Bathiorhamnus
| Bathiorhamnus | ||||||||||||
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| Scientific name | ||||||||||||
| Bathiorhamnus | ||||||||||||
| Capuron |
Bathiorhamnus is a genus from the family of the Buckthorn family (Rhamnaceae). It includes seven types of small trees , all of which are endemic to Madagascar .
description
Vegetative characteristics
The Bathiorhamnus species are small trees, usually up to about 15 m high. Bathiorhamnus macrocarpus can reach a height of up to 25 m. Most of the species are evergreen , only Bathiorhamnus cryptophorus and Bathiorhamnus capuronii shed their leaves in the dry season. The greyish or brownish, mostly slender, leafy branches are hairy or hairless and in some species richly covered with lenticels . The leaves are alternate . The yellowish or whitish, early falling stipules are pointed-triangular, downy hairy and 1–5 mm long, depending on the species. The bald, downy-haired or balding, usually blackish drying leaf stalks are up to 2 cm long. The simple and undivided leaf blades are leathery in most species, herbaceous in the two deciduous species. They are up to 11 cm long and up to 5 cm wide and have a rounded, egg-shaped, elliptical, broadly lanceolate or obverse-shaped shape. The spreads are usually rounded at the base, less often narrowed, pointed at the front, blunt or truncated, finely notched to entire at the edge and in some species have a rolled edge. They are three-nerved, with the arched lateral nerves branching off from the midrib at the base of the blade or, more rarely, slightly above it, and reuniting with it at the tip. The main nerves are somewhat depressed at the top and protrude at the bottom. In Bathiorhamnus capuronii and Bathiorhamnus cryptophorus , domatia are present in the armpits of the two lateral nerves , which can be seen as hairy humps on the upper side of the blade . The blades, mostly of the same color on both sides, but lighter on the underside in Bathiorhamnus capuronii, are mostly bare. In Bathiorhamnus cryptophorus they are quite densely hairy on both sides, in Bathiorhamnus capuronii they are rough-haired on the underside of the main nerves.
Generative characteristics
The flowers stand individually in the axils of the leaves or in axillary, sedentary or, more rarely, short-stalked, little-flowered cymes or clusters. The tiny bracts of the flowers fall off early. The thin, downy-haired pedicels are 2–10 mm long.
The hermaphrodite , radially symmetrical , five-fold flowers are mostly yellowish and have a diameter of 4 to 9 mm. Bathiorhamnus capuronii has the smallest flowers, Bathiorhamnus macrocarpus the largest . The five triangular sepals up to 4 mm long, flap in the bud , are usually short downy-haired on the outside and keeled to the tip on the inside. The five hood-shaped petals up to 2 mm long , only thread -shaped in Bathiorhamnus vohemarensis , are narrowed into a nail of different lengths. They fall off quickly. The five stamens are in front of the petals and are fully developed longer than these. They consist of stamens widened at the base and ovoid, 0.5–1.5 mm long anthers. In the center of the flower, surrounded by the stamens, is a thick, pentagonal, cut off at the base of the sepals nectar discus , in which the half under constant, dreifächerige ovary is sunk. The short, conical stylus is deeply Three column and 1-2 mm long.
The fruits are spherical or very weakly three-lobed stone fruits with three or, as a result of reduction, also fewer stone pits, which do not fall apart when ripe. The flower base is retained on the fruit, and sometimes the calyx in Bathiorhamnus macrocarpus as well. The fruits are 8 to 30 mm in diameter. The exocarp is 0.5–1.5 mm thick in most species and 3 mm thick in Bathiorhamnus macrocarpus . The egg-shaped to spherical stone cores are flattened dorsoventrally and grooved on the outside. The seeds do not contain endosperm . The embryo contains oil.
distribution and habitat
Bathiorhamnus comprises seven species, all of which are endemic to Madagascar. The most species-rich region is the northern tip of the island, where four species are spatially adjacent.
The populated habitats range from the tropical lowland rainforest on the east coast of the island near Bathiorhamnus macrocarpus to dry forests in the west and north of the island near Bathiorhamnus reticulatus and Bathiorhamnus capuronii to the subarid bushland in the southwest near Bathiorhamnus cryptophorus . Bathiorhamnus louvelii reaches heights of over 1500 m in the highlands in moist mountain forests . Bathiorhamnus vohemarensis inhabits a special location , namely beach forests on sand in the area around Vohémar in the north of the island.
Taxonomy and systematics
Bathiorhamnus was described by René Paul Raymond Capuron in 1966 . At the time of the first description , the genus only contained the type species Bathiorhamnus louvelii with four varieties . This species had previously been listed as Macrorhamnus louvelii H.Perrier . The remaining Macrorhamnus species were transferred to Colubrina on this occasion .
Within the buckthorn family , Bathiorhamnus is the only genus in the Bathiorhamneae tribe . In a phylogenetic analysis based on two regions of the plastid - genome formed Bathiorhamnus a clade with the two neotropical genera Ampelozizyphus and Doerpfeldia . Since these three genera have little morphological similarity and also diverge strongly in molecular biology , each of them is placed in its own tribe. It is assumed that these three genera are remnants of a family group within the buckthorn family, which used to be more diverse and more diverse.
etymology
The first part of the name Bathiorhamnus is a dedication to the French botanist Henri Perrier de la Bâthie , who was the first to describe Macrorhamnus louvelii (= Bathiorhamnus louvelii ), the type species of the genus. The second part of the name refers to Rhamnus , the genus of the buckthorn family that gives it its name.
species
Until 2008, only two species were recognized in the genus Bathiorhamnus , Bathiorhamnus louvelii and Bathiorhamnus cryptophorus, which was described in 1972 . During the last genus revision , the varieties of B. louvelii were raised to species rank and two new species were described in addition to the previously known. The genus thus includes the following seven species:
| Scientific name | distribution |
|---|---|
| Bathiorhamnus capuronii Callm. , Phillipson & Buerki | Western and Northern Madagascar |
| Bathiorhamnus cryptophorus Capuron | South and Southwest Madagascar |
| Bathiorhamnus dentatus (Capuron) Callm., Phillipson & Buerki | Northern Madagascar |
| Bathiorhamnus louvelii ( H.Perrier ) Capuron | eastern and northern Madagascar, up to the highlands |
| Bathiorhamnus macrocarpus (Capuron) Callm., Phillipson & Buerki | East coast of Madagascar |
| Bathiorhamnus reticulatus (Capuron) Callm., Phillipson & Buerki | southern and western Madagascar |
| Bathiorhamnus vohemarensis Callm., Phillipson & Buerki | Northern Madagascar |
Danger
Callmander, et al. (2008) carried out a provisional assessment for all Bathiorhamnus species according to the criteria of the IUCN Red List of Threatened Species . Accordingly, Bathiorhamnus capuronii , Bathiorhamnus dentatus and Bathiorhamnus macrocarpus were classified as “Endangered” (VU), Bathiorhamnus cryptophorus as “Endangered” (EN) and Bathiorhamnus vohemarensis as “ Critically Endangered” (CR). Only Bathiorhamnus louvelii and Bathiorhamnus reticulatus are considered “not endangered” (LC).
annotation
- ↑ In the generic revision by Callmander et al. (2008), p. 153 it is expressly stated that the fruits do not disintegrate. In contrast, Johnston (1971) showed that the fruit of Bathiorhamnus disintegrates into partial fruits like that of Colubrina , but in contrast to Colubrina these do not split any further. - see. MC Johnston: Revision of Colubrina (Rhamnaceae). In: Brittonia. 23, 1971, pp. 2-53. doi: 10.2307 / 2805841
swell
- MW Callmander, PB Phillipson, S. Buerki: Révision du genre Bathiorhamnus Capuron (Rhamnaceae) endémique de Madagascar. In: Adansonia. sér. 3, 30 (1), 2008, pp. 151-170. ( PDF; 2.72 MB ( Memento from May 14, 2013 in the Internet Archive ))
Individual evidence
- ^ R. Capuron: Notes sur quelques Rhamnacées arbustives ou arborescentes de Madagascar. In: Adansonia. ns, 6, 1966, pp. 117-141. quoted by MW Callmander, PB Phillipson, S. Buerki: Révision du genre Bathiorhamnus Capuron (Rhamnaceae) endémique de Madagascar. In: Adansonia. sér. 3, 30 (1), 2008, pp. 151-170.
- ^ A b c MW Callmander, PB Phillipson, S. Buerki: Révision du genre Bathiorhamnus Capuron (Rhamnaceae) endémique de Madagascar. In: Adansonia. sér. 3, 30 (1), 2008, pp. 151-170. ( PDF ( Memento from May 14, 2013 in the Internet Archive ))
- ↑ D. Medan, C. Schirarend: Rhamnaceae. In: K. Kubitzki (Ed.): The families and genera of Vascular Plants. Vol. VI: Flowering Plants: Dicotyledons: Celastrales, Oxalidales, Rosales, Cornales, Ericales. Springer, Berlin / Heidelberg / New York 2004, ISBN 3-540-06512-1 , pp. 320–338.
- ↑ a b J. E. Richardson, MF Fay, QCB Cronk, D. Bowman, MW Chase: A phylogenetic analysis of Rhamnaceae using rbcL and trnL-F plastid DNA sequences. In: American Journal of Botany. 87, 2000, pp. 1309-1324. (Abstract) ( Memento of the original from June 26, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ FA Stafleu, RS Cowan: Taxonomic literature. A selective guide to botanical publications and collections with dates, commentaries and types. Vol. IV: P-Sak. (= Regnum Vegetabile. 110). 2nd Edition. Bohn, Scheltema & Holkema, Utrecht / Antwerp 1983, ISBN 90-313-0549-9 . (on-line)
Web links
- Bathiorhamnus. In: Germplasm Resources Information Network (GRIN). United States Department of Agriculture (USDA), ARS, National Genetic Resources Program, National Germplasm Resources Laboratory, Beltsville, Maryland, accessed October 31, 2012 .