Brachystelma barberiae
| Brachystelma barberiae | ||||||||||||
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Brachystelma barberiae , illustration |
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| Brachystelma barberiae | ||||||||||||
| Harv. ex Hook.f. |
Brachystelma barberiae is a species of plant from the subfamily of the asclepiadoideae (Asclepiadoideae). It isnative to southern Africa .
description
Vegetative characteristics
Brachystelma barberiae is a perennial , herbaceous geophyte with a hypocotyl bulb as a perennial organ that grows half or fully in the ground. The flattened, spherical tuber can reach a size of about 7 by 20 cm and is sunk in the middle. With age, the shape becomes irregular. All above-ground parts of the plant are coarsely haired and, when injured, release a watery milky sap . One to a few, upright or prostrate stems with a maximum length of 10 cm are formed.
The tufted stems are annual and die off completely in the dry season. The opposite leaves are short-stalked and densely hairy. The undivided leaf blade is elongated, lanceolate or obovate with a length of up to 10 cm and a width of up to 2.5 cm.
Inflorescence and flowers
The flowering time in South Africa is in spring and early summer (mostly October to December). The two (to three), mostly opposite, almost terminal, capid, dold-like inflorescences contain up to 25 flowers (up to 50 flowers). The flowers open at the same time (or in quick succession within two to three days) and smell intensely of feces . The flower stalks are 1 to 2 cm long and hairy downy.
The hermaphrodite flowers are radially symmetrical and five-fold. The five sepals are subpulate with a length of about 1 cm. The 2 to 4.5 cm long corolla has a bell-shaped corolla tube 4 to 5 × 5 to 7 mm in size. The color of the corolla tube is yellowish on the inside with red-brown bands, the lobes are red-brown. The outside of the flower is greenish in color. Except for the corolla tube, all parts are hairy. The very elongated petal lobes are triangular at the base and quickly become narrow linear. The tips of the corolla lobes are connected to each other and form a broad, egg-shaped cage-like structure that is wide open between the lobes. The sessile, with a diameter of 4 to 5 mm cup-shaped to bell-shaped corolla is 1.5 mm high and red-brown in color. The pocket-shaped interstaminal corolla lobes have a obtuse-triangular upper edge with a flat incision. The staminal corolla lobes are about 1 mm long and shaped like a linear tongue and lie on the stamens . The broad oval pollinia are 0.4 mm long and 0.3 mm wide.
Fruits and seeds
Usually two fruits develop per flower, sometimes only one fruit (and the other fruit withered). They are comparatively very large for the small plants, stand upright or are ascending. The smooth follicles are fusiform with a length of about 5 cm and a diameter of about 1 cm with a thick pericarp . The seeds are tightly packed in the fruit. The white head of hair of the seeds is used for spreading by wind ( anemochory ). The fruit ripens for almost a year.
ecology
The flower contains some nectar and smells extremely of feces. This attracts flies from far away. If the fly tries to get the nectar supply, it often tears off the pollinia that stick to the proboscis and can thus possibly be transported to another flower. The color and the mobile hair are another stimulus to lay eggs on the flower.
The size of the tuber correlates with the age of the plant. When this has reached a diameter of 20 cm, the plant is around 10 to 20 years old. It is a storage organ for water and nutrients.
Food relationships and human use
The tubers of Brachystelma barberiae are mainly eaten in their home area by porcupines (Hystricidae), baboons ( Papio ), rodents and also insects . They are also edible for humans. In rural areas they were eaten when other food was scarce. For the San, they supplemented their daily diet. They were also a reserve of fluid in the arid areas where this species grows.
Occurrence
Brachystelma barberiae is found in Botswana , Zimbabwe and the South African provinces of Eastern Cape , KwaZulu-Natal , Mpumalanga , North Cape and Northwest .
It grows in well-drained, gravelly, sandy to loamy soils in full sun or partial shade in grasslands and in the savannah. It thrives at altitudes between about 400 and 1300 meters. Although it is generally rare, it can be very common locally.
Taxonomy and nomenclature
The first description of Brachystelma barberiae was in 1866 by Joseph Dalton Hooker in Curtis's Botanical Magazine , Volume 93, Plate 5607 (+ 2 unnumbered pages of description). For the first description he resorted to a manuscript name of William Henry Harvey , who had already died at the time of publication . The name Hooker had been given by the nature painter and botanist Mary Elizabeth Barber ; Harvey had left no written record of the new species. The name was later incorrectly corrected to barberae . The specific epithet barberiae is a correct original spelling and is based on the previously Latinized surname Barber (= fem. Barberia) by Mary Elizabeth Barber. Both spellings are in use (see Meve and Flora of Zimbabwe ). The type specimen was collected by Mary Elizabeth Barber's brother Henry Bowker on the "Isomo River" (recte Tsomo River ). The Bowker family lived in Grahamstown , Sarah Baartman District , Eastern Cape Province , Republic of South Africa ). A synonym for Brachystelma barberiae Harv. ex Hook. f. is Dichaelia barberiae (Harv. ex Hook. f.) Bullock.
The specific epithet barberiae honors the botanist Mrs. Mary Elizabeth Barber (1818–1899), who drew the original illustration of Brachystelma barberiae .
swell
literature
- Ulrich Meve: Brachystelma . In: Focke Albers, Ulrich Meve (Hrsg.): Succulents Lexicon Volume 3 Asclepiadaceae (silk plants). Eugen Ulmer Verlag, Stuttgart 2002, ISBN 3-8001-3982-0 , pp. 17-43.
Individual evidence
- ↑ a b c d e f g data sheet of Brachystelma barberae at PlantZAfrica.com
- ↑ Joseph Dalton Hooker: Brachystelma barberiae Mrs. Barber's Brachystelma. In: Curtis's Botanical Magazine , Volume 92 (3.ser., Vol. 22), 1866, plate 5607 + 2 pages of description. First description scanned at biodiversitylibrary.org .
- ↑ Brachystelma barberiae Harv. ex Hook. f. in the Flora of Zimbabwe
- ↑ Type of Brachystelma barberiae Harv. ex Hook. f. (family Asclepiadaceae)
- ↑ Entry in Tropicos .
- ^ Alan Cohen: Mary Elizabeth Barber, the Bowkers and South African Prehistory. In: The South African Archaeological Bulletin , Volume 54 (170), 1999, pp. 120-127. Online at JSTOR
