Brachystelma
Brachystelma caffrum
Brachystelma is a plant genus that to the subfamily of milkweed plants ( Asclepiadoideae ) within the family of the dogbane family ( Apocynaceae ) belongs. Brachystelma is according to the genus Ceropegia the most species-rich genus within the tribe Ceropegiae. The genus name is derived from the Greek brachys for short and STELMA for crown, garland, wreath and indicates the formation of a corona.
- 5.1 Literature
- 5.2 online
- 5.3 Notes and references
Description
Appearance and leaves
The Brachystelma species are deciduous, wurzelsukkulente, perennial herbaceous plants. These geophytes are distinguished by the possession of small or large subterranean hypocotyl or root tubers or spindle, fleshy thickened roots. The white- yellow-fleshed tubers are edible or in some species. From the usually somewhat depressed apex of the tubers originate in the long growing season to a number of 2 to 100 cm, usually one-year shoots. The tiny to large leaves may be stalked or sessile. The leaf blades are linear to ovate and entire. Rare ( sub-) succulent leaves are formed. Most also Nebenblatt rudiments are present.
Inflorescences and flowers
Be a short, but usually formed without inflorescence stem the scheindoldigen inflorescences that contain one to many flowers end or laterally. The flowers open often in pairs or one at a time. The flower stalks are 3 to 50 mm long.
The hermaphrodite flowers are radial symmetry and fünfzählig. The five sepals are ovate - lanceolate to subulate. The corollas have a diameter of 5 to 60 mm and vary in shape from flat, bell-shaped to bechrig. The five corolla lobes are usually spread out flat wheel-shaped, rarely beaten back to back. In some species the corolla lobes are also upright or are connected at the tips to form a balloon-like structure. The seated or pedunculated Nebenkrone can be double-breasted or single-breasted. The staminal Nebenkronzipfel are usually rectangular and lie on the anthers. The interstaminalen Nebenkronzipfel are at the base bechrig or cup-shaped, divided into five lobes at the upper end. The hairy lobes are usually divided into two, rarely almost degenerated. The fused to a short tube at the base stamens are rectangular and lie on the stylus head, rarely do they stand upright. The nearly square pollinia are ovoid or pear-shaped.
Fruit and seeds
There shall be one or two follicles per flower. If two fruits formed, they can almost be opposite or also run approximately parallel to each other. They are spindle-shaped, depending on the type between 30 to 200 m ( tens of meters long fruit? ) Long. The end is usually pointed or beaked. The surface is hairless and provided substantially smooth or with longitudinal furrows. The pericarp is thin, papery to thick-fleshed. The individual fruit contains approximately 10 to 20 seeds. The black and brown seeds possess significant lateral wings. The white or cream-colored head of hair is 15-15 mm long.
Synecology
The flowers of Brachystelma species often give off a scent aasartigen ( carrion flowers ) in order to attract blowflies, which pollinate the flowers.
Occurrence
The Brachystelma species grow mainly in African drylands. But you are completely missing in Madagascar, North Africa and Arabia. Some species were also found in India and Sri Lanka, as well as in East Asia. A single species grows in Papua New Guinea and northern Australia.
System
The genus Brachystelma in 1822 by John Sims in the Botanical Magazine, Volume 49, panel 2343 with the type species Brachystelma tuberosa whose basionym Stapelia tuberosa Meerb. is set up.
For Brachystelma R.Br. There are a variety of synonyms, which are due to the inclusion of several other genera; Synonyms are: Aulostephanus Schltr, Blepharanthera Schltr, Brachystelmaria Schltr, Craterostemma K.Schum, Decaceras Harv, Dichaelia Harv, Eriopetalum Wight, Kinepetalum Schltr, Lasiostelma Benth, Macropetalum Burchell ex Decaisne, Micra Rochester Harv, Microstemma. .. .. .. .. R.Br., Siphonostelma Schltr. , Tapeinostelma Schltr. , Tenaris E.Meyer.
There are about 100 to 120 species in the genus Brachystelma. So far there is no revision for the full genus Brachystelma. Patrick Siro Masinde created in 2007 only a revision of the East African taxa. A rough classification of the species is made by Ulrich Meve in Sukkulentenlexikon based on the shape of the Wurzelsukkulenz. It is distinguished by fleshy, cylindrical to spindle-shaped roots ( 1) and after tuberous roots ( 2). The compilation of the species follows the Brachystelma Checklist with a few additions (since then newly described species).