Nature's valley: A refugium for rare southern cape forest species

Three rare forest species grow in abundance in the sheltered, low-lying Grootrivier valley and hills surrounding Nature’s Valley, Southern Cape: Strychnos decussate a tree confined to alluvial terraces along the river; Hippobromus pauciflorus , a shrubby tree of dry scrub forest; and Strelitzia alba , a wild tree banana endemic to the Southern Cape and most abundant in this area. S.decussata has a taproot and requires deep, well-drained sites such as alluvium and sand dunes, for successful establishment. It is suggested that S.decussata and H. pauciflorus were cut off from their migration route along dunes of the presently off-shore platform, while S.alba evolved from S.nicolai due to this isolation.