Umbrella Thorn (Acacia luederitzii and Acacia reficiens)

THESE two species look very similar. Generally speaking, the bastard umbrella thorn is in every way larger than the false umbrella thorn. It becomes a taller tree; the leaves have more pinnae; the pinnae have more leaflets and the pods grow somewhat larger than those of the false umbrella thorn.

The bastard umbrella thorn or Kalahari sand acacia (Acacia luederitzii) A. Baster haak-en-steek; G. Lüdritzakazie

is more common in eastern Namibia and on sandy soils. It reaches a height of 5 – 6m, frequently with an umbrella-shaped crown. Its bark is very rough and fissured and purplish brown-black on old branches. Young branchlets are covered with dense grey or whitish hair.

Pairs of short hooked thorns and pairs of straight white thorns occur on the same tree; the straight thorns may be brown when young.

The leaves have 3 – 9 pinnae pairs with 10 – 26 leaflet pairs per pinna. They are very small and their margins are fringed with fine spreading hairs (hand lens).

White ball-shaped flowers occur from Nov – Feb and develop into flat, straight, leathery, grey-brown to purplish brown pods measuring 3,2 – 13cm x 1 – 2 cm.

General: springbuck and giraffe prefer the flowers of both species but they are not as popular as other acacias. No medicinal properties are mentioned.

The False umbrella thorn (Acacia reficiens)A. Vals haak-en-steek;

G. Rotrindenakazie; H. Omungondo; N. !Gus; Nd. Omutsiyamatsi; Ky. Omutyuula is more common in western Namibia and mostly occurs on stony ground. It usually is a V-shaped many-stemmed shrub, about 3 m high, frequently with an umbrella-shaped crown. The bark is conspicuously reddish brown especially on young branches. The paired thorns are mostly hooked but long straight thorns often also occur on this tree, especially on new growth.

The leaves have 1 – 4 pinnae pairs and 5 – 11 leaflet pairs per pinna with no hairs on leaflets or only slightly hairy (hand lens), White ball-shaped flowers appear in January – February and give rise to pods measuring 2,6-8,8 x 0,6-1,1 cm, which are flat, straight, thinly woody, mahogany red, and at most 10 mm wide. This tree may become invasive and is particularly difficult to push over by bulldozer.

General: elephant eat the bark and the leaves, rhino the branches. It is used medicinally to promote expulsion of afterbirth and to treat difficulty with urinating in men.

Acacia reficiens is the more common and widespread of the two species, occurring in a broad band from the south-eastern border of Namibia throughout the central areas, reaching into the central Namib in the west and almost up to the Kunene and the Okavango in the north. A. luederitzii is found in a narrower strip from about Rehoboth up to the Okavango River. In the central parts of Namibia the two species overlap and may easily be confused especially since A. reficiens in these areas may also become a sizeable tree.

A. luederitzii was named either after the merchant and founder of Lüderitzbucht, Franz Adolf Lüderitz or after his brother August Lüderitz, who collected plants in the former German South West Africa.