Rhizophora

Blossom of Red Mangrove ( Rhizophora mangle )

The species of the genus Rhizophora go together with not more closely related species of the genus Avicennia ( subfamily Avicennioideae within the Acanthaceae ) to the most important mangrove trees. They owe their scientific names of the sweeping arc-shaped stilt roots (Greek ῥιζο, Rhizo, " root "; Greek φορός, Phoros, " supporting"). Especially for the widespread species R. mangle the name " Red Mangrove " is used; he is probably referring to the reddish bark and sometimes reddish-brown wood of this Article

The wood of Rhizophora species is used for the production of charcoal and as a building material, the bark is used for the extraction of tannins. A controlled use, taking into account aspects of forest has long been practiced in Malaysia, on the other location but the exception.

Description

Rhizophora species are trees or shrubs of the intertidal zone of tropical coastlines. They have conspicuous stilt roots. The smooth, leathery leaves are undivided, to constantly and entire. On its underside often are numerous lenticels. A pair of stipules enclosing the terminal bud of each drive; the stipules are thrown during the deployment of new leaf pair.

The plants are wind pollinated. The inflorescence arises from the leaf axils and branches of the various species to varying degrees. The flowers are four-fold radial symmetry. The four sepals are strong and united at the base. The four petals are usually hairy and bear in contrast to other Rhizophoraceen no eyelash shaped attachments; they are dropped shortly after the opening of the flower. The filaments of the eight to twelve stamens are reduced, the modified anthers have numerous pollen sacs on. The semi - permanent under ovary has two ovules.

The egg-shaped or conical fruit is brownish or gray - green and leathery tough. As a rule, only a seed that germinates in the fruit on the mother tree developed ( viviparous ). The primary root dies off quickly. The hypocotyl of the seedling penetrates the pericarp, but still connected via the first reformed into a collar-shaped structure of cotyledons with the fruit. The seedling can reach more than 50 cm in length in some species before it is discarded. The seedlings are buoyant and can drift for months in the sea, without the ability for roots to lose.

System

Within the genus six types can be distinguished:

• R. apiculata Blume: Eastern Indo-Pacific
• R. harrisonii Leechm. West Africa, Central and South America
• Red mangrove (R. mangle L. ): West Africa, North and South America; possibly the morphologically very similar Pacific R. samoensis with R. mangle identical
• R. mucronata Lam. Eastern Africa, Indian Ocean, north of Australia, New Guinea, Philippines
• R. racemosa G. Mey. West Africa, South America
• R. stylosa. Handle: Indian Ocean, east of India, the Pacific to Samoa

In addition, the hybrid R. × lamarckii Montrouz be. (R. apiculata × R. stylosa ) and R. × Selala ( Salvoza ) TomL. (R. stylosa × R. samoensis ) described. Also in R. harrisonii it could be a hybrid (R. mangle × R. racemosa ).