Terrestrial rhizomatous herbs, sometimes lianescent and high-climbing, very variable in development of aerial shoots. Leaves distichous, segregated into sheath, petiole proper (often missing), pulvinus and blade; blade with a strong midrib and thin, parallel and closely set lateral veins, these ± sigmoid, fusing marginally, interconnected by closely set, parallel transverse veinlets. Inflorescence terminal or lateral, simple or a ± complex synflorescence; inflorescence unit (florescence) or usually spiciform or capitate thyrse with distichous or spiral spathes (bracts) subtending ± elaborate flower clusters composed of I-several (rarely numerous) 2-flowered cymules (1-flowered in Monotagma and Monophrynium), each with a prophyll on the dorsal side at base, sometimes also with a scale-like interphyll on the ventral side and 1 or 2 ± dorsal bracteoles (additional lateral bracteoles in one species of Calathea). Flowers perfect, epigynous, pentacyclic, heterochlamydeous, completely asymmetric (the 2 flowers of a pair being mirror images); sepals distinct; petals, androecial elements, and style fused to form a floral tube (corolla tube) greatly variable in length. Outer androecial whorl rarely missing, usually of 1 or 2 staminodes, which are usually petaloid and showy, but sometimes acicular, or ± rudimentary; inner androecial whorl of 3 members, 1 fertile monothecic stamen (often with a petaloid appendage), 1 hood-shaped staminode (staminodium cucullatum), and 1 conspicuously firm and fleshy staminode (staminodium callosum); the inner staminodes basally fused to form a firm and fleshy staminal tube which ± exceeds the level where the corolla lobes separate from the floral tube. Ovary 3-carpellate and 3-locular, but 2 locules often empty and compressed; fertile locule(s) I-ovulate with the anatropous ovule inserted at base; septa with completely sunken septal nectaries. Style fused basally with the floral tube, in mature untriggered flowers the style enclosed in the hood of the cucullate staminode, bent backwards and held under tension; when released by a pollinator, snapping forward and curling up in a circinate or (Thalia) helical fashion; stigmatic surface restricted to the inner side of a funnel-shaped depression in the apex of the style. Fruit usually a loculicidal capsule, more rarely berry-like (Sarcophrynium, Thaumatococcus), or caryopsislike (Thalia). Seeds rather large (3-20mm), without endosperm at maturity, embryo horseshoe-shaped, embedded in copious starchy perisperm; perisperm with a simple or forked, central canal running from base to the level of the embryo bend, or slightly further.
Most species are confined to tropical rainforest habitats at altitudes below 1000m, where they show a considerable amount of ecologic diversification. They are mainly jungle weeds in the sense that they require some degree ofdisturbance in order to flower and fruit. Rather few are true understorey species flowering and fruiting in deep shade (e.g. Monophyllanthe oligophylla, some Calathea spp.). Some species, usually small to medium, germinate and persist in a vegetative state in the full shade of a closed canopy, being ready to flower as soon as opportunity arises. Others, usually larger species, are unable to grow for long in deep shade, but complete their life cycle in larger light gaps of longer duration, such as are caused by landslides, extensive storm felling etc. Relatively few species are able to persist in permanent openings such as stream margins, etc. Species of the two latter categories often show good ability to invade secondary habitats, while the species of small light gaps mostly perish where forests are cut over. Some few species occur in semideciduous and deciduous forests (e.g. Maranta arundinaeea). They show a highly seasonal pattern of growth, often dying back to the rhizome in the dry season. The genera Thalia and Halopegia (H. azurea, at least) are confined to open marshes. Alarger number of species (in Calathea, Isehnosiphon, Monotagma) have their primary habitats in swamp forest and riverine inundation forest (igapó and varzea).
The Marantaceae are nearly exclusively tropical, albeit a few species slightly exceed the tropics in N and S America. The majority of species are neotropical, i.e. about 450, some 300 of which are contributed by the genus Calathea alone. Four major ranges may be discerned in the Americas, one comprising the Pacific lowlands and western Andean slopes, and Central America north to Guatemala and S Mexico; one comprising the eastern Andean slopes and western Amazon Basin from Bolivia to central Colombia; one including the Guianas and the eastern Amazon Basin; and one comprising the coastal rain forest of SE Brazil. The African distribution extends from Sierra Leone to Sudan, Uganda and Zimbabwe, but is heavily centred in the west. The Asian range extends from Sri Lanka and Assam to Formosa and the Philippines, but is pronouncedly centred in the Indomalesian area.
The only important crop plant of the family is Maranta arundinacea, cultivated for the high-quality starch of the rhizomes. Several species of Calathea (e.g. C. laneifolia, C. makoyana) and Maranta (e.g. M. bicalor, M. leueoneura) are economically important ornamentals in common trade. A much larger number of species of Calathea, Maranta, Saranthe and Ctenanthe occur occasionally in horticultural trade, but have little significance economically, since they are impossible to cultivate indoors without special arrangements. It seems, however, that the importance and diversity of Marantaceae as ornamentals in tropical and subtropical horticulture is rapidly increasing. In aboriginal economy, a fairly large number of species are used. Many species of Calathea and Maranta with tuberous roots are locally cultivated, and inflorescences of several Calathea spp. are cooked and eaten by the natives in Central America (Kennedy 1978). Split stems of tallgrowing species of Isehnosiphon are used for basket-weaving and the leaf blades of many larger species are used for wrapping up food items.
With kind permission from Springer Science+Business Media: This work is subject to copyright. All rights reserved, whether whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, broadcasting reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under German Copyright Law.All Rights Reserved