Poaceae

B.Sc. II Year
“ANGIOSPERMS SYSTEMATIC, ANATOMY AND EMBRYOLOGY”
Unit – III
‘Angiosperms Systematic’
Family- Poaceae
DR. SWATI V. PUNDKAR
Assistant Professor
Department of Botany
Shri Shivaji Science College, Amravati
NAAC Accredited ‘A’ Grade

Engler and Prantls classification
Division – Phanerogams
Sub division- Angiospermae
Class- Monocotyledonae
Order – Glumiflorae
Family – Graminae/ Poaceae

Characters of Poaceae:
Mostly herbs, stem jointed, fistular, cylindrical; leaves simple, alternate,
sheathing, sheath open, ligulate; inflorescence compound spike; flowers
zygomorphic, hypogynous, protected by palea; perianth represented by
2 or 3 minute scales (lodicules); stamens 3, versatile; carpel one, style 2
or 3, stigmas feathery, basal placentation; fruit caryopsis; testa fused
with pericarp.
Distribution of Poaceae:
The family is commonly known as grass family. It is one of the largest
among the angiospermic families. It consists of 620 genera and 6,000
species. The members are cosmopolitan in distribution. The plants
represent all the 3 ecological types as hydrophytes, xerophytes and
mesophytes. In India it is represented by 850 species

Plant list of Poaceae
1) Triticum aestivum – Wheat
2) T. vulgarius – Jawar
3) Zea mays – Maka
4) Pennisetum Americanum – bajara
5) Saccharum officinarum- Sugarcane
6) Oryza sativa – Rice
7) Hordeum vulgare – Barlay
8) Avena sativa – Oat
9) Cymbopogon martini – Ginger grass
10)C. nardus – Citronella grass
11)Cynodon dactylon – doob grass
12)Dendrocalamus sp. – Bamboo
13)Bambusa sp. - Bamboo

Primitive characters:
1. A few plants arboreal in habit.
2. All florets in a spikelet are
fertile.
3. Glumes are persistent.
4. Lemmas are herbaceous and
leafy.
5. Stigmas are three.
6. Leaves are simple and
alternate.
7. Flowers are hypogynous and
hermaphrodite.
8. Seeds are endospermic.
Advanced characters:
1. Plants are mostly herbaceous, annuals
and perennials.
2. Leaves are exstipulate.
3. Flowers are arranged in distinct
inflorescence.
4. Flowers are small, incospicuous and
zygomorphic.
5. Perianth is represented by lodicules.
6. Stamens are reduced to 3.
7. Gynoecium is monocarpellary and
unilocular.
8. Basal placentation.
9. Fruit is caryopsis.
10. Seeds are small sized.

Habit:
Herbs, annuals or perennials or shrubs, sometimes tree like (Bambusa,
Dendrocalamus).
Root:
Adventitious, fibrous, branched, fascicled or stilt (Zea mays).

Stem:
Underground rhizome in all perennial grasses, cylindrical, culm with
conspicuous nodes and internodes, internodes hollow, herbaceous or
woody, glabrous or glaucous, vegetative shoots are arising from the base
of aerial stem or from underground stems are called tillers.

Leaves:
Alternate, simple, distichous, exstipulate, sessile, ligulate (absent in
Echinochloa), leaf base forming tubular sheath, sheath open, surrounding
internode incompletely, ligule is present at the junction of the lamina and
sheath, entire, hairy or rough, linear, parallel venation.

Inflorescence:
Compound spike which may be sessile or stalked. Each unit of inflorescence is spikelet. The spikelets are
arranged in various ways on the main axis called rachilla. A compound inflorescence may be spike of
spikelets (Triticum), panicle of spikelets (Avena).
The spikelet consists of a short axis called rachilla on which 1 to many sessile or short stalked flowers are
borne. The florets may be arranged in alternate or opposite manner on the central axis.
At the base of rachilla two sterile scales, called glumes, are present. The glumes are placed one above the
other on opposite sides. The lower one is called first glume and the upper is called second glume. Both
the glumes are boat shaped and sterile. Above the glumes a series of florets are present. Each floret has
an inferior palea or lemma and above it a superior palea. The lemma frequently bears a long, stiff hair
called awn.

Flower:
Bracteate and bracteolate, sessile, incomplete, hermaphrodite, or unisexual (Zea
mays), irregular, zygomorphic, hypogynous.
Perianth:
Represented by membranous scales called the lodicules. The lodicules are situated
above and opposite the superior palea or may be absent, or many (Ochlandra), or 2 or 3.

Androecium:
Usually stamens 3, rarely 6 (Bambusa, Oryza) and one in various species of Anrostis,
Lepturus; polyandrous, filaments long, anthers dithecous, versatile, linear, extrorse;
pollen grains dry.

Gynoecium:
Monocarpellary, according to some authors carpels 3, of which 2 are abortive, ovary
superior, unilocular with single ovule, basal placentation, style short or absent; stigmas
two feathery or papillate and branched.

Fruit:
Caryopsis (achene with pericarp completely united or adherent with the seed coat) or
rarely nut (Dendrocalamus) or berry (Bambusa).
Seed:
Endospermic and containing a single cotyledon called scutellum, which is shield shaped
and pressed against the endosperm.

Economic Importance of Poaceae:
The family stands first and foremost in respect of economic importance in whole of
Angiosperms. The staple food grains of the population of world is derived from Oryza
sativa (Rice) and Triticum aestivum (Wheat). They are cultivated from time
immemorial.
The family has been divided on economic basis as follows:
Food:
Triticum aestivum, Oryza sativa, Zea mays (Maize), Hordeum vulgare (Jaw), Sorghum
vulgare (Jowar), Avena sativa (Oats), Pennisetum typhoides (Bajra) are cultivated for
cereals and food grains.
Fooder:
Many grasses as Cynodon dactylon, Panicum, Cymbopogon, Agrostis, Poa are grown
for fodder.
Sugar:
Saccharum officinarum (Sugarcane; H. Ganna) is cultivated for gur and sugar.
Building material:
Some species of Bambusa e.g. B. tulda, B. vulgaris are used for scaffolding, thatching
huts etc.

Furniture:
Species of Dendrocalamus (H. Bent), Arundinaria, Melocalamus are used in manufacture of furniture.
Aromatic grasses:
Many grasses yield scented oils which are used in perfumery viz. Vetiveria zizanioides (H. Khus khus)
yields vetiver oil from the roots. The roots are also woven into curtains. Andropogon odoratus (Ginger
grass), Cymbopogon citratus (Lemon grass), Cymbopogon martini (Geranium grass), Cymbopogon
jawarancusa etc. also yield oil.
Medicinal:
Phragmites karka, Cymbopogon schoenanthus etc. are medicinal.
Secale cereale is cultivated for infection of its inflorescence by Claviceps purpurea for production of Ergot
and for extraction of ergotine. Ergotine is an excellent remedy for uterine contraction.
Paper:
It is manufactured from certain species of grasses and bamboos.
Ornamental:
Rhynchelytrum repens, Cortaderia selloana and some species of the tribe Bambusoideae are
ornamentals.
Besides these a number of grasses are grown to form fine lawns, play grounds etc.

Poaceae

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