Category: Biology Second Paper Lecture Sheet

1. Nature: The plant is annual or perennial herbaceous. Sometimes trees (bamboo).
2. Root: Bunch root.
3. Stem: The stem is cylindrical and hollow in the middle. Sometimes Niret (Akh, Bhutra). The hollow stem is called Culm (rice, wheat, barley, sorghum, cown, bamboo).
4. Leaves: Leaves are simple, alternate, biseriate, sessile, parallel and semi-stemmed. The leaf consists of three parts. Sheath, leaflet and ligule. Leaf veins are parallel.
5. Inflorescence: Inflorescence spikelet. At the base of the spikelet there are two dry glumes. This is called zero gloom. Glum-1 and null Glum-2. Above the null glume are two more flowering glumes. Lemma and Palea. The lower one is called lemma (Greek word lemma means chaff) and the upper one is called palea (Latin word palea means chaff). The flower is above the palea. Lemma can be compared to bract and palea to bractule.
6. Flower: The flower of the grass family is called Puspika. They are unisex or bisexual. Flowering symbionts (Zinia).
7. Perianth: The perianth and panicles of monocots together form a separate organ. It is called inflorescence or perianth. Small leaf-like inflorescences are called lodicules. These are 2 in number, rarely 3 or absent. Plants like betel nut, amlaki, coconut, lily, ulatchandal, kalabati, banana, rajnigandha etc. have flowers.
8. Stamens: Stamens 3, rarely 6 (bamboo, rice). Anthers are two-celled, linear, obovate and split longitudinally. Dr. Siddique Publications
9. Uterus: One chambered uterus, 1 uterus, 1 uterus and 2 uterus. Garbamund feather-like and lateral. Ovary rudimentary and erect.
10. Immortality: Basic.
11. Fruit: caryopsis.
12. Seed: The embryo is tiny and located in one corner of the seed.

1. Leaves with ligules.
2. Leaf veins are parallel.
3. Leaf stem.
4. The stem is cylindrical and hollow in the middle.
5. The flowers are polymorphic and bisexual.
6. Flowers trimerous i.e. the number of petals in a flower is 3 or a multiple of 3.
7. Inflorescences are present and are known as lodicules.
8. Inflorescence spikelets.
9. The coat is linear and versatile.
10. The womb is like a feather.
11. Arrangement is key.
12. Fruit caryopsis.
13. The seeds are sessile, the embryos are microscopic-located in one corner of the seed and contain starch grains.

The family Poaceae is named after the Greek word Poa meaning grass. Poaceae or Gramineae is the largest family of monocots. In 1895, John Hendley Barnhart named the family Poaceae. Poaceae or grass family consists of 500 genera and 8000-9000 species. 113 genera and 285 species of this tribe have been identified in Bangladesh. 20% of the earth’s land is covered by this genus of plants.

1. Their seeds have only one cotyledon.
2. Leaf veins are parallel.
3. Flowers trimerous i.e. the number of petals in a flower is 3 or a multiple of 3.
4. root root.
5. The location of the carpels is apical and the embryo is lateral.
6. Seed coat and fruit coat are attached together.
7. The flowers are incomplete and the perianth remains.
8. The vascular bundles of the stem are scattered. Cambium tissue is absent.
9. Secondary growth does not occur.
10. Pollen monocolpate (one grooved).

Herbaceous plants whose seeds have only one cotyledon are called monocots. The family of monocotyledonous plants is called monocotyledonous family. Dr. Arthur Cronquist (1981) grouped all herbaceous plants into 380 genera. Among them, the number of monocots is 65. Butomaceae is the first family of monocots, Poaceae is the 34th family and Orchidaceae is the last 65th family.

The axis from which flower is formed is called mother axis. The side opposite to where the flower is attached is called Axis.

Sepals 5 and free, sepals 5, connate, and valvate, petals 5, free and twisted, stamens numerous, gregarious and connate, anthers free, carpel subgynate, 5-celled, carpels 5 and connate, anthers axillary. Floral symbols indicate that the flower is polysymmetric, bisexual and pentamerous.

Anthers and subanthers present, carpels 2 and free, stamens 6, 3 in two whorls and free, ovary subgynous, 1-chambered and carpel 1. Arrangement is key. The floral symbols show that the flower is unisexual, bisexual and trimerous.

The diagram that shows the gender of the flower compared to the mother axis, the different stanzas, the number and position of members of each stanza, their synergism or dissociation, the presence or absence of stamens, floral arrangement, amara arrangement etc. is called Floral diagram. In 1778, the German botanist August Wilhelm Aicher described the first floral symbols.

Flower polysymmetric and both sexes, sepals 5 and free, sepals 5 and connate, petals 5 and free, stamens numerous, gregarious and connate, ovary superior, 5-chambered, carpels 5 and connate.