Cranichideae
Cranichideae | ||||||||||||
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![]() Ponthieva maculata |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Cranichideae | ||||||||||||
( Lindl. ) Endl. |
Cranichideae is a tribe from the orchid family (Orchidaceae). It contains around 600 species that are distributed almost worldwide. They are herbaceous , mostly small plants.
features
The Cranichideae have fleshy roots , sometimes thickened to spindle-shaped storage organs, root tubers occur in the subtribe Pterostylidinae . The roots can - depending on the subtribe - be distributed individually on a rhizome or stand together in clusters. The leaves are rolled ( convolut ) in the bud and arranged in a spiral on the shoot.
The inflorescence is a terminal raceme , sometimes reduced to just one flower . The petals of the outer circle are usually similar to one another, the lateral ones can be somewhat asymmetrical or grown together. The lateral petals often adhere to the upper sepal . The shape of the lip is very variable, often it has a depression or a clear spur at the base. The scar is entire, bilobed or consists of two surfaces. The stamen is parallel to the column axis and is connected to it by a short stamen. At this point, a raised edge or a cap often forms around and over the stamen (clinandrium), this tissue arises from the staminodes . The stamen contains a total of two or four pollinia in two chambers . The separating tissue between the stigma and the stamen ( rostellum ) is often drawn out and bears the adhesive disc ( viscidium ) on which the pollinia hang.
distribution
The species of the tribe Cranichideae are distributed worldwide with the exception of deserts and arid regions. The main focus of the distribution are the tropics and subtropics of America and Asia.
Systematics
The tribe Cranichideae is part of the subfamily Orchidoideae . It is sister taxon of the Diurideae . As early as 1840, Lindley summarized the relationship to the type genus Cranichis , it was described as a tribe by Endlicher in 1842.
In 1926, Schlechter presented a subdivision into five subtribes, which Dressler took up in 1993 and added a subtribe. The majority of the species were therefore distributed among the subtribes Cranichidinae , Goodyerinae , Prescottiinae and Spiranthinae ; in addition the Manniellinae and Pachyplectroninae, each containing only one genus .
Since then, recent studies have expanded the scope of the Cranichideae on the one hand, and some groups have been combined on the other. So a close relationship of Prescottiinae and Cranichidinae has been shown, both can be summarized under the latter name. Pachyplectron is closely related to the Goodyerinae and is one of them. The genus Galeottiella , still part of the Spiranthinae at Dressler, can be viewed as a separate subtribe Galeottiellinae. While Dressler lists the genus Pterostylis as a subtribe Pterostylidinae within the Diurideae, Chase counts it to the Cranichideae. A basal taxon within the Cranichideae is the genus Achlydosa ; their relationship to Pterostylis is still unclear.
The subtrata of the tribe Cranichideae:
literature
- Robert L. Dressler: Phylogeny and Classification of the Orchid Family . Cambridge University Press, 1993, ISBN 0-521-45058-6 , pp. 117-123 .
- Alec M. Pridgeon, Phillip Cribb, Mark W. Chase, Finn Rasmussen (Eds.): Genera Orchidacearum. Orchidoideae (Part 2). Vanilloideae . tape 3 . Oxford University Press, New York and Oxford 2003, ISBN 0-19-850711-9 , pp. 21-23 .
- Gerardo A. Salazar, Mark W. Chase, Miguel A. Soto Arenas, Martin Ingrouille: Phylogenetics of Cranichideae with emphasis on Spiranthinae (Orchidaceae, Orchidoideae): evidence from plastid and nuclear DNA sequences . In: American Journal of Botany . tape 90 , no. 5 , 2003, p. 777-795 .