Rauvolfia nukuhivensis
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Branch with opened and still closed flowers of Rauvolfia nukuhivensis |
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| Rauvolfia nukuhivensis | ||||||||||||
| ( Fosberg & Sachet ) Lorence & Butaud |
Rauvolfia nukuhivensis , syn .: Ochrosia nukuhivensis Fosberg & Sachet, is a species of plant from the subfamily of the Rauvolfioideae in the family of the dog poison plants (Apocynaceae). It is endemic only to Nuku Hiva Islandin the Marquesas Islands in the South Pacific . It was considered extinct from 1998 until it was found again in 2002.
description
Vegetative characteristics
Rauvolfia nukuhivensis grows as a tree that can reach heights of 8 to 15 meters and a diameter of 40 to 50 centimeters at chest height . The furrowed bark is pale orange to brown. The bare and wrinkled bark of the branches is brown to greyish-brown. The deciduous branches are 3 to 3.5 millimeters thick, while branches that do not have foliage are about 6 millimeters thick. The milky juice is white.
The alternate leaves on the branches are divided into a petiole and a leaf blade. Brown hairs 1 to 2 millimeters long are found on the leaf axis and at the base of the petiole. The leaf stalk, which is flattened at the top, is 1.2 to 3.6 inches long and 1.2 to 1.5 millimeters thick. The simple, bald and parchment-like leaf blade is egg-shaped, elliptical to oblong-elliptical with a length of 6 to 17.6 centimeters and a width of 1.5 to 6.2 centimeters. The base of the spreader tapers in a wedge shape, the tip of the spreader is pointed and the edge of the spreader is slightly rolled down. The leaf blade is pale green in color. From each side of the leaf central nerve, 21 to 25 lateral veins branch off .
Generative characteristics
Terminally on a bare inflorescence stem trichotomously branched, zymous inflorescences are 5 to 7 centimeters long and 7 to 10 centimeters wide. The bracts are triangular and pointed with a length of about 1.5 millimeters.
The hermaphroditic flowers are radial symmetry and five-fold with a double flower envelope . The chalice has a diameter of 3.2 to 4 millimeters. The five calyx lobes are each 1.5 to 2 millimeters wide, triangular to ovate with a blunt upper end. The cream-colored petals are fused into a 0.8 to 1.3 centimeter long calyx tube. The 2 to 3.5 millimeters long and equally wide calyx lobes overlap slightly to the left. The approximately triangular-shaped and Ahlen arrow-like tapering at its base anthers are 1.2 to 1.3 millimeters long. The ovary is about 1.5 millimeters long and has a conical shape. The ring-shaped nectarium is 0.4 to 0.5 millimeters long. The approximately 5 millimeter long stylus has a membrane-like ring at its base and ends in an approximately 0.4 millimeter long, cylindrical scar .
The fleshy drupes, black when ripe, are almost spherical with a diameter of 1.2 to 1.5 centimeters. Each fruit contains one to three oblong, egg-shaped and flat seeds with slightly wrinkled edges.
Occurrence
Rauvolfia nukuhivensis is endemic only to the island of Nuku Hiva on the Marquesas Islands in the southern Pacific . Several populations are known there, one of which has already died out. The first population on the north coast of Nuku Hiva, between the Haataivea peninsula and the village of Aakapa , in which the type specimen was collected by Forest Buffen Harkness Brown in 1921 , disappeared in the following time and this species was considered to be extinct. It was not until 2002 that Jean-François Butaud found several populations consisting of less than 50 individual plants in the region of the island called Terre Déserte . The area of the populations includes the valleys Haahopu , Haatuatua , Hakaavao , Hakaoa , Motuee , Tapueahu and Uea as well as the plateaus Maauu , Putata , Tohuahee and Vaiteheii . The IUCN data is from 1998 and is considered out of date; there it was rated as “Endangered” = “highly endangered”.
Rauvolfia nukuhivensis thrives at altitudes of 198 to 627 meters. This species grows there in dry forests. Various species of the genera Cerbera , figs ( Ficus ), Maytenus , Phyllanthus , soap trees ( Sapindus ) and Xylosma grow in these forests .
Taxonomy
The first description under the name ( Basionym ) Ochrosia nukuhivensis was made in 1972 by Francis Raymond Fosberg and Marie-Hélène Sachet in Micronesica , Volume 8, p. 48. The new combination to Rauvolfia nukuhivensis (Fosberg & Sachet) Lorence & Butaud was made in 2011 by David H. Lorence and Jean-François Butaud published in PhytoKeys .
literature
- David H. Lorence, Jean-François Butaud: A reassessment of Marquesan Ochrosia and Rauvolfia (Apocynaceae) with two new combinations . In: PhytoKeys . No. 4 , 2011, ISSN 1314-2003 , p. 95-107 , doi : 10.3897 / phytokeys.4.1599 .
Individual evidence
- ↑ a b c Rauvolfia nukuhivensis in the endangered Red List species the IUCN 2015 Posted by: J. Florence, 1998. Accessed June 19, 2016th
- ↑ a b c d e f g David H. Lorence, Jean-François Butaud: A reassessment of Marquesan Ochrosia and Rauvolfia (Apocynaceae) with two new combinations . In: PhytoKeys . No. 4 , 2011, ISSN 1314-2003 , p. 95-107 , doi : 10.3897 / phytokeys.4.1599 .
- ^ Rafaël Govaerts: Rauvolfia nukuhivensis. In: World Checklist of Selected Plant Families. WCSP, accessed June 19, 2016 .
