Geosiris aphylla
| Geosiris aphylla | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Geosiris | ||||||||||||
| Baill. | ||||||||||||
| Scientific name of the species | ||||||||||||
| Geosiris aphylla | ||||||||||||
| Baill. |
Geosiris aphylla is a mykoheterotrophic , leaf-green-free plant species and a species of the genus from the family of the Iris family (Iridaceae).
description
Geosiris aphylla is a small herbaceous plant . It no longer carries out photosynthesis , but lives mykoheterotrophically on arbuscular mycorrhizal fungi , so it is completely dependent on fungi for its nutrition. The rhizome is bulbous, the unbranched or slightly branched stem, like the whole plant, is pale white and reddish to purple. There are only a few, alternating, scale-like leaves that are membranous.
Flowering time is from December to February. The terminal inflorescence is a double screw standing in a spathe from two bracts and is composed of one to eighteen densely packed flowers . Well-grown plants form additional side florets that are formed from the axilla of a bract , opposite to which there is a cover sheet on the axis .
The strongly sweet smelling flowers are hermaphroditic, sessile, actinomorphic and threefold, the short-lived perigone consists of two leaf circles and is spread out horizontally. The bracts are of the same size and shape, obovate to lanceolate, elliptical, fused together in the lower part to form a short corolla tube and colored blue to blue-violet. The three stamens are not fused together, but on the corolla tube. The stamens are short and wide, the elongated anthers point away from the flower center. The stylus is divided into three scar branches. Nothing is known about pollinators, but the color, flower structure and scent indicate insects.
The ovary is inferior, the placentation central angle continuously and contains numerous ovules . The fruit is a capsule and contains numerous, tiny seeds.
distribution
Geosiris aphylla is endemic to the east and north of Madagascar and Sainte Marie . There it can be found from sea level to altitudes of 1900 meters. It colonizes shady locations in forests on humus soils.
Systematics and botanical history
Species and genus were first described by Henri Ernest Baillon in 1895 , the genus name means something like "earth iris", the species epithet refers to the lack of foliage in the plants. Baillon placed it among the irises, a placement that Engler contradicted in his 1897 syllabus by classifying it as a Burmanniaceae . Fredric Jonker rejected this in his revision of the Burmanniaceae, however, since Geosiris "deviates too much to be classified as a Burmanniaceae" and later placed it in a family of its own, the Geosiridaceae.
Later authors ran it either as a separate family or as an iris family, Peter Goldblatt classified it as the latter. These assumptions were confirmed in 1994 by extensive morphological and embryological investigations of Traudel rapeseed .
proof
- T. Rübsamen-Weustenfeld, V. Mukielka & U. Hamann: On the embryology, morphology and systematic position of Geosiris aphylla Baillon (Monocotyledoneae-Geosiridaceae / Iridaceae) In: Bot. Jahrb. Syst. 115. 1994, 475-545
- L. Watson, MJ Dallwitz: The families of flowering plants: descriptions, illustrations, identification, and information retrieval , accessed April 10, 2008, online
Individual evidence
Most of the information in this article has been taken from the sources given under references; the following sources are also cited:
- ↑ a b Peter Goldblatt: Iridaceae , Flore de Madagascar et des Comores Fam. 45 , 1992, pp. 18-21, ISBN 2856541925
- ↑ Collection records at Tropicos.org, Missouri Botanical Garden, accessed April 30, 2008, online
- ↑ ".. is deviating too much to be classified in Burmanniaceae." Fredrik Pieter Jonker: A monograph of the Burmanniaceae , Meded. Bot. Mus. Herb. Rijks Univ. Utrecht 51, 1938, p. 9
