Apostasia wallichii
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Apostasia wallichii , illustration |
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Apostasia wallichii is a kind of the genus Apostasia and thus belongs to the family of orchid (Orchidaceae). The herbaceous plants, which can be up to one meter in size, inhabit a large area in tropical Southeast Asia.
description
Apostasia wallichii forms a rhizome about 2 to 3.5 millimeters in diameter, it is surrounded by dry, 2 to 10 millimeter long lower leaves. The roots arise not only along the rhizome, but also above ground in the area of the lower leaves. They are quite variable in diameter, from 0.5 to 5 millimeters.
The rising, unbranched shoots carry the leaves in a loose rosette. The leaves are narrowly lanceolate, they measure about 10 to 50 centimeters long and 0.3 to 2 centimeters wide. The leaf base is wedge-shaped in a 1 to 4 centimeter long petiole, which surrounds the shoot and completely covers it. The leaf blade contains 15 to 60 longitudinal veins. At the tip of the leaf, the leaf margins have grown together to form a thin, pointed tube up to 2 centimeters long. The leaf margin can be very finely toothed and glandular.
The inflorescence appears terminal, usually it is bent over to drooping. In addition to the main axis, there are usually one to six minor axes, each with about five to 20 flowers . These are yellow, rarely whitish in color and measure about one to two centimeters. Sepals and petals hardly differ, they are each 1 millimeter wide and 4 to 7 millimeters long, plus a tip about 1 millimeter long. The lip can hardly be distinguished from the other petals, it becomes a little wider. The column arises from the stamens and styles that have grown together on the ground . It can be straight or strongly curved. There are two fertile stamens and a sterile staminodium . Usually the stylus protrudes over the stamens, at the end it has the two or three lobed stigma . The resulting capsule fruit measures 12 to 25 millimeters in length and 1.5 to 2 millimeters in diameter.
The "Flora of China" specifies August as the flowering time, while de Vogel observes a year-round flowering time over the large distribution area.
Also due to the large distribution area, the characteristics vary. The plants are smaller on the northern edge of the area. Specimens found on the Ryūkyū Islands measure only 5 to 15 centimeters and are also regarded as a separate species Apostasia nipponica .
Occurrence
Apostasia wallichii is widespread in tropical Southeast Asia. The northern limit of distribution runs from northeast India through southern China. A disjoint, even further north is located on the Japanese Ryukyu Islands. To the southeast, the area stretches across back India , Indonesia, the Philippines to New Guinea and northeast Australia. An area in Sri Lanka is also disjoint. Apostasia wallichii occurs at altitudes of 250 to 1200 meters, exceptionally also at lower altitudes or at altitudes up to 1700 meters.
ecology
The locations are mostly in the shade of evergreen, moist forests, sometimes on the edge of streams.
Apostasia wallichii forms a mycorrhiza with fungi from the genera Ceratobasidium and Botryobasidium .
Systematics and botanical history
Apostasia wallichii was first described by Robert Brown in 1830 . The name wallichii honors Nathaniel Wallich . There are a number of synonyms due to the variability of the characteristics.
Within the genus Apostasia de Vogel places Apostasia wallichii in the Apostasia section ; In contrast to the Adactylus section, these plants have a staminodium. Apostasia nipponica was described in 1930 by Genkei Masamune and in 1963 put by the same author as a subspecies or variety of Apostasia wallichii . During de Vogel Apostasia nipponica was still considered in his revision of the genus in 1969 as a separate species, the "World Checklist of selected plant families" assigns the Kew Gardens Apostasia nipponica only as a synonym for Apostasia wallichii switched Recent studies of DNA on the other hand see Apostasia wallichii as more closely related to Apostasia odorata than to the plants from Japan.
use
De Vogel reports its use as a medicine for diabetes in Malaysia.
supporting documents
The information in this article comes from:
- Chen Xinqi, Stephan W. Gale, Phillip Cribb : Apostasia wallichii . In: Wu Zhengyi, Peter H. Raven (Ed.): Flora of China . tape 25 : Orchidaceae . Missouri Botanical Garden Press, St. Louis 2009, ISBN 978-1-930723-90-0 , pp. 20 ( efloras.org ).
- EF de Vogel: Monograph of the Tribe Apostasieae (Orchidaceae) . In: Blumea . tape 17 , no. 2 , 1969, p. 313-350 .
Individual evidence
- ↑ a b Tomohisa Yukawa, Yuki Ogura-Tsujita, Richard P. Shefferson, Jun Yokoyama: Mycorrhizal diversity in Apostasia (Orchidaceae) indicates the origin and evolution of orchid mycorrhiza . In: American Journal of Botany . tape 96 , no. 11 , 2009, p. 1997-2009 , doi : 10.3732 / ajb.0900101 .
- ^ R. Brown: Apostasia . In: N. Wallich (Ed.): Plantae Asiaticae rariores, or, Descriptions and figures of a select number of unpublished East Indian plants . tape 1 , 1830, p. 75 ( botanicus.org ).
- ↑ Rafaël Govaerts (ed.): Apostasia nipponica. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew .
- ↑ A. Kocyan, Y.-L. Qiu, PK Endress, E. Conti: A phylogenetic analysis of Apostasioideae (Orchidaceae) based on ITS, trnL-F and matK sequences . In: Plant systematics and Evolution . tape 247 , 2004, pp. 203-213 , doi : 10.1007 / s00606-004-0133-3 .
