Although it is dormant during summer and autumn and has a very narrow distribution area, this extraordinary, beautiful member of the Hyacinth family is a must see for every plant lover. The striking red or yellow flowers light up the veld when it flowers in spring.
Daubenya aurea is a flat-growing, bulbous geophyte up to 50 mm tall. It produces two spreading leaves up to 110 mm long and 60 mm wide, which are ovate and narrowing to a broad tip. Tubular flowers are red or yellow, and nearly sessile, arranged in a cluster between the two leaves. Outer flowers are irregular with three sub-equal spoon-shaped segments longer than the tube and three small spear-shaped inner segments. Whilst, the outer segments are longer than the stamens, the stamens are longer than the inner flowers. Daubenya aurea flowers mainly in September, but has also been recorded flowering in July and August.
The current Red List status of Daubenya aurea is Vulnerable (VU) and it faces a high risk of extinction in the wild. Rapid, recent expansion of cultivation of low-lying clay flats is severely threatening this highly range-restricted species. Although it has not been identified as a negative impact, field observations indicate that plants are subjected to heavy grazing and trampling. The Indigenous Bulb Association of South Africa (IBSA) monitors this plant every year ( http://www.pacificbulbsociety.org ).
Distribution and habitat
Daubenya aurea is found only high in the Roggeveld Mountains, in suitable habitats between Sutherland and Middelpos in the Northern Cape Province of South Africa. The species occurs on flat, low-lying dolerite-derived clay soils, which can become damp during the rainy season. Daubenya aurea is frost tolerant and is often covered by snow in its natural environment. It appears that low temperatures induce better flowering.
Derivation of name and historical aspects
The genus was described in 1835 by British botanist John Lindley and named in honour of his compatriot, Charles Giles Bridle Daubeny (1795–1867), who explored the horticultural potential of the species at the Oxford Botanical Garden.
The specific epithet, aureus, refers to the golden yellow flowering form of this species.
Daubenya was once thought to consist of only one species but was revised in 2002 by Manning et al. to include eight species, namely: D. alba , D. aurea, D. capensis, D. comata, D. marginata, D. namaquensis, D. stylosa and D. zeyheri.
Daubenya aurea is pollinated by monkey beetles. The enlarged outer petals of the flowers give the inflorescence the overall appearance of a daisy, which attract these beetles.
Uses and cultural aspects
Even though Daubenya aurea has no cultural or medicinal use, it is used extensively in the horticultural trade. Bulbs and seed are available freely on the internet through various plant traders.
Growing Daubenya aurea
Daubenya aurea is best propagated from seed, as the bulbs rarely split or produce offsets. Store seeds in a warm place and sow it in a compost mix containing peat, perlite and coarse grit. This species needs well-drained fertile soil and can be fertilised with organic fertiliser once a month. Germination usually takes about 6 weeks if trays are put outside in a shady place. Once germinated, plants can be potted anytime during their dormant period. Plants should ideally be watered with rainwater, which is free of lime. Stop watering and leave them completely dry as soon as the leaves start to die back before the dormant period. Expose plants to sunlight after the dormant period. Many plants will flower in their third season of growth.
Even though the faded flowers of Daubenya aurea are prone to botrytis, Daubenya aurea seem to be largely free of serious pest or disease problems. The flowers must be removed as soon as they start to fade to reduce the risk of infection.
References and further reading
- Goldblatt, P., Bernhardt, P., Manning, J.C. 1998. Pollination of Petaloid Geophytes by Monkey Beetles (Scarabaeidae: Rutelinae: Hopliini) in Southern Africa . Annals of the Missouri Botanical Garden 85: 215–230 .
- http://www.pacificbulbsociety.org . Roggeveld two . Accessed: 08/10/2013.
- http://rareplants.co.uk . Daubenya. Accessed: 14/10/2013.
- http://www.simplyindigenous.co.za . Container landscaping with indigenous bulbs. Accessed: 16/10/2013.
- http://www.srgc.org.uk/wisley/wisleylog.html. 2007. Log 9 . Daubenya . Accessed : 21/10/2013.
- Manning, J. 2001. South Africa's jewels of the desert: A reappraisal of the genus Daubenya (Hyacinthaceae). Herbertia 56: 61–66.
- Manning, J., Goldblatt, P.E. & Snijman, D. 2002. The colour encyclopaedia of Cape bulbs . Timber Press, Oregon.
- 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 Botanical Institute, Pretoria.
- http://redlist.sanbi.org. Accessed: 02/10/2013.
- Van der Merwe, H. 2010. Wild flowers of the Roggeveld and Tanqua . Published by author.
Baloyi Cynthia Mikateko & Marinda Koekemoer
Pretoria National Herbarium