In this article we will discuss about:- 1. Characters of Marantaceae 2. Distribution of Marantaceae 3. Economic Importance.
Characters of Marantaceae:
Leaves 3-sectioned i.e., sheath, petiole, blade with the peculiar pulviniform ligule, unusual androecial condition with its several staminodes and solitary monothecous anther; 1-3 loculed ovary with a single apparently basal ovule in each fertile locule; the seed arillate with curved or folded embryo.
A. Vegetative characters:
Perennial herbs or shrubs.
Acaulescent, rhizomatous rarely tuberous and sub-terranean.
alternate, petiolate, sheathing lamina usually linear, ovate, oblong or elliptic, pinnate, closely parallel, ligule or pulvinus-like swelling on the stalks; leaf distinguished into sheath, petiole and blade.
B. Floral characters:
Spikes or panicles sometimes scapose usually surrounded or subtended by a spathacous bract.
Zygomorphic, hermaphrodite, epigynous, often in pairs at the axil of bracts.
Tepals 6, in two whorls of 3 each, usually differentiated into calyx and corolla.
3, free and imbricate.
3, connate in an unequally lobed tubular corolla, the posterior corolla lobe is somewhat concave, lobes imbricate.
Stamens of outer whorl are represented by 1 or 2 petaloid staminodes or all the members completely suppressed; in the inner whorl the posterior median stamen as in Canna bear half anther, the other half anther lobe modified into a petaloid appendage, the remaining two lateral stamens of the inner whorl are modified into petaloid staminodes, of which one functions as a labellum and forms a hood over the stigma for time being ‘the staminode cocculatum.’
Carpels 3, syncarpous, ovary inferior, trilocular or unilocular (2 locules being often sterile), ovules 3 or 1 due to abortion of two other ovules, axile placentation; style 1, stout, flat, and twisted, lobed, involute or apically delated, the stigma 1, terminal turncate or depressed.
Loculicidal capsule or fleshy and berry like but dehiscent.
Arillate with mealy perisperm, endospermic.
Distribution of Marantaceae:
Marantaceae or arrow root family represented by 26 genera and 350 species, distributed in the tropics and sub-tropics, but mostly plants of moist, or swamy forest habitats.
Economic Importance of Marantaceae:
The bulbs of Maranta arundinacea yield ‘commercial arrowroot’ a diet for children, due to presence of readily digestible starch.
The tubers of Calathea allouia (West Indies) are edible.
The split stems of Clinogyne dichotoma are woven into mat.
Thallia dealbata, Phrynium are grown as ornamentals.
Common plants of the family:
1. Maranta arundinacea – Arrow-root.
2. Thallia – a popular garden aquatic.
3. Calathea alovia – common in W. Indies.
Division of the family and chief genera:
The Marantaceae is divided into 2 tribes viz.:
Tribe I: Phryneae:
Ovary trilocular, sometimes unilocular, each chamber one ovuled. Genera: Clinogyne, Phrynium etc.
Tribe II: Marantee:
Ovary unilocular, one ovuled only. Genus: Maranta.