Utricularia humboldtii
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Utricularia humboldtii , illustration |
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Utricularia humboldtii is a carnivorous plant from the genus of the water tubes in the section Orchidioides . It occurs in parts of Brazil , Guyana and Venezuela and lives terrestrial, aquatic and epiphytes .
description
Stolons
In the substrate, the plant forms fleshy stolons that are a few to twenty centimeters long and two to three millimeters thick, which are often dichotomously branched and whose extreme ends are only a few millimeters long and 0.1 to 0.2 millimeters thick, but occasionally also leaf-like flattened, then up to two inches long and one to three millimeters wide. Stolons that grow out of the substrate, so-called "air shoots", are stiff, up to sixty centimeters long and can reach a thickness of up to two millimeters. The plants can use this to “shimmy” from one location to the next.
leaves
Utricularia humboldtii has only a few leaves. Up to eight inches long, upright, rigid leaf stems are up to nine inches long and nineteen centimeters wide, wedge-shaped to inversely egg-shaped, brittle, thick, leathery leaf blades . These are extremely variable in shape and size.
Falling
The short-stalked traps of Utricularia humboldtii emanating from the stolons are dimorphic : the more numerous small traps are 1 to 1.5 millimeters long, the opening is directed downwards, at their tip there are two elongated appendages. The rather rarely occurring large traps reach a length of up to 1.2 centimeters (see picture) and are therefore the largest of the genus, here the opening points away from the axis and appendages are absent.
blossoms
The flower of Utricularia humboldtii is also considered to be the largest of the genus. The upright, little or unbranched inflorescence can reach a height of up to 130 centimeters, the stem is hairless and two to five millimeters thick. On the flower stem, close to the base, there are a few, two to four millimeters long, oblong-delta-shaped lower leaves , as well as ovoid to delta-shaped, oblong, five to seven millimeters long stipules ; the bracts are elongated and significantly shorter than the bracts .
In a loose cluster there are five to sixteen individual flowers at a distance of one to four centimeters on upward-pointing, flattened, one to two centimeters long pedicels . The elongated egg-shaped sepals are up to 2.5 centimeters long , the blue-purple petals five to seven centimeters long. The upper lip is egg-shaped and rounded at the top. It is only slightly larger than the sepals and has a clearly protruding "embossing" from the base. The up to ten centimeters wide, transversely elliptical lower lip has a sap mark consisting of two yellow lines on the heavily swollen base . The pointed spur running under the lower lip protrudes slightly from under it.
The curved stamens are about five millimeters long, the ovary is ovoid, the pen very short. The scar is also split into an upper and lower lip; the upper lip is elongated, round and considerably smaller than the semicircular lower lip.
Fruits and seeds
After fertilization, the plant forms an egg-shaped, nodding capsule up to two centimeters long with solid walls, which opens through a single long gap. The capsule contains numerous flat, winged seeds in the form of scales, which are up to 2.5 millimeters long, the skin is extremely thin and are thus spread by the wind ( anemochory ). Inside, through the transparent skin on the embryo , the leaf systems that already contain chlorophyll are clearly visible. The seeds germinate within minutes of touching the water, break through the seed skin after a few hours and, if possible, anchor themselves immediately in the substrate in order to prevent them from being washed away later by heavy rains.
Distribution and habitat
Utricularia humboldtii is found in Guyana , Venezuela and northern Brazil in partially shaded to full sun locations, preferably at altitudes of 1200 to 2500 m, especially on Tepuis , but occasionally also in savannas, where it descends to up to 300 m. As an epiphyte it colonizes the forks of trees, the leaf axils of Orectanthe species, the funnels of marsh jugs ( Heliamphora ) and the funnels of Brocchinia tatei , Brocchinia micrantha and Brocchinia reducta . In the latter case, the unique case occurs that one carnivorous plant also represents the habitat of another carnivorous plant . However, it also thrives subaquatically in shallow waters or terrestrially on wet rock or in very wet soil (more often in savannas and clearings in the bush).
Systematics and botanical history
Utricularia humboldtii was first described by Robert Schomburgk in 1841 ; the epithet honors Alexander von Humboldt . However, it was already known to the local Arawak , which they called Iperua ("beautiful flower"), the name was used by Peter Taylor in 1986 as the name donor in the first description of the section, to which he assigned Utricularia humboldtii . However, molecular genetic studies in 2005 unequivocally confirmed that Utricularia humboldtii belonged to the Orchidioides section .
literature
- Peter Taylor: The Genus Utricularia. A Taxonomic Monograph (= Kew Bulletin. Additional Series. 14). Royal Botanic Gardens - Kew, London 1989, ISBN 0-947643-72-9 .
- Wilhelm Barthlott , Stefan Porembski, Rüdiger Seine, Inge Theisen: Carnivores. Biology and culture of carnivorous plants. Ulmer, Stuttgart 2004, ISBN 3-8001-4144-2 .
- Entry on www.fleischfressendepflanzen.de
Individual evidence
- ↑ See message here. ( Memento of March 13, 2005 in the Internet Archive ) (Portuguese)
- ↑ See message here. ( Memento of March 13, 2005 in the Internet Archive ) (Portuguese)
- ↑ Kai Müller, Thomas Borsch: Phylogenetics of Utricularia (Lentibulariaceae) and molecular evolution of the trnK intron in a lineage with high substitutional rates. In: Plant Systematics and Evolution. Vol. 250, No. 1, 2005, ISSN 0378-2697 , pp. 39-67, doi : 10.1007 / s00606-004-0224-1 , based on: Kai F. Müller, Thomas Borsch, Laurent Legendre, Stefan Porembski, Wilhelm Barthlott : Recent Progress in Understanding the Evolution of Carnivorous Lentibulariaceae (Lamiales). In: Plant Biology. Vol. 8, No. 6, 2006, ISSN 0894-4563 , pp. 748-757, doi : 10.1055 / s-2006-924706 .
