Drosera sewelliae
| Drosera sewelliae | ||||||||||||
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| Drosera sewelliae | ||||||||||||
| Diels |
Drosera sewelliae is a carnivorous plant from the genus sundew ( Drosera ). It belongs to the group of so-called dwarf sundews and is native to southwestern Australia.
description
Drosera sewelliae is a perennial herbaceous plant . This forms a compact, rosette-shaped bud made of leaves with a diameter of about 2.5 cm. The stem axis is 1 cm long and covered with the withered leaves of the preseason.
The bud of the stipules is ovate , shaggy, 5 mm long and 4 mm in diameter at the base. The stipules themselves are 3.5 mm long, 3.5 mm wide, 1 mm wide at the base and three-lobed. The middle lobe is divided into 3 segments. The side lobes are somewhat divided at the top. On the inner edge near the tip is an additional fringe that is almost as long as central lobes.
The leaf blades are elliptical , 2.2 mm long and 2 mm wide. The longer tentacle glands are on the edge, the shorter ones on the inside. A few glands can be found on the underside. The leaf stalks are 8 mm long, 0.9 mm long at the base and taper to 0.7 mm at the leaf blade. Some are semi-lanceolate with a raised rib along the entire petiole. They are completely covered with tiny glands.
Flowering time is October. One, and rarely two, flower stalks are 6 cm long and covered with glands. The glands become denser towards the tip. The inflorescence is a coil of 6 flowers on approximately 2 mm long pedicels. The elliptical sepals are 2.5 mm long and 1.5 mm wide. The edges and the tips are fringed and covered with 0.5 mm long, white, cylindrical, red-headed glands. The entire surface is also covered with these glands. The petals are metallic-orange and red-brown at the base. They are very broad , obovate , 9 mm long and 8.5 mm wide. The tips are notched irregularly.
The five stamens are 2 mm long. The stamens are black-brown, the anthers are white with red spots and the pollen are pale yellow. The brown-black at the top, center and reddish in the green at the base ovary is obovate, pressed, 0,5 mm long and 1 mm in diameter. The 5 black-brown, horizontal, flattened round styluses are 3.5 mm long. The scars are black, glabrous, 0.4 mm in diameter, and formed on the tip of each stylus.
The formation of brood scales is typical of dwarf sundews.The elliptical, 1 mm thick brood scales are formed in large numbers in the Australian autumn (in cultivation in the northern hemisphere from late November to early December) and are approx. 2 mm long and approx. 2 mm wide 1.4 mm.
The flowers of this species are just as large as the rosette itself. Drosera sewelliae has the largest flowers of all dwarf sundew . The appearance of blooming, compact colonies of this plant is spectacular.
The number of chromosomes is 2n = 18.
Distribution, habitat and status
Drosera sewelliae occurs only on a small area in the extreme southwest of Australia. The plant thrives there on laterite and silica-containing sandy soils in light, open forest. The only known population is at Chittering Valley .
Systematics
Ludwieg Diels named this species after a Miss Sewell who had collected the plant, but whose first name is nowhere mentioned, not even in Diels' first description. Drosera sewelliae can be recognized by its 5 long and dark styluses, all of which have a spherical stigma .
literature
- Allen Lowrie: Carnivorous Plants of Australia. Volume 2. University of Western Australia Press, Nedlands 1989, ISBN 0-85564-300-5 , p. 166.
Individual evidence
- ↑ Drosera sewelliae at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
Web links
- D. Röpert (Ed.): Digital specimen images at the Herbarium Berolinense. , published on the Internet: type specimen with drawing