Pterodiscus
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Pterodiscus is a genus of plants from the sesame family. The generic name is derived from the Greek pteros for wing and the Latin discus for disk and refers to the structure of the fruit.
description
They are perennial herbaceous plants with a short, persistent caudex . Annual shoots are formed at the tip of the caudex in each growing season. These can be up to 50 cm long. The stalked leaves are slightly succulent and very differently shaped in the blade. They can be linear or lanceolate to broadly elongated or elliptical. The edge of the leaves is either entire, curved, toothed, pinnate or pinnate.
The yellow, bright orange, red or purple, rarely white, flowers appear individually from the leaf axils. The narrow, cylindrical corolla tube , often slightly sagging at the base, is narrowed in the lower part or, rarely, funnel-shaped in the upper part. The lobes of the same size at the end of the expanded coronary hem are roughly circular to elliptical. The four stamens are enclosed in the tube, the bars of which spread apart. A fifth stamen is usually present as a staminodium .
The two ovary compartments are undivided. The sometimes heavily lignified fruit, which remains closed, is slightly compressed on the sides and has a 1 to 12 mm wide, mostly parchment-like wing on all four outer edges . The spongy mesocarp contains large cavities. The side view of the fruit including the wings is broadly elliptical, egg-shaped, circular or transversely elliptical (in Pterodiscus aurantiacus ). It is often slightly asymmetrical in shape, with a margin at the tip or with attached tips. Usually it is stranded at the base. The fruit body is usually widest in the lower half. The upper part is sterile and often forms a beak.
The seeds are either 1 to 3 pieces in each compartment and are then elongated with a smooth seed coat. Or they are 4 to 8 pieces, rarely up to 10 pieces in each compartment and are then egg-shaped with a wrinkled seed coat.
Distribution and systematics
The species of the genus Pterodiscus are common in the southwest, south, east and northeast of Africa.
The genus was described in 1844 and includes 12 species. The type species of the genus was Pterodiscus speciosus Hook. certainly.
- Pterodiscus angustifolius Engl.
- Pterodiscus aurantiacus Welw.
- Pterodiscus brasiliensis (J.Gay ex DC.) Asch.
- Pterodiscus coeruleus Chiov.
- Pterodiscus elliottii Baker ex Stapf
- Pterodiscus kellerianus Schinz
- Pterodiscus luridus Hook.f.
- Pterodiscus ngamicus N.E.Br. ex Stapf
- Pterodiscus ruspolii Engl.
- Pterodiscus saccatus S.Moore
- Pterodiscus speciosus Hook.
- Pterodiscus undulatus Baker f.
swell
- Urs Eggli (ed.): Succulent lexicon. Dicotyledons (dicotyledons) . Eugen Ulmer, Stuttgart 2002, ISBN 3-8001-3915-4 , pp. 375-379 .
