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In this article we will discuss about:- 1. Characters of Cyperaceae 2. Distribution of Cyperaceae 3. Economic Importance 4. Affinities 5. Important Type.
Characters of Cyperaceae:
Plants usually herbs with 3 angled stem, solid culm; leaves with entire sheathing base not split on one side; flowers in spikelets of cymes, subtended by a single glume, naked or with perianth of scales or hairs; stamens 1 to 3; carpels 2 or 3, ovary superior, unilocular with single basal ovule; fruit an achene or nut, seed endospermic.
A. Vegetative characters:
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Habit:
Plants are commonly perennial herbs rarely annual; perennating by means of creeping rhizomes or tubers. The members are inhabitants of damp places.
Root:
Adventitious, fibrous, branched or tuberous.
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Stem:
Underground rhizomes, tubers or stolons, aerial shoots terete (angled), solid glaucous or glabrous, without distinction into nodes and internodes; usually unbranched rarely branched near the tip.
Leaves:
Exstipulate, sessile, leaf base sheathing, sheath closed, eligulate, arranged in three rows, alternate, simple, lamina linear, narrow, pointed, sharply edged.
B. Floral characters:
Inflorescence:
Inconspicuous flowers arranged in spikelets, panicles or in spikes of cymose rarely solitary terminal (Oreobolus).
Flower:
Sessile, bracteate, zygomorphic hermaphrodite or unisexual arising in the axil of a single glume, hypogynous, small.
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Perianth:
Usually absent but in some represented by hairs or scales (Oreobolus); flowers naked (Cyperus, Carex).
Androecium:
In male or hermaphrodite flowers stamens usually 3, may be 1 to 6 or one (Hemicarpa), polyandrous; anthers dithecous, basifixed, oblong or linear; filaments long and thread-like.
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Gynoecium:
In female flowers or hermaphrodite flowers gynoecium is bicarpellary (Rhyncospora) or tricarpellary (Carex), syncarpous, superior, unilocular, single basal ovule; style single or divided into the equal number of carpels; stigma linear or feathery corresponding to the number of carpels. In Kobresia ovary is enclosed in a bract or utricle.
Fruit:
A flattened 3-angled nut.
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Seed:
Endospermic.
Distribution of Cyperaceae:
The family is commonly known as ‘Sedge family’. It is distributed throughout the world but most abundant in temperate zones. It comprises 70 genera and 4000 species. In India it is represented by 441 species.
Economic Importance of Cyperaceae:
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The family is of little economic importance.
1. Food:
The tubers of Cyperus esculentus (H. Kaseru) are used as food due to their high oil content. The tubers yield 25 to 30% oil of pleasant taste. The tubers of Eleocharis tuberosa are also edible.
2. Fodder:
Many species of Cyperus are taken by cattle as fodder.
3. Medicinal:
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The tubers and rhizomes of Cyperus articulatus, C. iria, C. longus are carminative, stimulant and tonic. The tubers of Cyperus stoloniferous are stimulant for heart.
The tubers of Scirpus kysoor, S. grossus are used in diarrhoea and vomitting. Scirpus articulatus is purgative.
Kyllingia triceps is used in diabetes.
4. Poisonous:
Carex cernua is cattle poison.
5. Other uses:
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Carex arenaria and species of Cyperus are good sand binders.
Scirpus lacustris is used for matting. Aromatic scented oil is obtained from Cyperus stoloniferous.
6. Ornamentals:
Cyperus alterifolius and Isolepis are cultivated in gardens.
Primitive characters:
1. Leaves are simple, alternate with sheathing base.
2. Flowers are hypogynous, hermaphrodite and bracteate.
3. Flowers are actinomorphic.
4. Ovary superior.
5. Seeds are endospermic.
Advanced characters:
1. Plants are herbs, mostly annuals.
2. Leaves are exstipulate.
3. Flowers are small and arranged in spikelets.
4. Flowers are zygomorphic in Scirpus.
5. Perianth lobes are absent or represented by hairs.
6. Reduction in the number of stamens.
Affinities of Cyperaceae:
The family Cyperaceae closely resembles Poaceae (Gramineae), hence most of the taxonomists have included it with Poaceae (Gramineae) under Glumiflorae. Hutchinson and Wettestein placed the family Cyperaceae in a separate monotypic order Cyperales and considered it to have been derived from the members of Juncales or Juncaceae on parallel line with Poaceae (Gramineae).
Snell, R.S. (1936) and Blasser, H.W. (1940) indicated that Cyperaceae is not related to Poaceae (Gramineae).
Blasser stated that:
1. The superficial grass-like habit is of no phylogenetic significance.
2. Spikelets of Cyperaceae are not homologous with that of the Poaceae (Gramineae).
3. In Cyperaceae florets are borne axillary while in Poaceae (Gramineae) they are terminal in position.
4. The basal placentation in Cyperaceae has been derived from an ancestral free general type, while in Poaceae (Gramineae) it has been derived from a parietal.
5. In Cyperaceae the embryo is embedded at the base of endosperm while in Poaceae (Gramineae) outside it.
So both the families should be placed in separate orders i.e. Cyperales and Graminales as done by Hutchinson.
Common plants of the family:
1. Cyperus rotundus (ordinary sedge):
A weed of cultivated lands.
2. Carex:
Leaves of many species have sharp and saw-like edges.
3. Eriophorum cosmusum (Cotton sedge):
A glabrous herb with long perianth hairs used for stuffing.
4. Fimbristylis:
A weed having glabrous stem.
5. Kyllinga:
A perennial glabrous herb common in Western Himalayas.
6. Scirpus (Club-rush or bull rush):
A perennial herb found in bogs and marshes.
Division of the family and chief genera:
Engler divided the family as follows:
Sub-family I. Scirpoideae:
Flowers hermaphrodite, without perianth, e.g., Scirpus, Cyperus.
Sub-family II. Caricoideae:
Flowers unisexual and naked in many flowered spikes e.g., Carex.
Sub-family III. Rhyncosporoideae:
Flowers hermaphrodite or unisexual, with or without perianth e.g., Rhyncospora. Hutchinson divided the family into seven tribes.
Important Type of Cyperaceae:
Scirpus articulatus (Fig. 117.1):
Habit:
A glabrous perennial herb.
Root:
Adventitious.
Stem:
Herbaceous, 1 to 3 ft. long, densely tufted, fistular, green, terete, trigonous, striate, transversely separate.
Leaves:
Absent or the sheaths with a membranous acute tip.
Inflorescence:
Terminal or lateral spikelets with glumes.
Flower:
Hermaphrodite, zygomorphic, complete, hypogynous, trimerous.
Perianth:
Represented by hypogynous bristle or scale.
Androecium:
Stamens 3, polyandrous, anthers linear, obtuse, yellow, introrse, dithecous, basifixed.
Gynoecium:
Tricarpellary, syncarpous, ovary superior, unilocular, single basal ovule; style long; slender; stigma trifid, feathery.
Fruit:
Trigonous nut.
Seed:
Endospermic.
Floral formula:
