Strelitzia caudata R.A.Dyer
Common names: Transvaal wild banana (Eng.); Transvaal wildepiesang (Afr.); isigude saseMpumalanga (Nguni)
SA Tree No: 33
Strelitzia caudata is one of three arborescent banana-like Strelitzia species occurring in southern Africa. It is a good focal point for a mid-size to large garden.
Strelitzia caudata is unbranched and multi-stemmed, growing up to ± 6 m tall with a stem diameter of 100 to 150 mm. The older stems are woody with leaf scars and often have suckers at the base. Leaves are tufted at the apex; the petiole is pink, 1.5-1.7 m long and narrowed towards the base; the leaf blade is oblong, 1.5-1.7 m long and 800-850 mm broad. The leaves are leathery, opposite, green to greyish and the leaf blade becomes torn and tattered by wind as it ages.
The inflorescence consists of a single purplish, boat-shaped spathe bearing several flowers in autumn to winter (May to July). The spathe is at right angles to the peduncle, claret- coloured and glaucous, 300 mm long, 60-65 mm high and about 35 mm thick. It tapers to a slender tip and has mucilage exuding over the side which facilitates the emergence of flowers that are tightly packed. Sepals are white, sometimes mauve-tinged at the base, with the upper pair widely diverging from the lowest; the upper abaxial pair is linear-lanceolate 150-200 mm long and 30 mm broad. The lower sepal is about as long as the other two, boat-shaped, sharply keeled with the keel extending about its middle into a slender lobe or tail 15-25 mm long. Petals light mauve throughout or only towards the base, two lower ones about 120-150 mm long with basal portions forming a boat-shaped depression 20-30 mm wide, the apical portions form a sagittate (resembling an arrow-head) blade 80-100 mm long and 20 mm wide, with basal lobes obtuse, 50-60 mm long and 7-8 mm broad. The upper petal is ovate, 25-35 mm long including the cusp (sharp point) and 10-12.5 mm broad. The filaments are 30-40 mm long and anthers 55-90 mm long. The style is 160-175 mm long including the stigma. The ovary is irregularly triangular.
The fruit is a hard, woody, three-lobed capsule 50-70 mm long, 20-30 mm broad across the sides and splits from the apex in summer (November to February). The seeds are round, black to brown with a yellow aril.
It is difficult to distinguish S. caudata from S. alba and S. nicolai, the other tree-like strelitzias found in southern Africa, unless they are growing in their natural habitat (geographic locality), because they occur in different areas. Otherwise they can be separated by scrutinising their inflorescences. S. caudata is more closely related to S. alba and they both have simple inflorescences with a single spathe, but the petals of S. caudata are light mauve to blue with the basal lobes shaped like those of an arrow head and with a tailed lower sepal. The petals of S. alba are white with rounded lobes and the lower sepal is not prominently tailed. S. nicolai has blue petals and the inflorescence consists of several spathes.
The conservation status of S. caudata is regarded as being of Least Concern in the IUCN Red Listing (Raimondo et al. 2009).
Distribution and habitat
S. caudata occurs in southern Africa from Swaziland and Mpumalanga to the Eastern Highlands of Zimbabwe. It is found inland in open, rocky, but moist situations in and near Afromontane forest.
Derivation of name and historical aspects
Strelitzia is named in honour of Queen Charlotte, wife of George III, from the house of Mecklenburg-Strelitz. The specific name caudata refers to the slender tail-like projection from the middle of the keel of the lowest sepal. This was first noticed in this species; later, however, it was also observed in S. alba.
As with other strelitzias, sunbirds may be the chief pollinators, but this has still to be established for this species. The role of sunbirds in Strelitzia pollination needs to be investigated as they have been observed "robbing" the flowers by taking nectar and by-passing the pollination mechanism.
There are no known specific recorded traditional or cultural uses for Strelitzia caudata.
Growing Strelitzia caudata
Strelitzia caudata is propagated easily from seed. Hand pollination is necessary to get true viable seed. Different clones should be used for pollination since it is self-sterile or will produce very little seed when forced. The little seed we have managed to germinate we treat by scarifying the seed in 90% sulphuric acid for five minutes, then rinsing it under running water. This is followed by soaking in ethylene (Ethrel) 2 000 ppm for 48 hours. Alice Notten (2002) provides the following note on growing 'Mandela's Gold' strelitzias (a technique we use for all strelitzias) :
"Sow in seed trays filled with a well-drained soil medium at a depth of 1 to 1½ times the size of the seed. A constant temperature of 25°C is most suitable for germination, as low temperatures retard germination. Seedlings should be a good size before being transplanted (two to three leaves) into a well-drained potting medium. In our nursery we have found that the young plants are best grown in semi-shade, as the leaves tend to burn in direct sunlight. Regular repotting allows the young plant to develop rapidly. Restricting the root development retards growth."
- Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of southern Africa, edn 3. Struik, Cape Town.
- Dyer, R.A. 1946. Strelitzia caudata. The Flowering Plants of Africa 25: plate 997.
- Dyer, R.A. 1977. Strelitzias of the Eastern Cape. The Eastern Cape Naturalist 61: 10-12.
- Germishuizen, G. & Meyer, N. L. (eds). 2003. Plants of southern Africa: an annotated checklist. Strelitzia 14. National Botanical Institute, Pretoria.
- Notten, Alice. 2002. Strelitzia reginae Aiton 'Mandela's Gold' [from the SANBI's PlantzAfrika web-site http://www.plantzafrica.com/plantqrs/strelitregmandelagold.htm ]
- Raimondo, D., Von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. & Manyama, P.A. (eds) 2009. Red List of South African plants. Strelitzia 25.South African National Biodiversity Institute, Pretoria.
Kirstenbosch National Botanical Garden
Plant Type: Tree
SA Distribution: Limpopo, Mpumalanga
Soil type: Sandy, Clay, Loam
Flowering season: Autumn, Winter
PH: Acid, Neutral
Flower colour: Blue, Purple, White, Mauve/Lilac
Aspect: Full Sun, Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Average