Encephalartos lehmannii

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Encephalartos lehmannii
Encephalartos lehmannii

Encephalartos lehmannii

Systematics
Order : Cycads (Cycadales)
Family : Zamiaceae
Subfamily : Encephalartoideae
Tribe : Encephalarteae
Genre : Bread palm ferns ( Encephalartos )
Type : Encephalartos lehmannii
Scientific name
Encephalartos lehmannii
( Eckl. & Zeyh. ) Clay.

Encephalartos lehmannii is a member of the cycads (Cycadales) and belongs to the genus of bread palm ferns ( Encephalartos ). It is also called Karoo bread palm fern in German.

features

The trunks are usually in twos or more due to root saplings. They are upright, up to 1.5 m high and 25 to 50 cm in diameter. The numerous leaves are straight or the tip is bent back downwards, they are 1 to 1.5 m long, 25 cm wide. The entire surface is hairy silver. The leaf stalk is 25 to 30 cm long, unreinforced and has a swollen base with a conspicuous, red-brown to yellow-brown collar. The rachis is slightly conical, smooth or provided with slight furrows. The lower leaflets are not reduced to thorns . The middle leaflets are 12 to 18 cm long, 17 to 19 mm wide, they stand at right angles from the rachis and rarely overlap. The leaf margin is flat and usually entire, rarely with one or two small thorns.

The female cones are single. They are erect, egg-shaped, 45 to 50 cm long and around 24 cm in diameter. The handle is short, stocky and hidden by cataphylls . The middle sporophylls are around 6 cm long. The side of the sporophyll lying on the surface of the cones is 3.5 cm high, 6 cm wide, actually green, with the thick hairs appearing black-red. The sarcotesta of the seed is red at maturity. The sclerotesta is slightly ovoid, 21 to 30 mm long, 16 to 18 mm in diameter, light brown with 7 to 11 light ribs in a lighter color.

The male cones are single. They are approximately cylindrical, upright, 37 to 49 cm long with a diameter of 10 to 11 cm, narrowing towards the ends. The color is green, with dense, short black-red hairs. The stem is 3.5 to 5 cm long, yellow and glabrous. A sporophyll is 4 to 4.5 cm long. The side of the sporophyll lying on the cone surface is 13 to 15 mm high and 30 to 35 mm wide.

The number of chromosomes is 2n = 18.

Distribution and locations

The species occurs in the Eastern Cape Province of South Africa , in the districts of Willowmore , Uitenhage, Steytlerville, Pearston and Bedford, especially in the catchment area of ​​the Groot and Sundays rivers. It grows on hot, dry sandstone hills in the Karoo bush together with Euphorbia . Usually it grows in full sunlight. The annual rainfall is 350 mm and less and falls in summer. Winters are cold and frosts are frequent.

The populations fell sharply towards the end of the 20th century. The main reason is the popularity of the species as an ornamental plant. Other factors are the feeding by domestic goats and the slow regeneration of the plants. A weevil from the Curculionidae family parasitizes the seeds. In 2002, there were no protective measures in place for the endangered species.

use

Encephalartos lehmannii is widely cultivated as an ornamental plant. In the shape of her original scientific name, she was the patron saint of the music album "Zamia lehmannii - Songs of Byzantine Flowers" by the Australian band SPK in 1986 .

Botanical history

The species was described as Zamia lehmannii after the director of the Hamburg Botanical Garden, Johann Georg Christian Lehmann , an important explorer of the cycads . After the formation of the genus Encephalartos , Lehmann himself placed it in this genus. In 1933, several species that had previously been regarded as independent were integrated into Encephalartos lehmannii , including: Encephalartos pungens , Encephalartos elongatus , Encephalartos spinulosus , Encephalartos mauritianus . In 1965 RA Dyer separated the two species Encephalartos trispinosus and Encephalartos princeps from the species.

literature

  • Loran M. Whitelock: The Cycads. Timber Press, Portland OR 2002, ISBN 0-88192-522-5 , pp. 213 f.

Individual evidence

  1. ↑ Walter Erhardt among others: The great pikeperch. Encyclopedia of Plant Names . Volume 2, page 1387. Verlag Eugen Ulmer, Stuttgart 2008. ISBN 978-3-8001-5406-7
  2. ^ Tropicos. [1]

Web links

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