Monocotyledon families- Alismaceae, Cyperaceae and Gramineae

Alismataceae or Alismaceae

(Water plantain family)

Represented by about 14 genera and over 90 species, Alismataceae are cosmopolitan in distribution. About 7 genera and 10 species have been reported from India. 

Chief genera are:

• Echinodorus (burhead), 
• Sagittaria (arrowhead), 
• Alisma (water plantain) and 
• Damasonium. 

Selected Indian genera are: 

• Alisma, 
• Limnophyton and 
• Sagittaria.

                Plants from this family are annual or perennial, aquatic or marshy herbs with a stout perennating rhizome, roots are fibrous, and stem is thin, erect or with floating leaves; in Sagittaria the runners terminate into tubers; usually the latex is present in stems and leaves. Bisexual flowers; perianth biseriate with 3 free sepals and 3 free petals; many free carpels.

Fruits and seeds: Fruit a group of achenes arranged spirally or in ring. Seeds with a horse-shoe shaped or curved embryo and without endosperm.

Pollination and dispersal: Flowers are entomophilous, and get pollinated by flies, short-tongued bees and other similar insects which visit them in search of nectar. Dispersal of seeds takes place mainly by water and partly by air.

Economic Importance

Economically the family is not of any special significance. Sagittaria rhizomes are sometimes grown for their food value and used as food under the name "swamp potato". Tubers of Alisma plantar-aquatic and corms of Sagittaria sagittifolia are edible. Some species of Sagittaria and Alisma are used as aquarium plants. Some species of Alisma, Echinodorus and Sagittaria are planted for decoration beside ponds and streams.

Cyperaceae

(Sedge family)

A family of approximately 90 genera and over 4000 species, showing worldwide distribution in damp and wet habitats. About 23 genera and over 400 species have been reported from India. 

Larger genera of the family from the world are: 

• Carex (Carex or sedge), 
• Cyperus (sedge), 
• Fimbristylis, 
• Scirpus (bulrush), 
• Rhynchospora (beak rush), 
• Eleocharis (spike rush), 
• Scleria (nut rush), 
• Schoenus and 
• Uncinia. 
• Cyperus papyrus used for paper- making by Egyptians even as early as 2400 B.C. and C. rotundus a serious weed of lawns and fields are two important plants of the family.

           Plants of this family are annual or perennial, grass-like herbs found in damp or wet places; persisting usually by a creeping, underground, sympodial rhizome. Stem often called 'culm', the aerial stem is often triangular, solid or rarely hollow, leafless and generally unbranched below the inflorescence. Leaf, grass-like. often develop in a crowded tuft on lower basal part of the culm.

Fruits and seeds: Fruit a triangular or biconvex achene or nutlet. Seed one per fruit, with small embryo, embedded in fleshy or mealy endosperm; seed coat free from the pericarp.

Pollination: Flowers are usually wind-pollinated, although pollen-eating beetles may also transport pollen grains in some species of Carex. Several Carex species are protandrous.

Economic Importance

Sedges are not of much significant importance. However, some are grown as ornamentals, few are used in medicines and some are even edible. Several of them are noxious weeds 

(Cyperus rotundus) of lawns and cultivated fields. Some aspects of their economic importance are:

1. Starchy tubers of some members are edible, e.g. Cyperus esculentus (Tiger-nut), C. bulbosus and Eleocharis dulcis (Chinese water chestnut).
2. Tubers of Cyperus rotundus are used in stomach disorders, while that of  C. articulates are used as tonic, and that of C. stoloniferous are considered as stimulant for heart. Tubers of C. scariosus are used in treating stone trouble of kidney and urinary bladder.
3. Chufa-oil obtained from the tubers of Cyperus esculentus, is used in soap industry.
4. Tubers of Cyperus rotundus and C. scariosus are used in the preparation of fragrant sticks called "Agarbattis" in India.
5. Cyperus papyrus (papyrus plant), formerly used in paper making, is nowadays grown as an ornamental plant. Other plants of ornamental value are C. flabelliformis syn. C. alternifolius (umbrella plant), C. fertilis and C. gracilis.
6. Culms of Cladium mariscus, Cyperus corymbosus, C. elatus, C. exaltatus, C. iria, etc. are used for making mats, baskets, etc.
7. Several species of Cyperus, Carex, Scirpus, Rhynchospora, etc are used as fodder, though of inferior quality.

Gramineae or Poaceae
(Grass family)

Bamboo

Gramineae, the largest and most important family of angiosperms from the economic point of view, is represented by about 620 genera and over 10,000 species, and distributed widely in almost all regions of the world and in almost every type of habitat. About 240 genera and over 1200 species have been reported from India. 

Some largely represented genera are: 

• Panicum (panic grass), 
• Digitaria (crab grass), 
• Aristida (wire grass), 
• Poa (blue grass), 
• Eragrostis (love grass), 
• Stipa (needle grass), 
• Paspalum (Bahia grass), 
• Agrotis (bent grass), 
• Arundinaria (giant cane), 
• Pennisetum (Bajra), 
• Setaria (Italian millet), 
• Agropyron (wheat grass), 
• Muhlenbergia (bull grass), 
• Arena (oats), 
• Sorghum (sorghum), 
• Oryza (rice), 
• Triticum (wheat), 
• Hordeum (barley), 
• Saccharum (sugarcane), 
• Cynodon (Doob grass), 
• Zea (maize). 

Selected Indian genera are: 

• Avena, Bambusa, 
• Cynodon, Hordeum, 
• Oryza, 
• Poa, 
• Saccharum, 
• Secale, 
• Sorghum, 
• Triticum and 
• Zea.

                            Plants of this family are usually annual or perennial herbs, rarelywoody shrubs or tree like reaching up to a height of 30 metre (Bambusa) or even more. They have round stem (culm) having usually hollow internodes; leaves mostly flat, 2-ranked and usually with open leaf sheath; ligule usually present; bracts of lames, lemma and pale; fruit caryopsis.

Inflorescence: Basic unit of inflorescence is a spikelet; each spikelet consists of one or more flowers (or florets) and their subtending bracts arranged on an inflorescence axis called rachilla, spikelets are either sessile or with pedicel, and arranged in spikes, racemes or panicles forming compound inflorescences; at the base of each spikelet are generally present two sterile plumes, of which the lower one is called first glume and the upper one is called second glume, in some genera, either the first glume or both the first and second glumes are absent; unto six sterile glumes are present in some genera; the flowers are arranged on the rachilla just above the second glume.

Flowers, also called florets are small, inconspicuous, bisexual or unisexual (Zea), zygomorphic, hypogynous; develop on rachilla above the glumes; and each floret is subtended by two bracts called lemma and palea; lemma also called fertile or flowering glume, is greenish, keeled, nerved or awned, and often resembles with sterile glumes; palea, present in between rachilla and lemma, is thin, membranous, 2-nerved or 2-keeled and often partially enclosed by the lemma. Palea morphologically resembles a bracteole, bears a flower proper in its axil.

Pollination: Plants, such as Triticum, are self-pollinated whereas majority of grasses are wind-pollinated. Flowers are protogynous. Characters such as small and inconspicuous flowers, and feather- like stigma are the adaptations for anemophily. Flowers produce loose and powdery pollen grains in large quantity.

Economic Importance

Gramineae are of greater importance than any other family of flowering plants from the economic point of view. Plants of this family provide food for man (wheat, oat, barley, sugarcane, etc.), fodder for our domestic animals, grasses and ornamental plants for our lawns and gardens, and several other products including starch, ethyl alcohol, paper, fibres, edible oils, adhesives, thatching and building materials, wildlife food, etc.

1) Cereals:

 

Avena sativa (oats): This important cereal and fodder crop is highly nutritious.

Hordeum vulgare (barley): Used as a feed grain and also in manufacturing several alcoholic beverages including beer, barley water, etc.

Oryza sativa (Rice): Used as a common staple food by millions of people throughout the world, rice is also used as livestock and for manufacturing paper, alcohol, starch etc. Its husk is used as fuel and its bran is the source of fatty oil.

Secale cereale (Rye): Besides its limited use as a cereal crop, rye is used for making alcoholic beverages, pickles, sambar, etc.

Triticum aestivum syn. T. vulgare (wheat): Wheat is often used universally as a staple food for man. Its straw is used as stockfeed for cattle, for packing goods, and for manufacturing paper. Grains are also used for manufacturing starch, industrial alcohol, etc. 

Zea mays (Maize): Used as a common food by man, maize is also used as livestock feed for cattle and also for manufacturing several industrial products such as explosives, adhesives, soaps, starch, plastics, asbestos, linoleum, etc. Paper is manufactured from its leaf stalks, and the corn oil is used in preparing paints, varnishes, etc. Several alcoholic beverages are also manufactured from maize.

2) Millets: 

 

Millets used as coarse grains by man and common fodder for animals, belong to Gramineae. Some of the important millets include 

• Eleusine coracana (Ragi or finger millet),
• Panicum miliaceum (common millet), 
• Pennisetum typhoides (bajra or pearl millet),
• Setaria italica (Italian millet),
• Sorghum vulgare (Jowar or sorghum).

Jowar and bajra are chiefly used for poultry and cattle, and also for preparing alcoholic beverages and diastase.

3) Sugar:

It is obtained from the stem juice of Saccharum officinarum (Sugarcane). Baggage is used for manufacturing paper while the molasses is utilised for manufacturing industrial alcohol and alcoholic beverages such as rum. 

4) Fodder: The whole aerial green part of several members of gramineae is cut and used as green fodder. Several species of some commonly used genera for this purpose belong to Avena, Eleusine, Hordeum, Pennisetum, Phalaris, Setaria and Sorghum.

Almost all wild grasses are browsed by the cattle, of which some commonly browsed species are:

• Andropogon pertusus
• Apluda mutica
• Cenchrus ciliaris
• Cynodon dactylon
• Dichanthium annulatum
• Iseilema taxum
• Panicum maximum

Straw of various species of Oryza and Triticum is also used as a common fodder for cattle.

Some other fodder grasses are:

• Dactylis glomerata
• Heteropogon contortus
• Lolium multiform
• Paspalum scrobiculatum
• Poa annua
• Sporobolus diander
• Stipa orientalis

5) Lawn grasses:

Many grasses are used in lawns and other turfed areas, e.g. Agrostis, Cynosurus, Fistula, Lolium and Poa.

6) Paper manufacturing: Pulp, prepared from the straw of several species of this family, is used in manufacturing paper of almost all coarse and fine qualities, strawboard, artificial rayon, etc. Some commonly used genera for the purpose are:

• Bambusa
• Cephalostachyum
• Dendrocalamus
• Erianthus (E. arundinaceus, E. munja, E. ravennae)
• Gigantochloa
• Melocanna
• Narenga
• Ochlandra
• Oryza
• Saccharum (S. benghalense, S. officinarum, S. procerum, S. spontaneum)
• Triticum aestivum
• Vetiveria zizanioides
• Zea mays

Bamboos:

 'Bamboos' a common term used for some tall tree- like woody grasses, are universally used for papermaking. They are also used for house building, as a substitute of timber, and also for preparing several other articles such as walking sticks, beds, tent poles, umbrella handles, kites, musical instruments, furniture, toys, mats, etc. Some bamboos are harvested for cattle fodder, and several other are grown for checking soil erosion, and also for ornamental purposes. Some common bamboos are:

• Arundinaria
• Bambusa
• Cephalostachyum
• Dendrocalamus
• Melocanna
• Ochlandra
• Phyllostachys

Khus-Khus: Roots of Vetivaria zizanioides are used for making curtains and screens, which when wetted, bring about cooling and scenting of rooms.

Essential oils: Volatile oil, obtained from the leaves of several grasses is used in perfumery, medicines, mosquito-repellant creams, soaps, etc. Some grasses utilised for the purpose are:

• Cymbopogon caesius (ginger grass oil)
• C. citratus (lemon grass oil)
• C. martinii (palmarosa oil)
• C. nardus (citronella oil)
• Vetiveria zizanioides (thus oil or oil of vetiver)

Ornamental plants: Grasses, grown for ornamental purposes in the gardens or dried and used for floral decoration, include:

• Axonopus affinis (carpet grass)
• Briza maxima (quaking grass)
• Coix lacrimal-jobi (job's tears)
• Cortaderia selloana (Pampas grass)
• Cynodon dactylon (Doob grass or Bahama grass)
• Lagurus ovatus (Hare's tail grass)
• Lamarckia aurea (golden top grass)
• Phalaris arundinacea (ribbon grass)
• P. canariensis (canary grass)
• Setaria italica (Foxtail millet)
• Stipa pinnata (feather grass)

11) Brooms: Panicles of Thysanolaena maxima (Broom grass) are used as soft brooms.

12) Ropes, mats, baskets: Ropes are made from the fibres obtained from the leaves of Erianthus munja syn. Saccharum munja (munj) and Saccharum spontaneum (kaans) while mats, baskets, musical instruments, etc. are prepared from the stems of Arundo donax (reed), Arundinaria falcata, A. racemosa and Phragmites karka (bans or common reed).