Ravenea
Encyclopedia
Ravenea is a genus of 17 species of palms
, all endemic
to Madagascar
and the Comoros
.
They are small to large palms, with solitary, robust grey stems, swollen at base and gradually tapering upward. The species vary greatly in size, with R. hildebrandtii and R. nana only reaching 4 m, while R. robustior and R. sambiranensis both reach 30 m. The leaves
are up to 2-5 m long, pinnately compound, reduplicate, erect at first then arching, twisted near the apex; with numerous crowded narrow ribbed leaflets. The inflorescence
is short, borne among the leaves; the fruit
is a red drupe
.
Species
Several of the species are endangered
, R. moorei critically so, with only two specimens known, these last seen in 1993 (IUCN report). R. louvelii is little better off, with fewer than 25 plants known (IUCN report).
Arecaceae
Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...
, all endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
to Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
and the Comoros
Comoros
The Comoros , officially the Union of the Comoros is an archipelago island nation in the Indian Ocean, located off the eastern coast of Africa, on the northern end of the Mozambique Channel, between northeastern Mozambique and northwestern Madagascar...
.
They are small to large palms, with solitary, robust grey stems, swollen at base and gradually tapering upward. The species vary greatly in size, with R. hildebrandtii and R. nana only reaching 4 m, while R. robustior and R. sambiranensis both reach 30 m. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are up to 2-5 m long, pinnately compound, reduplicate, erect at first then arching, twisted near the apex; with numerous crowded narrow ribbed leaflets. The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is short, borne among the leaves; the fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a red drupe
Drupe
In botany, a drupe is a fruit in which an outer fleshy part surrounds a shell of hardened endocarp with a seed inside. These fruits develop from a single carpel, and mostly from flowers with superior ovaries...
.
Species
|
Ravenea madagascariensis Ravenea madagascariensis is a species of flowering plant in the Arecaceae family.It is found only in Madagascar.It is threatened by habitat loss.-Source:* Dransfield, J. & Beentje, H.J. 1998. . Downloaded on 20 July 2007.... Becc. Ravenea moorei Ravenea moorei is a species of flowering plant in the Arecaceae family.It is found only in Comoros.It is threatened by habitat loss.-Source:* Johnson, D. 1998. . Downloaded on 20 July 2007.... J.Dransf. & N.W.Uhl Ravenea musicalis Ravenea musicalis is a species of flowering plant in the Arecaceae family.It is found only in Madagascar.It is threatened by habitat loss.-Source:* Dransfield, J. & Beentje, H.J. 1998. . Downloaded on 20 July 2007.... Beentje Ravenea nana Ravenea nana is a species of flowering plant in the Arecaceae family.It is found only in Madagascar.It is threatened by habitat loss.-Source:* Dransfield, J. & Beentje, H.J. 1998. . Downloaded on 20 July 2007.... Beentje Ravenea rivularis Ravenea rivularis is a species of flowering plant in the Arecaceae family.It is found only in Madagascar.The extremely elegant, fast-growing majesty palm has upward-arching leaves that are divided into long, thin fingers. It makes a fine conservatory feature plant, but make sure the roof is high... Jum. & H.Perrier Ravenea robustior Ravenea robustior is a species of flowering plant in the Arecaceae family.It is found only in Madagascar.It is threatened by habitat loss.-Source:* Dransfield, J. & Beentje, H.J. 1998. . Downloaded on 20 July 2007.... Jum. & H.Perrier Ravenea sambiranensis Ravenea sambiranensis is a species of flowering plant in the Arecaceae family.It is found only in Madagascar.It is threatened by habitat loss.-Source:* Dransfield, J. & Beentje, H.J. 1998. . Downloaded on 20 July 2007.... Jum. & H.Perrier Ravenea xerophila Ravenea xerophila is a species of flowering plant in the Arecaceae family.It is found only in Madagascar.It is threatened by habitat loss.-Source:* Dransfield, J. & Beentje, H.J. 1998. . Downloaded on 20 July 2007.... Jum. |
Several of the species are endangered
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
, R. moorei critically so, with only two specimens known, these last seen in 1993 (IUCN report). R. louvelii is little better off, with fewer than 25 plants known (IUCN report).