Ledebouria atrobrunnea S.Venter.
Common names: dark brown African hyacinth (Eng.)
This dwarf, range-restricted African hyacinth with erect leaves and characteristic dark brown persistent leaf bases, is an interesting and attractive plant from North West and Limpopo Provinces of South Africa.
Usually solitary, dwarf, bulbous plants, 80–120 mm high, with greyish milky green, unspotted, narrowly triangular, deciduous leaves, which are held erect and are often marginally crinkled toward the base. Solitary inflorescences are usually produced in spring and early summer (October to December), semi-erect to spreading slightly outwards from between the leaves, bearing numerous small, whitish to pale purple flowers, with a green median stripe. The individual florets (small flowers) are comprised of 6, strongly recurved, strap-shaped tepals (petals). Flowers are soon followed by green, swollen, 3-chambered fruits, which split to reveal small, glossy, wrinkled, blackish brown seeds.
This species is most easily confused with Ledebouria leptophylla from which it differs by the erect, narrowly triangular, milky green leaves, as opposed to spreading, greyish green, linear leaves in L. leptophylla. Furthermore, L. atrobrunnea is range restricted and usually has persistent, dark brown bulb sheaths and persistent leaf bases clustered around the bulb, whereas L. leptophylla tends to have a more naked bulb without dark brown bulb sheaths.
This species is red listed as Least Concern (LC) which means it is not considered to be threatened in its natural habitat.
Distribution and habitat
This species occurs over a limited range in North West and Limpopo Provinces of South Africa. The species has been recorded from near Kroondal near Rustenburg in North West and near Northam in Limpopo; these locations are approx. 60 km apart and it is likely that the species also occurs at other isolated locations in the general area. It is usually found in woodland and wooded grassland amongst rocky outcrops or in open grassland.
Derivation of name and historical aspects
This species was first named by S. Venter in his revision of the genus in 1998. The genus is named in honour of the German-Estonian botanist, Professor Carl Friedrich von Ledebour (1785–1851). The specific name atro-, means ‘dark’ and -brunnea, means ‘brown’, in reference to the characteristic dark brown, hard, persistent, dry bulbs sheaths and persistent dead leaf bases, which clothe the bulb, and can also be seen protruding above the soil surface.
South Africa has 58 species of Ledebouria, with several more species occurring across southern, western, East and northeast Africa and into India.
This species is recorded as growing in soils derived from Magaliesberg quartzite and chert rich dolomite. Porcupines are known to dig out and eat the bulbs of several species of Ledebouria and large ungulates have been observed to browse the leaves. The dwarf habit and narrow, grass-like leaves may enable the plants to escape being browsed by herbivores. The narrow leaves may effectively camouflage the plants amongst the grass with which it occurs, and may also aid in eluding insects which are likely to eat the leaves. The vegetation where the species occurs, is prone to grass fires during the dry winter season, although there is no indication that this species is specifically respondent or dependent on fire as part of its ecology; it would presumably benefit from the removal of accumulated dead grass that has builds up over a couple of years. The species would survive the fires in winter because it being deciduous and the bulbs being protected underground.
Ledebouria atrobrunnea possesses typical Ledebouria-type flowers which are open and cup-shaped with their pollen openly presented, which suggests that the flowers are opportunistically pollinated by most visiting insects. The flowers, which have not been recorded as being scented, can be seen being visited by various different insects, including honey bees and solitary bees. The inflorescences are mostly erect to spreading at first, becoming more flaccid (floppy) with age; this may have something to do with optimizing visibility of the flowers to attract pollinators. The seed is small black and pear-shaped with a glossy wrinkled surface. Venter (1993) suggests that Ledebouria seeds may be distributed by water wash, which is likely after heavy thunderstorms, which are frequent across the areas where the species occurs.
There are no documented uses or cultural aspect for Ledebouria atrobrunnea, except perhaps a few plant collectors who would grow the species as a curiosity in a collection.
The genus Ledebouria, as a whole, is cited as having been used medicinally for purposes including pregnancy, diarrhoea, influenza, backache, skin irritations, wound treatment as well as lumbago. Although there are no published reports of this species being poisonous, it is likely to be, and should therefore be regarded with caution. The genus generally is reported as being poisonous, although it is also reported that Bushmen ate the bulbs of certain species, including L. revoluta and L. apertiflora. However, these may have been cooked or prepared in some manner to destroy the toxins, which is not specifically documented. Despite the fact that some large ungulates do browse the leaves, the entire genus should be regarded as being poisonous as a precaution.
Growing Ledebouria atrobrunnea
The dark brown African hyacinth is very easily cultivated, although they are best suited to containers because of their dwarf habit. They are best grown outdoors in terracotta pots in full sun to semi-shade, in a warm temperate climate.
Plant the bulbs in sandy loam soil or a well-drained, sandy, mineral-rich potting medium, with sifted, well-aged kraal (cattle) manure or mature compost added. Watering should be done mainly in the summer growing season. The pots should be dried out during the dry winter rest period. The plants prefer a warm summer growing season and can withstand cold temperatures in winter, providing the soil is kept completely dry and the plants are dormant.
Pots should be moved out of any rain during the dormant winter season, and kept in a cool dry position with good air movement. Summer growth is initiated by the onset of warmer temperatures (August to October). Watering can commence at this stage and thereafter.
Adult plants can become afflicted with scale insect and mealy bug (including on the roots) especially if the cultural conditions are not ideal. Both of these maladies can be managed with a systemic insecticide. Ants will often bring and spread such infestations and, as such, it is best to manage ant populations where the plants are housed.
Ledebouria atrobrunnea is easily cultivated from fresh seed (seed cannot be stored for longer than 1 year) sown in spring or summer. Sow seed on a finely sifted surface in the adult potting medium, in pots or trays. Press seeds lightly into the soil and cover with a fine layer of approx. 2–3 mm of the sifted medium. Water weekly and keep in a warm and protected position out of direct sunlight. Seeds germinate within 2–3weeks, after which watering should be reduced. Bulblets can be allowed to remain in their natal container for the first year, after which they can be planted out into individual or community pots. Flowering can begin at 2–3years from seed.
- Craib, C. & Brown, L. 1998. Ledebouria atrobrunnea S.Venter, a new species from the Western Magaliesberg in South Africa’s North-West Province. Herbertia 53: 59–63.
- Hankey, A.J. 2019. Proposed English common names for African hyacinths (genus Ledebouria). Plantlife SA, Vol 47:7 https://plantlifesouthafrica.blogspot.com/
- Hankey, A.J. & Venter, S. 2002. Ecology, cultivation and conservation status of Ledebouria atrobrunnea. Plantlife 01/2002; 26: 32–34.
- Jessop, J.P. 1970. Studies in the bulbous Liliaceae in South Africa: 1. Scilla, Schizocarpus and Ledebouria. Journal of South African Botany 36(4): 233–266.
- Venter, S. 2008. Synopsis of the genus Ledebouria Roth (Hyacinthaceae) in South Africa. Herbertia 62: 85-155
- Venter, S. & Edwards, T.J., 1998. A revision of the genus Ledebouria (Hyacinthaceae) in South Africa. 1. Two new species. Bothalia 28: 15–17.
- Wikipedia. Carl Friedrich von Ledebour. http://en.wikipedia.org/wiki/Carl_Friedrich_von_Ledebour. Accessed 6 November 2018.
Walter Sisulu National Botanical Garden
Plant Type: Bulb
SA Distribution: Limpopo, North West
Soil type: Sandy, Loam
Flowering season: Spring, Early Summer
PH: Acid, Neutral
Flower colour: Green, Purple, White
Aspect: Full Sun
Gardening skill: Average