Cypripedioideae
| Cypripedioideae | ||||||||||||
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Yellow lady's slipper ( Cypripedium calceolus ) |
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| Scientific name | ||||||||||||
| Cypripedioideae | ||||||||||||
| Lindl. |
The Cypripedioideae are a subfamily of the family of orchids (Orchidaceae). With around 120 species in five genera , it is one of the smaller of the five subfamilies of this plant family.
features
All representatives of the Cypripedioideae are perennial, herbaceous plants. The fleshy roots sometimes have velamen . The leaves are arranged in a spiral or two lines, the shoot is slender or compressed. In the bud, the leaves are rolled and the leaf blade is plicate (folded) or the leaves are folded in the bud, smooth and leathery. There is no dividing tissue between leaf and shoot.
The inflorescences of the Cypripedioideae are terminal and mostly unbranched. The flowers are spirally or two-lined on the stem, they are resupinated . The petals are in two threefold circles, usually two petals of the outer circle are completely fused. The labellum forms a sack-like structure. The ovary is subordinate and one-chamber or three-chamber. Two fertile stamens , a Staminodium and the stylus are fused to form a complex structure. The style is short and thick, the scar large and convex, the central scar lobe larger than the two lateral ones. The two lateral stamens are fertile, the pollen grains are stuck together to form a paste or, in some Phragmipedium species, formed into connected pollinia . The middle, sterile stamen is widened like a shield. The fruits are mostly capsule fruits , with Selenipedium they are berry-like . They contain numerous flattened seeds, about a millimeter long and 0.1 millimeter wide. The seeds of Selenipedium are differently lens-shaped and provided with a hard seed coat.
The chromosome numbers vary within the subfamily over a wide range from 2n = 20 in Cypripedium to 26 to 44 chromosomes in Paphiopedilum . The chromosomes are quite large.
The species in this subfamily form fall flowers, where access for insects into the sac-like lip from the front is fairly easy. The interior is designed in such a way that the insects climb past the stigma and stamens out of the flower and pollinate the flower in the process.
distribution
The species of the Cypripedioideae can be found in the north of South America and in Central America ( Mexipedium , Phragmipedium , Selenipedium ), circumboreal in North America, Europe, Africa (Algeria) and in northern Asia ( Cypripedium ) as well as in subtropical and tropical Southeast Asia ( Paphiopedilum ). They do not occur in Australia or Africa. The spread could have originated from an origin in Central America.
Systematics
The association of the five genres has long been undisputed. Their differing number of fertile stamens (two versus one in other orchids) led to the suggestion that they should be considered as a separate Cypripediaceae family. Molecular genetic studies support the incorporation into the Orchidaceae and confirm the relationship of the five genera. A position as sister taxon to all other orchids with the exception of the Apostasioideae is being discussed.
The genera belong here:
- Selenipedium Rchb.f.
- Cypripedium L.
- Mexipedium V.A.Albert & MWChase , with the only species Mexipedium xerophyticum (Soto Arenas, Salazar & Hágsater) VAAlbert & MWChase .
- Phragmipedium Rolfe
- Paphiopedilum Pfitzer .
supporting documents
literature
- AV Cox, AM Pridgeon, VA Albert, MW Chase (1997): Phylogenetics of the slipper orchids (Cypripedioideae, Orchidaceae): nuclear rDNA ITS sequences . Pl. Syst. Evol. 208: 197-223. Online, accessed October 17, 2007
- Robert L. Dressler (1993): Phylogeny and Classification of the Orchid Family . P. 85ff. Cambridge University Press, ISBN 0-521-45058-6
- KM Cameron et al. (1999): A phylogenetic analysis of the Orchidaceae: evidence from rbcL nucleotide sequences. American Journal of Botany 86: 208-224. Online, accessed October 17, 2007
Individual evidence
- ↑ Decouverte de Cypripedium calceolus (Orchidaceae) au Djurdjura (Algérie), nouvelle pour l'Afrique du Nord . In: Flora Mediterranea . tape 29 , 2019, doi : 10.7320 / FlMedit29.207 ( herbmedit.org [PDF; accessed June 1, 2020]).
