades of many grasses are hardened with silica phytoliths, which discourage grazing animals; some, such as sword grass, are sharp enough to cut human skin. A membranous appendage or fringe of hairs called the ligule lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath.
Parts of a spikelet Flowers of Poaceae are characteristically arranged in spikelets, each spikelet having one or more florets. The spikelets are further grouped into panicles or spikes. A spikelet consists of two (or sometimes fewer) bracts at the base, called glumes, followed by one or more florets. A floret consists of the flower surrounded by two bracts, one external—the lemma—and one internal—the palea. The flowers are usually hermaphroditic--maize being an important exception—and anemophilous or wind-pollinated. The perianth is reduced to two scales, called lodicules, that expand and contract to spread the lemma and palea; these are generally interpreted to be modified sepals. This complex structure can be seen in the image on the right, portraying a wheat (Triticum aestivum) spikelet.
The fruit of Poaceae is a caryopsis, in which the seed coat is fused to
reference :- http://en.wikipedia.org/wiki/Poaceae
Poaceae have hollow stems called culms plugged at intervals by solid leaf-bearing nodes. Grass leaves are nearly always alternate and distichous (in one plane), and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem and a blade with entire (i.e., smooth) margins. The leaf blades of many grasses are hardened with silica phytoliths, which discourage grazing animals; some, such as sword grass, are sharp enough to cut human skin. A membranous appendage or fringe of hairs called the ligule lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath.
Parts of a spikelet Flowers of Poaceae are characteristically arranged in spikelets, each spikelet having one or more florets. The spikelets are further grouped into panicles or spikes. A spikelet consists of two (or sometimes fewer) bracts at the base, called glumes, followed by one or more florets. A floret consists of the flower surrounded by two bracts, one external—the lemma—and one internal—the palea. The flowers are usually hermaphroditic--maize being an important exception—and anemophilous or wind-pollinated. The perianth is reduced to two scales, called lodicules, that expand and contract to spread the lemma and palea; these are generally interpreted to be modified sepals. This complex structure can be seen in the image on the right, portraying a wheat (Triticum aestivum) spikelet.
The fruit of Poaceae is a caryopsis, in which the seed coat is fused to
reference :- http://en.wikipedia.org/wiki/Poaceae