Ochrosia brownii
| Ochrosia brownii | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Branch with open and closed flowers of Ochrosia brownii |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Ochrosia brownii | ||||||||||||
| ( Fosberg & Sachet ) Lorence & Butaud |
Ochrosia brownii , Syn. : Neisosperma brownii is a plant species from the subfamily of rauvolfioideae in the family of Hundsgiftgewächse (Apocynaceae). It is endemic to the Marquesas Islands in the southern Pacific. It was considered to be extinct from 1998 until it was found again in 2003. The IUCN still lists Ochrosia brownii as extinct.
description
Vegetative characteristics
Ochrosia brownii grows as a tree that can reach heights of up to 13 meters and a diameter of up to 24 centimeters at chest height . The bark of the branches is smooth. The deciduous branches are cylindrical with a diameter of 4 to 4.5 millimeters and the older, leafless branches are 6 to 7 millimeters thick. The milky juice is white.
The leaves, which are arranged opposite to each other on short branches and alternate on longer branches, are divided into a petiole and a leaf blade. On the leaf axis there are 1 to 1.5 millimeters long, dark brown hairs which secrete a pale yellow resin . The petiole is 1.7 to 3.3 inches long and 1.7 to 2 millimeters thick. The simple, bald leaf blade is 9.4 to 16.5 centimeters long and 3.2 to 6.4 centimeters wide and is obovate to elliptical. The base of the spreader tapers to a point, the tip of the spreader is pointed and the edge of the spreader is rolled down. The top of the leaf blade is glossy green to yellow-green in color, while the underside is glossy pale green. From each side of the leaf median nerve, 15 to 20 secondary nerves branch off .
Generative characteristics
At the end of an inflorescence stem there are trichotomous, zymous inflorescences , which are 7 to 12 centimeters long. At the tip of the inflorescence, two bare stems with 12 to 18 individual flowers each branch off. Small, scale-like bracts are found in the inflorescence axes .
The hermaphroditic flowers are five-fold with a double flower envelope and are 1.5 to 4 millimeters long together with their flower stalk. The five blunt to rounded sepals are about 2 millimeters long and about 2.5 millimeters wide. The five white and pleasantly scented petals are fused with one another. With a length of 6 to 7 millimeters and a diameter of about 3 millimeters, the corolla tube ends in five corolla lobes. The crown lobes are 6 to 7 millimeters long and 2 to 25 millimeters wide and have a rounded upper end. The two free carpels are conical in shape with a length of 0.7 to 0.8 millimeters. The approximately 0.8 millimeter long, thread-like stylus has a green ring at its base and a 0.7 to 0.8 millimeter long, egg-shaped head, which has a tuft of hair at its tip. The bilobed and about 0.3 millimeter large nectarium is covered with the carpels .
There are per flower two fleshy, orange to maturity drupes formed which are shaped ellipsoid with a length from 3.7 to 5.3 centimeters and a diameter of 2.5 to 3.7 centimeters. The mesocarp, which is also orange and around 5 millimeters thick, envelops the fibrous outside and woody endocarp inside . The endocarp is 3.1 to 4.8 inches long and 1.9 to 3.3 inches thick. The fibers on the endocarp can be up to 1.5 millimeters in diameter. Each fruit contains two ellipsoidal seeds that are about 2.5 inches long, 2.3 to 2.6 inches wide, and about 0.4 inches thick.
distribution
The natural range of Ochrosia brownii is on the Marquesas Islands in the southern Pacific . It only includes the island of Nuku Hiva , of which two populations are known so far , one of which has already died out. The first population on the Toovii Plateau, in which the type specimen was collected by Forest Buffen Harkness Brown in 1921 , disappeared in the following time and the species was considered extinct. Was only in 2003 Jean-François Butaud on the southeast of the Toovii plateau located Vaioa -Plateau, near Matahamo another, consisting of a full-grown tree and several seedlings population.
Ochrosia brownii thrives at altitudes of 730 to 900 meters. This species grows there in evergreen, moist forests. Asplenium australasicum , Histiopteris incisa and Microsorum grossum as well as various types of hibiscus ( Hibiscus ), Ixora , ironwoods ( Metrosideros ), screw trees ( Pandanus ), Phyllanthus , Premna , Wikstroemia and Xylosma grow in the forests .
Taxonomy
It was first described as Neisosperma brownii in 1972 by Francis Raymond Fosberg and Marie-Hélène Sachet in Micronesica . David H. Lorence and Jean-François Butaud transferred this species as Ochrosia brownii in PhytoKeys to the genus Ochrosia in 2011 .
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 .
Web links
Individual evidence
- ↑ Ochrosia brownii in the endangered Red List species the IUCN 1998 Posted by: J. Florence, 1998. Accessed April 24, 2020th
- ↑ 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 .
- ↑ Ochrosia brownii. In: The International Plant Names Index. www.ipni.org, accessed May 30, 2016 (English).