Strelitzia alba (Cape strelitzia)

Life > eukaryotes > Archaeoplastida > Chloroplastida > Charophyta > Streptophytina > Plantae (land plants) > Tracheophyta (vascular plants) > Euphyllophyta > Lignophyta (woody plants) > Spermatophyta (seed plants) > Angiospermae (flowering plants) > Monocotyledons > Order: Zingiberales > Family: Strelitziaceae > Genus: Strelitzia

A Male red-winged starling, Onychognathus morio, taking nectar from a flower of Strelitzia alba on the Garden Route, Western Cape, South Africa. [photo Colin Paterson-Jones ©]

A male Greater double-collared sunbird (Cinnyris afer) taking nectar from a flower of Strelitzia alba on the Garden Route, Western Cape, South Africa. [photo Colin Paterson-Jones ©]

A male Cape Weaver (Ploceus capensis) taking nectar from a flower of Strelitzia alba on the Garden Route, Western Cape, South Africa. [photo Colin Paterson-Jones ©]

A male Amethyst Sunbird (Chalcomitra amethystina) taking nectar from a flower of Strelitzia alba on the Garden Route, Western Cape, South Africa. [photo Colin Paterson-Jones ©]

Identification

A large tree-like strelitzia, growing to 10 m tall.

Of the three tree-like strelitzias found in southern Africa, Strelitzia alba is distinguished by having white, not blue, petals (however, occasionally white in Strelitzia nicolai) and by having a simple flowerhead, not compound (one flowerhead arising from another) as in Strelitzia nicolai. Note that it is the arrow-like structure of a Strelitzia flower that consists of two petals (with style and stamens running between) while the three large, erect, showy petal-like structures are actually sepals - these sepals are white in all three species of tree-like strelitzias. There is a third petal that is inconspicuous.  

The fruit is a 3-lobed woody capsule. The seed is black with a yellowish woolly aril.

Distribution and habitat

Its native distribution is confined to evergreen forests in the region from the Knysna district in the Western Cape through to the Humansdorp district in the Eastern Cape.

Phenology

Can flower at any time of year, but mainly from July to December.

Fruit can also be present on the plant at any time of year, but mainly from October to February.

Ecological interactions

• Pollinated by, and a source of nectar for:
  • starlings
    • Onychognathus morio (Red-winged starling) - see image above.
  • sunbirds
    • Chalcomitra amethystina (Amethyst Sunbird) - see image above.
    • Cinnyris afer (Greater double-collared sunbird) - recorded in Palmer & Pitman (1972). See also image above.
    • Cinnyris chalybeus (Southern double-collared sunbird, Lesser double-collared sunbird) - recorded in Palmer & Pitman (1972)
  •  weavers
    • Ploceus capensis (Cape Weaver)

References

• Palgrave, K.C. and Palgrave, M.C. 2002. Trees of Southern Africa. 3rd Edition. Struik Publishers, Cape Town.
• Palmer, E. and Pitman, N. 1972. Trees of Southern Africa covering all known indigenous species in the Republic of South Africa, South-West Africa, Botswana, Lesotho and Swaziland. Volume 1. A.A. Balkema, Cape Town.