Drosera platystigma
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Drosera platystigma , habitus |
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| Drosera platystigma | ||||||||||||
| Clay. |
Drosera platystigma is a carnivorous plant belonging to the genus sundew ( Drosera ). It belongs to the group of so-called dwarf sundews and is native to southwestern Australia.
description
Drosera platystigma is a perennial herbaceous plant . This forms a flat, compact, rosette-shaped bud made of leaves with a diameter of about 2 cm. The stem axis is short and covered with few or no withered leaves from the preseason.
The bud of the stipules is ovate, shaggy, 5 mm long and 3.5 mm in diameter at the base. The stipules themselves are 4.5 mm long, 3 mm wide and three-lobed. The middle lobe is divided into 3 segments. The central segment is divided into 3 lobes at the top. The outer lobes are fringed at the inner edges and at the tip. The lowest tip exceeds the length of the central segment.
The leaf blades are elliptical, 3.5 mm long and 2.5 mm wide. The longer tentacle glands are on the edge, the shorter ones on the inside. There are also some glands on the underside. The leaf stalks are up to 6 mm long, 1 mm at the base and taper to 0.8 mm at the leaf blade. They are partly semi-lanceolate and completely covered with some cylindrical, red-headed glands.
Flowering time is October to December. The one or two flower stems are 6 cm long. The lower two thirds are sparsely occupied with tiny glands. The upper third is densely covered with cylindrical, red-headed glands. The inflorescence is a coil of 3 to 6 flowers on approximately 2.5 mm long pedicels. The egg-shaped sepals are 2.5 mm long and 1 mm wide. The tips are irregularly toothed and covered with many transparent, cylindrical, red-headed glands. The metallic-orange, at the base red-brown petals are inverted ovate, 8 mm long and 6.5 mm wide. The tips are broken off and slightly notched.
The flower has 5 stamens . The threads are white, the anthers are white with red spots, and the pollen are yellow. The ovary, which is green at the base and blackish-brown at the tip, is broad, inverted ovoid, 0.8 mm long and 1.3 mm in diameter. The 3 to 5 white, slightly reddish, semi-upright styluses are 1.4 mm long. The scars are black-brown, predominantly inverted egg-shaped, 0.7 mm long and 0.5 mm wide. Different shapes and sizes of scars are not uncommon from population to population.
The formation of brood scales is typical for dwarf sundew : The narrowly elliptical, 0.8 mm thick brood scales are formed in large numbers from late November to early December and are approx. 1 mm long and 0.3 mm wide.
Distribution, habitat and status
Drosera platystigma occurs only on a small area in the extreme southwest of Australia. The plant thrives there on clayey sand or laterite and loam soils in open heathland or in open areas of the Jarrah forest. Known populations are found at Albany , Busselton , near the Stirling Range, and at Bannister .
Systematics
The name platystigma refers to the wide stigmas of this sundew ( platy "broad"; stigma "scar"). The species was described by Johann Georg Christian Lehmann in 1844 .
literature
- Allen Lowrie: Carnivorous Plants of Australia. Volume 2. University of Western Australia Press, Nedlands 1989, ISBN 0-85564-300-5 , p. 138.
