Dictyostega orobanchoides
| Dictyostega orobanchoides | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Flowering diagram Dictyostega |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name of the genus | ||||||||||||
| Dictyostega | ||||||||||||
| Miers | ||||||||||||
| Scientific name of the species | ||||||||||||
| Dictyostega orobanchoides | ||||||||||||
| ( Hook. ) Miers |
Dictyostega orobanchoides is a mykoheterotrophic , leaf-green-free plant species and the only species of its genus fromthe Burmanniaceae family .
description
Dictyostega orobanchoides is an upright and herbaceous species. It reaches heights of between 10 and 48 centimeters. It no longer carries out photosynthesis , but lives parasitically on fungi and is completely dependent on them for its nutrition.
The rhizomes are up to 1 millimeter thick and densely covered with 1.6 to 4 millimeters long, 0.2 to 0.8 millimeters wide and narrow, egg-shaped scale sheets. The scale sheets and their spaces between them are colonized by the hyphae of arbuscular mycorrhizal fungi . The fungus also colonizes the tissue of the leaves, but not that of the actual rhizome. The edges of the rhizome scales or long hairs at their tips may take on the function of the root hairs , which Dictyostega as well as the whole family lack.
The inflorescence axes have a white to reddish tinge, the leaves are narrow-egg-shaped, tapering to a point, 1.2 to 8.5 millimeters long and 0.4 to 2.5 millimeters wide. The bracts are similar, but significantly smaller in all dimensions.
The flowers are white to reddish or pale yellow and up to 8.5 millimeters long. The capsule fruits are broadly elliptical, 3.5 millimeters long, 4 millimeters wide and contain numerous tiny seeds.
distribution
Dictyostega orobanchoides is found from Mexico through Central America to northern South America (Bolivia, Brazil). It grows at altitudes from sea level up to around 2600 meters.
Systematics
One can distinguish three subspecies:
- Dictyostega orobanchoides (Hook.) Miers subsp. orobanchoides : It occurs in tropical America.
- Dictyostega orobanchoides subsp. parviflora (Benth.) Snelders & Maas : It occurs in Trinidad and from Panama to tropical South America.
- Dictyostega orobanchoides subsp. purdieana (Benth.) Snelders & Maas : It occurs from southern Panama to Peru.
literature
- PJM Maas, H. Maas-van de Kamer, J. van Bentham, HCM Snelders, T. Rübsamen: Burmanniaceae , Flora Neotropica, Monogr. 42: 1-189, 1986
- Stephan Imhof: Subterranean structures and mycotrophy of the achlorophyllous Dictyostega orobanchoides (Burmanniaceae) , in: Revista de Biología Tropical, Vol.49, No.1, 2001, online , accessed October 1, 2007
Individual evidence
- ↑ a b c d Rafaël Govaerts (ed.): Dictyostega. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved January 5, 2017.