Voyria tenella
| Voyria tenella | ||||||||||||
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Voyria tenella , Costa Rica |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Voyria tenella | ||||||||||||
| Guilding ex Hook. |
Voyria tenella is a leaf green loose, parasitically living on fungi species from the family of the Gentian family (Gentianaceae), which is native to the Caribbean, Central and South America.
features
Voyria tenella is a one-year , herbaceous plant that grows in dense clusters. It reaches heights of growth of up to 20 centimeters. It no longer carries out photosynthesis , but lives parasitically on fungi and is completely dependent on them for its nutrition. The vascular bundle system consists of only four isolated, concentric vascular bundles with inner xylem.
The white to cream-colored stems are simple, the few internodes up to 5 centimeters long. The bulbous, slightly fleshy roots form dense, morning star-shaped clumps. They are white, narrow, obovate and taper towards the extreme end. They reach a length of 1 to 10 millimeters, have a diameter of 0.4 to 1 millimeter and are densely covered with hair around 0.01 millimeters long. The leaves are white to yellow, triangular to narrow triangular and fused together at the base. They are 2 to 5 millimeters long and 1 to 1.5 millimeters wide.
The species blooms all year round, but particularly frequently in August. The flowers are five-fold, weakly scented and nodding as buds, single flowers erect to flower, bracts are missing. The flower stem is 10 to 50 millimeters long. The orange to yellow, rarely white calyx is tubular to bell-shaped and reaches a length of 2.5 to 4 millimeters. The calyx tube and calyx lobes are of the same length, namely 1 to 2 millimeters. The calyx lobes are narrowly ovate to narrowly triangular, 0.3 to 0.5 millimeters wide and blunt to slightly pointed at the extreme end. Cup scales are clearly recognizable.
The salver-plate-shaped crown is 9 to 22 millimeters long and is obsolete except for the base of the corolla tube. The white to orange corolla tube reaches a length of 7 to 15 millimeters, its slightly widened throat is yellow to pale orange. The narrowly ovate to narrow obovate corolla lobes are 2 to 7 millimeters long and 0.5 to 2.5 millimeters wide, blunt at the extreme end. They are blue, occasionally purple, rarely white.
The stamens set 2 to 3 millimeters below the throat. The anthers are approximately sessile and 0.5 to 1 millimeter long and dorsifix. The counter taper towards the base, at the outer end they are rounded to blunt. The ovaries are thread-shaped, 3 to 5 millimeters long and 1 to 2 millimeters wide, at the base they have two club-shaped stalked glands, the stalk is 1 to 2 millimeters long. The 2 to 4 millimeter long stylus has a head-shaped scar .
The fruit is an elliptical to round capsule that is 4 to 7 millimeters long and 2 to 4 millimeters wide. The thread-like seeds are 0.035 to 0.06 millimeters wide and 0.55 to 0.78 millimeters long, of which only 0.14 to 0.19 millimeters represent the actual seed body. Its surface is more or less wetted. The embryo consists of only three or four cells.
The basic chromosome number is n = 18.
Life cycle
The species is annual, the entire life cycle of the plants is completed within just two months. The seedling is a piece of root only 2 millimeters long, from which the morning star-shaped root system is formed. Only then do the shoot axes break through the earth's surface. The flowers, which emerge from the three to four shoots, which often do not bloom at the same time, last only a few days, they are mainly visited by flies ( Brachycera ), but self-pollination cannot be ruled out. The capsules ripen within four to five days and then tear open from below, turning the ovules with the adhering seeds outwards. Occasionally, further root stars form secondary, but they do not represent stages of persistence.
Because of the shape of the seeds, it was long assumed that they were spread by the wind. Later investigations indicated, however, that the species' habitats are windless and that self-dispersal due to the overturning of the dried flower stalks may be more likely. However, there are even stronger indications of the spreading by ants; observations have shown an at least optional myrmecochory .
distribution
Voyria tenella is a neotropically distributed species and is found in the Caribbean ( Hispaniola , Montserrat , Guadeloupe , St. Vincent ) and Central America (Mexico to Panama) to South America (Colombia, Venezuela, Suriname, Trinidad, Guyana, Ecuador, Peru, Brazil, Bolivia). There it occurs at altitudes from 0 to 1400, rarely 1700 meters in forests, often with shallow roots in deciduous humus, occasionally on decaying tree trunks.
Taxonomy
The species was described in 1829 by William Jackson Hooker under the name Vohiria tenella . This first description was based on plants that the theologian and naturalist Lansdown Guilding had collected on the island of St. Vincent . Hooker took the name from a Guilding manuscript, but the illustration attached to the first description shows the name V. tenera . The specific epithet refers to the delicate appearance of the plant.
proof
- ^ A b c Stephan Imhof, Hans Christian Weber, Luis Diego Gómez: A contribution to the biology of Voyria tenella Hook. and Voyria truncata (Standley) Standley & Steyermark (Gentianaceae). In: Contributions to the Biology of Plants, 68: 113-123, 1994
- ↑ a b c d e f g h P. JM Maas, P. Ruyters: Voyria and Voyriella (Gentianaceae) , Flora Neotropica, Monogr. 41: 73-77, 1986
- ↑ Hooker WJ 1829 ("1830"): Voyria tenella. Bot. Misc. 1: 47, Tab.XXV B. - Online - Figure
- ↑ Helmut Genaust: Etymological dictionary of botanical plant names. 3rd, completely revised and expanded edition. Birkhäuser, Basel / Boston / Berlin 1996, ISBN 3-7643-2390-6 (reprint ISBN 3-937872-16-7 ).
