Mentzelioideae
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Smooth-stemmed mentcelia ( Mentzelia laevicaulis ) |
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| Scientific name | ||||||||||||
| Mentzelioideae | ||||||||||||
| ( Rchb. ) Urb. & Gilg |
The Mentzelioideae are a subfamily of the flower nettle family (Loasaceae).
description
The upper leaves are always alternate, those in the lower part of the plant are opposite. They are covered with stinging trichomes , and nettle hairs are occasionally found.
The inflorescences are terminally similar to thyrsen , often without metatopy . The upright flowers are stalked or sessile. In front of each individual flower there are two bractose or frondose prophylls .
The hermaphrodite flowers are usually radial symmetry and five-fold with a double flower envelope . The five sepals are durable. The five petals are mostly ingrown, flat or flat boat-shaped, not nailed, with entire margins, membranous and with more than three main nerves emanating from the base .
The androeceum usually consists of many circles, rarely it is obdiplostemon . If present, the staminodes are corolla-shaped and not overgrown to the base. The stamens are usually thread-like, occasionally widened or forked at the end. The anthers open away from the center of the flower. The ovary contains numerous ovules with parietal placentation .
With the cylindrical capsule fruits , ribs do not protrude and they open at the outer end through three to five fruit valves. The gray or brown seeds are egg-shaped or angular or laterally flattened.
distribution
The subfamily Mentzelioideae is common in the New World. It is found from Canada to Argentina and extends to the Galapagos Islands and the Caribbean Islands. The center of diversity is Mexico and the southwestern United States.
Systematics
The subfamily Mentzelioideae contains three genera with just over a hundred species:
- Mentzelia L .: The 95or sospecies arewidespreadfrom North America through Mexico , Central America and on the Caribbean islands to South America .
- Eucnide Zucc. : About 14 species are distributed from the southern USA over especially Mexico to Guatemala.
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Schismocarpus S.F.Blake : It contains only one species:
- Schismocarpus pachypus S.F.Blake : This endemic occurs only in the Mexican state of Oaxaca .
literature
- Maximilian Weigend: Loasaceae. In: Klaus Kubitzki (Ed.): The Families and Genera of Vascular Plants . Volume 6: Flowering Plants, Dicotyledons: Celastrales, Oxalidales, Rosales, Cornales, Ericales . Springer, Berlin / Heidelberg / New York 2004, ISBN 3-540-06512-1 , pp. 252 (English, limited preview in Google Book search).
Individual evidence
- ↑ a b Larry Hufford: Loasaceae - the same text online as the printed work , In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico , Volume 12 - Magnoliophyta: Vitaceae to Garryaceae , Oxford University Press, New York and Oxford, December 22, 2016, ISBN 978-0-19-064372-0 .