Thismiaceae
| Thismiaceae | ||||||||||||
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Thismia rodwayi |
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| Scientific name | ||||||||||||
| Thismiaceae | ||||||||||||
| J. Agardh |
The Thismiaceae are a family of plants from the order of the yam-like (Dioscoreales) within the monocot plants . They are mycotrophic and chlorophyllless plants.
description
Habit and leaves
All species in the family are mycotrophic and chlorophyllless , perennial herbaceous plants . They form branched, coral-shaped rhizomes as persistence organs. The opposite, alternate and two-line arranged leaves are parallel-veined, membranous, simple, small and sessile, or reduced to scales, with smooth leaf margins. The stomata are anomocytic.
Inflorescences and flowers
The flowers stand alone or in racemose inflorescences with bracts together. The radial symmetrical to zygomorphic flowers are threefold and hermaphrodite. There are two circles with three bracts each, they are fused together in the shape of a bell or urn. In many species the inner and outer bracts are very different. There are one (only with Oxygyne ) or two circles with three stamens ; they are free to each other but fused with the bloom cladding; they are bent inwards. In Haplothismia and Oxygyne the stamens are broadened at the base; in the other genera the stamens are either reduced or specialized. The pollen grains have an aperture. Three carpels are one under constant ovary fused with 50 to 100 anatrope ovules . The stylus, which is often short, ends in a three-lobed scar.
Fruits and seeds
The thick-walled capsule fruits contain 50 to 150 seeds and opens at their tip. The tiny seeds have no endosperm and the embryo is only rudimentary when the seeds are mature .
Ingredients and chromosomes
There are calcium oxalate crystals embedded as Rhaphide.
The chromosomes are 1 to 4 µm long. The chromosomes are n = 6-9.
Systematics and distribution
The distribution Thismiaceae is holartic , palaeotropic , neotropic , Australian and Antarctic . It is found mainly in Southeast Asia, Africa, America (especially Brazil), Australia and New Zealand. The areas of the genera are also disjoint . They mostly thrive in tropical areas, but there are also some species in warm temperate zones, for example in Japan.
The family name was first published in 1858 by Jacob Georg Agardh in Theoria Systematis Plantarum , 99. The type genus is Thismia Griff.
According to molecular genetic studies, the taxa of the family are no longer included in the tribe Thismieae within the Burmanniaceae family , sister group of the family are the Taccaceae . The family consists of five genera with about 32 to 50 species:
- Afrothismia ( Engl. ) Schltr. : With around nine species in the tropical rainforests of Africa .
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Haplothismia Airy Shaw : With only one species:
- Haplothismia exannulata Airy Shaw in the Western Ghats of India.
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Oxygyne Schltr. : With only one type:
- Oxygyne triandra Schltr. : It used to thrive in the tropical rainforest of the Cameroon Mountain in West Africa . Three more species of this genus from Japan are now in the genus Saionia Hatus. and thus placed in the Burmanniaceae family. The genus Saionia was first described in 2015.
- Thismia handle. : With about 35 species. They mostly thrive in the rainforests of Asia and South America , a few species are also found in more temperate areas in Australia , New Zealand , Japan and the mid-west of the USA .
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Tiputinia P.E.Berry & CLWoodw. : With only one type:
- Tiputinia foetida P.E.Berry & CLWoodw. in the Amazon region of Ecuador .
swell
- Description of Thismiaceae on the AP website. (Section description and systematics)
- The Thismiaceae family at DELTA. (English)
- Vincent Merckx, Peter Schols, Hiltje Maas-van de Kamer, Paul Maas, Suzy Huysmans & Erik Smets: Phylogeny and evolution of Burmanniaceae (Dioscoreales) based on nuclear and mitochondrial data , in American Journal of Botany, 2006, 93, p. 1684 -1698: Online.
- Erik Vincent Merckx, Freek Bakker, Suzy Huysmans & Erik Smets: Bias and conflict in phylogenetic inference of myco-heterotrophic plants: a case study in Thismiaceae , in Cladistics , Volume 25, Number 1, February 2009, pp. 64-77.
- Vincent Merckx, Martin I. Bidartondo & Nicole A. Hynson: Myco-heterotrophy: when fungi host plants , in Annals of Botany , 2009, ISSN 1095-8290 : PDF-Online.
Individual evidence
- ↑ See also the entry on the Thismiaceae on the website of the Angiosperm Phylogeny Group
- ↑ Rafaël Govaerts (Ed.): Saionia - World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew. Last accessed on January 6, 2017.
- ↑ Tetsukazu Yahara & Hirokazu Tsukaya: Oxygyne yamashitae, a New Species of Thismiaceae from Yaku Island, Japan , in Acta Phytotax. Geobot. 59 (2), 2008, pp. 97-104, ISSN 1346-7565 : PDF-Online. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
