Friday 11 May 2012

Marantaceae


The APG II system, of 2003 (unchanged from the APG system, 1998), also recognizes this family, and assigns it to the order Zingiberales in the clade commelinids in the monocots. The Marantaceae are considered the most evolved family in this group due to the extreme reduction in both stamens and carpels.

The family consists of 29 genera with 627 species, found in the tropical areas of the world except in Australia. The biggest concentration is in the America, with seven genera in Africa, and six in Asia.

The plants usually have underground rhizomes or tubers. The leaves are arranged in two rows with the petioles having a sheathing base. The leaf blade is narrow or broad with pinnate veins running parallel to the midrib. The petiole may be winged, and swollen into a pulvinus at the base. The inflorescence is a spike or panicle, enclosed by spathe-like bracts. The flowers are small and often inconspicuous, irregular and bisexual usually with an outer three free sepals and an inner series of three petaloid-like segments, tube-like in appearance. The fruit is either fleshy or a loculicidal capsule.