Alsophila dregei, synonymCyathea dregei, is a widespread species of tree fern in southern Africa. Within South Africa, it co-occurs with the indigenousforest tree fern and the invasive Sphaeropteris cooperi from Australia. Further north, outside of South Africa, it coexists with an additional two tree fern species, A. manniana and A. thomsonii. This species is locally known as the common South African tree fern or grassland tree fern. It is commonly known as the gewone boomvaring in Afrikaans.
Description
Key characteristics
Alsophila dregei has an erect, stout trunk and is up to tall and 20–45 cm in diameter. It is a variable species, usually having a thick trunk and dense crown. It is occasionally branched. Fronds are tripinnate and may reach 3 m in length. They are characteristically large and arching, with the lowestpinnae usually reduced. The upper surface of fronds is glabrate, while the lower surface may be tomentose. The rachis and stipe are brown in colouration and have a rough surface. The stipe is covered in brown scales. Up to twelve sori occur per group per pinnule.
It can be distinguished from the forest tree fern by its thick trunk, and by its smallest leaflets. The leaflets of A. dregei have smooth margins, while those of A. capensis are serrated. Each leaflet of A. dregei has multiple seedcases on its underside, while a leaflet of A. capensis has only one per leaflet. The fronds of A. capensis come off lower, and it usually has several small, residual leaf remnants, which sprout in tufts among its fronds at the top of its stem. The only other indigenous tree ferns of the southern African region, Alsophila manniana and A. thomsonii, are both native to Zimbabwe. They can be distinguished from A. dregei by stem, stalk and frondappearance. A. manniana has sharp spikes on a slender trunk and frond stems. A. thomsonii has light-coloured, twisted hairs under its leaflets. The invasive Sphaeropteris cooperi can be distinguished from A. dregei by the hairy white and brown scales on the new unfurling leaf stipes and sometimes by faint serrations on the leaflets.
Alsophila dregei is rarely common in cultivation as an ornamental plant, especially in South Africa and Australia. Plants should be sheltered and grown in richhumus, with a constant supply of moisture. This species can survivelight frosts with little damage.