Drosera leioblastus
| Drosera leioblastus | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Drosera leioblastus | ||||||||||||
| NGMarchant & Lowrie |
Drosera leioblastus is a species of sundew ( Drosera ). This carnivorous plant belongs to the group of so-called dwarf sundews. This endemic occurs only in southwestern Australia.
description
Vegetative characteristics
Drosera leioblastus is a perennial herbaceous plant . It forms a multi-layered, rosette-shaped bud made of leaves with a diameter of about 1.5 centimeters. The stem axis is 1 centimeter long and covered with the withered leaves of the preseason.
The bud of the stipules is ovate, smooth, 6 millimeters long and 4 millimeters in diameter at the base. The stipules themselves are 3.5 millimeters long, 2 millimeters wide, 1 millimeter wide at the base and three-lobed. The middle lobe is entire , the point slightly serrated . The side lobes are similar, but the top outer edge is divided from the tip to form a short fringe.
The leaves are divided into a petiole and a leaf blade. The leaf stalks are 4.5 millimeters long, 0.6 millimeters long at the base and taper to 0.4 millimeters at the leaf blade. Some of them are narrowly elliptical and have a few glands on the underside along the margins near the leaf blade. Otherwise hairless. The leaf blades are circular and 1.7 millimeters in diameter. The longer tentacle glands are on the edge, the shorter ones on the inside. They are bare on the underside.
The formation of brood scales is typical of dwarf sundews : The broad, egg-shaped, 0.6 millimeter thick brood scales are formed in large numbers from late November to early December and are around 1.2 millimeters long and 1 millimeter wide.
Generative characteristics
The flowering period in Australia extends from September to December. The one or two inflorescence shafts are up to 2 centimeters long and completely densely covered with cylindrical glands. The inflorescence is a coil and contains 20 to 30 flowers along one side of the inflorescence axis. The flower stalks are about 0.7 millimeters long.
The hermaphroditic flowers are radial symmetry and five-fold with a double flower envelope . The five sepals are egg-shaped with a length of about 1.5 millimeters and a width of about 1 millimeter . Their lower edges are ganzrandig , the rest and the tips irregularly cut and its surface is covered at the base with some glands. The five white petals are narrowly elliptical with a length of 1.5 to 2 millimeters and a width of 0.4 to 0.5 millimeters.
The five stamens are 1 millimeter long. The stamens and anthers are white, the pollen yellow. The white ovary is about 0.5 millimeters long and 0.5 millimeters in diameter, circular and warty. The three white styluses are half upright and about 0.2 millimeters long. The yellow scars are crescent-shaped with a length of about 0.4 millimeters and a diameter of about 0.1 millimeters at the base and they taper to a point.
The number of chromosomes is 2n = 10.
Distribution, Habitat and Endangerment
Drosera leioblastus occurs only on a small area in the extreme southwest of Australia. It thrives there on sandy soils containing silica , mixed with humus from discarded leaves under and between low heather.
Drosera leioblastus is only known from one location north of Cataby . Extensive clearing has already destroyed most of the former habitat .
Systematics
The first description of Drosera leioblastus done by Neville Graeme Marchant and Allen Lowrie . The specific epithet leiblastus is made up of the ancient Greek words "leios" for smooth and "blasta" for resting bud and refers to the smooth stipple bud.
At first glance, the species Drosera leioblastus corresponds to Drosera paleacea . However, more detailed investigations showed that Drosera leioblastus differs in many ways. A characteristic is that the inflorescence of Drosera leioblastus is densely covered with long cylindrical glands. The second characteristic can be seen in the resting buds of both species: Where Drosera paleacea has wildly fringed stipules , Drosera leioblastus has almost entire lobes.
In 1996 Jan Schlauer presented the taxa Drosera leioblastus , Drosera roseana and Drosera stelliflora as subspecies of Drosera paleacea , Allen Lowrie accepted, however, in addition to Drosera paleacea N.G. Marchant & Lowrie subsp. paleacea only the subspecies:
- Drosera paleacea subsp. trichocaulis (Diels) NGMarchant & Lowrie
literature
- Allen Lowrie: Carnivorous Plants of Australia. Volume 2. University of Western Australia Press, Nedlands 1989, ISBN 0-85564-300-5 , p. 70.
Individual evidence
- ^ Drosera leioblasta at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ↑ Jan Schlauer: A dichotomous key to the genus Drosera L. (Droseraceae). In: Carnivorous Plant Newsletter. Volume 25, 1996, ISSN 0190-9215 , pp. 67-88, ( digital version (PDF; 1 MB) ).
- ↑ Allen Lowrie, John G. Conran: A revision of the Drosera omissa / D. nitidula complex (Droseraceae) from south-west Western Australia. In: Taxon. Volume 56, Number 2, 2007, ISSN 0040-0262 , pp. 533-544, JSTOR 25065808 .