Encephalartos senticosus
| Encephalartos senticosus | ||||||||||||
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Encephalartos senticosus |
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| Scientific name | ||||||||||||
| Encephalartos senticosus | ||||||||||||
| Vorster |
Encephalartos senticosus is a member of the cycads (Cycadales) and belongs to the genus of bread palm ferns ( Encephalartos ).
features
The trunks are tree-shaped, upright or leaning, and stand individually or in groups due to root saplings. The trunk is up to 4 meters high and 30 cm wide. The crown is slightly woolly.
The numerous leaves are upright, straight, stiff, sometimes slightly curved back and down. The leaves are 1.1 to 2 m long and 16 to 28 cm wide. The bald petiole is 5 to 20 cm long. The leaflets are shiny dark green, usually not overlapping and are at an angle of about 30 ° to the front; the two opposite leaflets form an angle of 135 °. The basal leaflets are reduced to thorns . The middle leaflets are 12 to 18 cm long, 14 to 22 mm wide, and are 2 to 2.5 cm apart. The leaf margin is usually serrated, often with several thorns. The tip is sharp.
There are two or three female cones on the plant. They are egg-shaped, 40 to 45 cm long and 22 to 30 cm in diameter. The color is pale apricot-yellow, the surface is sparsely covered in felt-like hair. The stem is short so that the cone appears seated. The sporophylls are 5.5 to 6 cm long. The side of the sporophyll lying on the surface of the cones is smooth, pyramidal 10 to 12 mm high, 35 to 40 mm high, 45 to 50 mm wide. The sarcotesta of the seed is bright red at maturity. The sclerotesta is ovate, 24 to 29 mm long, 19 to 20 mm in diameter, with 12 to 14 distinct longitudinal ribs.
There are three or four male cones. They are upright, narrowly ovate, 30 to 50 cm long with a diameter of 12 to 15 cm. The color is orange-yellow, hairy light brown. The stem is 10 cm long and 2.5 to 4.5 cm wide. The sporophylls are 3 to 3.5 cm long. The side of the sporophyll lying on the cone surface is rhombic, 15 to 18 mm high and 35 to 40 mm wide, and forms a downwardly curved beak. In the upper part of the cone they are slightly hairy brown. The sporangia stand in a single, slightly heart-shaped spot on the underside.
Distribution and locations
The species occurs in South Africa in the province of KwaZulu-Natal in the Lebombo Mountains , from south of the Jozini Dam northwards to a few kilometers beyond Siteki in Swaziland . It grows on dry, exposed rocks and slopes between boulders and coppice, mostly in full sunlight. It is mostly found at 400 to 800 m above sea level in areas with 625 to 750 mm annual, mostly summer, precipitation. It is one of the most common cycads in South Africa. Despite partial loss of habitat and collecting activities, the species should be safe.
Botanical history
The species was first described in 1996 , but the plants had been known for a long time. They have long been mistaken for Encephalartos lebomboensis , which consisted of two different forms. When Piet Vorster wanted to describe the form known as the rare Piet-Retief as a separate species, he noticed that the type specimen of Encephalartos lebomboensis is a representative of this Piet-Retief form. The more common form, long known as Encephalartos lebomboensis , now had to be described as a new species, Encephalartos senticosus .
In the 1960s, the species was the subject of a major rescue operation called Operation Wildflower : before the Pongola River was dammed by a dam at Pongola Poort, over 6,000 specimens of this species were recovered from the floodplain, along with many other rare plants.
supporting documents
- Loran M. Whitelock: The Cycads. Timber Press, Portland OR 2002, ISBN 0-88192-522-5 .
Web links
- Encephalartos on Cycad Pages of the Royal Botanic Gardens Sydney.
- Encephalartos senticosus inthe IUCN 2013 Red List of Threatened Species . Listed by: Donaldson, JS, 2009. Retrieved April 28, 2014.