Auxopus
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The genus auxopus from the family of the orchid (Orchidaceae) consists of three types . These plants do not photosynthesize , but live mycoheterotrophically . They occur in tropical Africa and Madagascar.
description
The Auxopus species develop an elongated, fleshy, spindle-shaped, bulbous, thickened rhizome . This is where the yellowish-brown shoots arise . They are covered with a few lower leaves at the base , the leaves on the stem are also greatly reduced. The stem axis continues in a racemose inflorescence . The flowers are crowded in the upper area of the inflorescence axis. They are resupinated , small and brownish in color. The petals are - except for the lip , which is free - grown together at the base and form a tube. The tips of the upper sepal and the petals are bent back and reveal the column . The lateral sepals are fused together up to the tip. The lip is white, wider than the other petals, entire or slightly bilobed. At the base it is briefly fused with the column, there are also two yellow calluses. The column has two appendages (stelidia) at the end. The stamen is bent down in relation to the columnar axis, it contains four pollinia . The glutinous gland ( Viscidium ) is bilobed, after removal a V-shaped incision remains in the rostellum. The flower stalks lengthen significantly until the capsule fruits are ripe .
distribution
The species of the genus Auxopus are widespread in tropical Africa, Madagascar and the Mascarene Islands . The locations are in forests that are always moist to sometimes dry. The plants grow in soils rich in humus.
Systematics and botanical history
The genus Auxopus is counted to the tribe Gastrodieae . Related genera are Didymoplexis and Didymoplexiella .
The genus was described by Rudolf Schlechter in 1905 . The type species is Auxopus kamerunensis . The name auxopus describes the elongated flower stalks. There are four known types:
- Auxopus kamerunensis Schltr. : It occurs in tropical West Africa.
- Auxopus letouzeyi Szlach., Mytnik, Rutk., Jerch. & Baranow : It occurs in Cameroon.
- Auxopus macranthus Summerh. : It occurs from tropical West Africa to Uganda.
- Auxopus madagascariensis Schltr. : It occurs in northwestern Madagascar.
literature
Most of the information in this article comes from:
- Alec M. Pridgeon, Phillip Cribb, Mark W. Chase (Eds.): Genera Orchidacearum. Epidendroideae (Part one) . 2nd Edition. tape 4/1 . Oxford University Press, New York and Oxford 2005, ISBN 0-19-850712-7 , pp. 437-439 .
- L. Börje Segerbäck, Phillip Cribb, CZ Tang: Orchids of Nigeria . CRC Press, 1983, ISBN 978-90-6191-217-0 , pp. 29-30 .
Individual evidence
- ↑ a b c d e Rafaël Govaerts (Ed.): Auxopus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved July 6, 2018.