In this article we will discuss about:- 1. Characters of Juncaceae 2. Distribution of Juncaceae 3. Economic Importance 4. Affinities.
Characters of Juncaceae:
Herbs, leaves terate compressed, sheathing, often reduced to mere sheath, blade and petiole absent; flower hermaphrodite, bracteate, actinomorphic, hypogynous; perianth segments 6. biseriate, persistent; stamens 6, rarely 3; carpels 3, trilocular, axile placentation; fruit loculicidal capsule.
A. Vegetative characters:
Habit:
Rushlike perennial or annual herbs rarely under shrubs.
Root:
Adventitious hairy roots, fibrous.
Stem:
Erect or horizontal rhizome creeping sympdial rhizome, short.
Leaf:
Basal, tufted, linear, or filiform, grasslike and flat or terete, sheathing basally or reduced to sheath only, sheath either open or closed.
B. Floral characters:
Inflorescence:
Solitary or in panicle, corymb or head like cyme.
Flower:
Usually small, hermaphrodite, sometimes unisexual, if unisexual plants dioecious, hypogynous, actinomorphic, trimerous.
Perianth:
Tepals 6, in two whorls, rarely 3, glumaceous, scarious, or coriaceous, rarely petaloid greenish, whitish, yellowish, or blackish, free, imbricate aestivation, persistent.
Androecium:
Stamens 6, in two whorls, anthers bithecous, filament triangular very slender, short or long, basifixed, introrse.
Gynoecium:
Carpels 3, syncarpous, ovary superior, trilocular with axile placentation or ovary may be sometimes unilocular with parietal placentation style long or absent, ending in into three plamose stigmas usually; ovules many, anatropous, bitegmic.
Fruit:
Loculicidal capsule.
Seed:
Small, sometimes appendaged; endospermic, testa membranous.
Pollination:
Anemophilous.
Floral formula:
Distribution of Juncaceae:
Juncaceae of 8 genera and 315 species which are almost cosmopolitan but most abundant in the temperate and cold regions of Southern hemisphere.
Economic Importance of Juncaceae:
1. Medicinal:
Many species of Luzula are medicinal and are used for kidney diseases.
2. Fibre:
The fibres from the leaf base of Prionium are used in many textile industries, being the source of palmite. The stems of Marsippospermum and Juncus textilis are used in manufacture of mats, choirs, cushions etc.
Affinities of Juncaceae:
The family Juncaceae resembles Liliaceae in typical trimerous, hypogynous flowers and cotyledons behaviour and structure in germination (Eames 1961), the early tip of which acts as a suctorial organ and is retained in the seed like most members of Liliaceae. Juncaceae resembles members of Glumiflorae particularly Cyperaceae in the glumaceous perianth (resembling glumes), feathery stigmas and pollination by means of wind.
Vierhappar (1930) and Rendle (1925) placed Juncaceae and Liliflorae and treated it as a primitive reduced member of the same. Wettstein placed Juncaceae in Enantolasteae (Farinosae of Engler) near Flagellariaceae, similarly Vierhapper and Rendle treated the other two families Restoniaceae and Centrolepidiaceae (other families of order Juncales) as members of Farinosae taking into the mealy nature of endosperm. Fritisch (1909) regards the family Juncaceae very much allied to Cyperaceae. This has been to some extent supported by Eames (1961) as the pollen development in both Juncaceae and Cyperaceae is of ‘Juncus’ type.
Common plants of the family:
1. Juncus bufonius – Toad-rush.
2. Luzula parviflora – Wood-rush.
3. Prionium – restricted to S. Africa.