Strelitzia reginae is one the most popular horticultural perennial around the world. It flowers for long periods with its vivid orange and bright purple/blue inflorences and is an ideal pot plant and cut flower subject.
The crane flower is a tufted, evergreen, acaulescent (stemless) perennial herb up to 1,5 m tall and 2 m in diameter. The roots are fleshy and finger-like and ± 25 mm in diameter. The leaves are distichous (opposite and arranged fan-like in one plane), banana-like with the leaf blade 500 x 100 mm, and the margins can sometimes be red-edged. The inflorescence stalk is 700 mm tall with 4-6 flowers that emerge in succession in a boat-shaped spathe ± 200 mm long, producing a mucilaginous substance when in bloom. The flowers have orange sepals and blue/purple petals (May to December). The fruit is a hard woody capsule that splits from the apex in summer (August to February). The seeds are round, black to brown in colour with a yellow aril (a tuft of hairs). S. reginae is one of five Strelitzia species in southern Africa: S. alba, S. juncea, S. nicolai and S. caudata.
Strelitzia reginae is not threatened.
Distribution and habitat
Strelitzia reginae occurs naturally only in South Africa: eastern coast, from Humansdorp to northern KwaZulu-Natal in coastal bush and thicket. It grows along river banks in full sun, however sometimes it occurs and flowers on margins of forest in shade.
Derivation of name and historical aspects
Stelitzia is named in honour of Queen Charlotte, wife of George III, from the house of Mecklenburg-Strelitz. The specific name reginae is Latin and means 'of the queen'.
Bees are common visitors when the spathe is in flower. Sunbirds may be the pollinator, but this has still to be proven. The role of sunbirds in Strelitzia pollination needs to be investigated, as they have been observed "robbing" the flowers by taking nectar but by-passing the pollination mechanism. Birds eat and disperse the seed. In nature, where its distribution overlaps with that of S. juncea, in the Humansdorp District, they hybridise easily.
In the late 90's Mr John Winter, former Curator of Kirstenbosch, started a programme of selecting plants with desirable characteristics. The programme has continued under the author and has produced the following selections: F3 dwarf orange, F2 dwarf broad leaf Mandela's Gold, F3 thin & long flower stock for cut flowers and the deep red spathe selection. The plant will be released to the general public in due course as was previously done with Mandela's Gold.
Uses and cultural aspects
It has been reported that the abakwaMthethwa clan in KwaZulu-Natal use the strained decoctions from the inflorence to treat inflamed glands and venereal diseases. The seeds are also used in the Cape to sour milk. Delphinidin-3-rutinoside (used for colour) has been isolated from the petals and proanthoncyanidin polymers (flavonoids, antioxidants) from the leaves. Strelitzia reginae is widely used in landscaping as an architectural plant and focal point.
Growing Strelitzia reginae
Strelitiza reginae can be propagated from seed and divisions. Hand pollination can be carried out as described by Notten (2002). Seed propagation is discussed in an article by Winter & Xaba (2011). Once seed has germinated, it is important to pot seedlings in a well drained fertile medium and to see that they are eventually adapted to a position in full sun. We have had great success with the following potting medium for strelitzias: 2 parts loam, 2 parts sand, 3 parts 12 cm bark, 3 parts compost and 1/2 part bone meal, and 1 part Bounce back® or 1 part 3.1.5 fertiliser. We feed our plants alternatively in May and November with a mixture of (a) 1 part superphosphates, 1 part 3.1.5, 2 parts Bounce back® and 2 parts bone meal or (b) compost. Compost or the mixture is generously scattered around the root area and watered in over a period of time. At Kirstenbosch potting/reporting, transplanting and dividing plants happens in autumn. This allows the plant to focus its energy on recovering rather than flowering. Mature plants will normally flower due to stress when divided or transplanted, an inbuilt survival mechanism. Flower stalks can be cut to allow quicker recovery. When dividing mature plants it is important to have a minimum 60 cm clump diameter, so that recovery is faster, more or less two to three years maximum, to full bloom again.
References and further reading
- Dyer, R.A. 1977. Strelitzia of the Eastern Cape. The Eastern Cape Naturalist. (61): 10 - 12.
- Hutchings, A., Scott, A.H., Lewis, G. & Cunningham, A.B. 1996. Zulu medicinal plants: an inventory. University of Natal Press, Pietermaritzburg.
- Notten, A. 2002. Strelitzia reginae Aiton 'Mandela's Gold' 9from the SANBI's PlantzAfrika web-site http://www.plantzafrica.com/plantqrs/strelitregmandelagold.htm)
- Pooley, E. 1998. A field guide to wild flowers of KwaZulu-Natal and the Eastern Region. Natal Flora Publications Trust, Durban.
- 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.
- Van Jaarsveld, E. 2008. Strelitzia reginae Banks ex Aiton subsp. mzimvubuensis Van Jaarsv. (from the SANBI's PlantzAfrika web-site ). http://www.plantzafrica.com/plantqrs/strelitzregmzimvu.htm
- Winter, J. & P. Xaba 2011. Strelitzia juncea Link. (from the SANBI's PlantzAfrika web-site) http://www.plantzafrica.com/plantqrs/strelitzjun.htm
Four other Strelitzia species occur in South
Africa namely Strelitzia juncea,
S. nicolai, S. caudata and S. alba.