Ledebouria concolor (Baker) Jessop.
Common names: Karoo African hyacinth
A large and handsome, African hyacinth, with bright green leaves and stout semi-erect, dense flower spikes, that makes a fine pot plant. This attractive bulbous species occurs in the Eastern Cape Province of South Africa, where it prefers semi-arid vegetation types.
Plants gregarious, forming clusters of few to several large bulbs, 60–120 mm in diameter. The bulbs are semi-epigeal (partly exposed above the ground) and covered with pale brown, papery sheaths.
The unspotted and bright green leaves, 125 × 40 mm, are held in a horizontal to spreading orientation; the wavy margins and rounded leaf tip, make them easy to recognize.
Multiple, unbranched inflorescences, 2–3 per bulb, are produced mostly in early summer (October–November), but can be rain dependent and flowers can be found throughout summer (October to March in South Africa). The stout, green peduncle (main stalk) spreads horizontally at the base, with the scape (part of stalk which bears flowers) erect. Numerous, small, green- and white-striped florets (small flowers), are held in a neatly arranged manner along the scape. The individual florets are attached to the peduncle by a small, green pedicel (flower stalk). The florets are held in a nodding fashion (facing downward) with whitish stamens protruding from the mouth of the floret, each topped with small, yellow anthers. The green- and white-striped tepals (petals and sepals), are reflexed in their upper third and acute (pointed) at the tips. Post flowering, small green capsules are produced, which split open to release the dark brown, wrinkled seeds.
Ledebouria concolor is listed as Least Concern (LC) in the Red List of South African plants. This species is abundant and not faced with significant threats in its natural habitat.
Distribution and habitat
The Karoo African hyacinth occurs in the Eastern Cape Province of South Africa, mostly around Port Elizabeth, and is also recorded from the Transkei region in the same province.
Derivation of name and historical aspects
The genus Ledebouria is named in honour of the German-Estonian botanist, Professor Carl Friedrich von Ledebour (1785–1851). The species name concolor, is Latin and made up of two parts; con, meaning ‘same’, and -color which means ‘colour’. The name is presumably in reference to the colour of the leaves being the same on both upper and lower surfaces, although this was not specified by Baker when he first applied the name.
This species was first named by J.G. Baker in 1870 as Scilla concolor. It was only placed into the genus Ledebouria 100 years later in 1970, by J.P. Jessop during his revision of the genus.
The genus Ledebouria is distributed across Africa, India and Madagascar, with the centre of species diversity in the eastern parts of southern Africa. South Africa has 42 species of Ledebouria.
This species is most likely to be confused with Ledebouria venteri, due to the size of the plants, as well as the mid-green and unspotted leaves and the semi-epigeal bulbs. However, these two species can be distinguished by several characters as follows:
Distribution: L. venteri occurs further west, from the Baviaanskloof to the Gouritz River.
Morphology: L. venteri has more glaucous, (bluish) green coloured leaves, with tapering to acute leaf tips.
Flowers: the inflorescence of L. venteri is flaccid, and the stamens are purple to violet, not green as in L. concolor.
Ledebouria concolor is a component of semi-arid vegetation types. It occurs out in the open in full sun, but is also often found in semi-shade, under bushes and trees. The large bulbs store water which enable it to survive for extended periods with little rain. Rainfall in these areas may fall at any time of the year, although the active growing season for this species, is summer. The flowers are cup-shaped with the stamens exerted and probably pollinated by many different visiting insects.
No specific references exist in the literature of this species being used by people. The genus Ledebouria as a whole has been used medicinally in Africa for purposes including pregnancy, diarrhoea, influenza, backache, skin irritations, wound treatment as well as lumbago. The genus is also reported as being poisonous, although it is also reported that Bushmen eat the bulbs of certain other species (L. apertiflora and L. revoluta).
Growing Ledebouria concolor
Ledebouria concolor is easy to maintain in cultivation. It should be treated like a succulent plant and be protected from excessive wetness for prolonged periods. Summer watering should be in the form of heavy watering, followed by a long period of drying, approximately once or twice per month. During the dry, winter, dormant phase, the plants should only be watered very lightly once a month. This species is suited to being grown outdoors in warm dry climates that will support it. Bulbs can be used in succulent rockeries and arid gardens, where the plants cannot be overgrown by other vegetation. For best effect, they should be planted in small groups clustered together to maximise the effect of the flowers. They prefer a gravelly, well-drained, sandy soil and can withstand full sun or semi-shade. In wetter climates, they should be maintained under cover, in containers, using a gravel-rich, sandy loam as a growth medium, with small amounts of compost or cattle manure added. Growing the plants in full sun will ensure an attractive and compact growth habit, although they can grow in semi-shade. During the dry, winter, dormancy period, the pots should be moved out of the rain and placed in a dry, cool area with adequate air movement. Watering can commence towards the end of winter at the onset of warmer weather (August–September in South Africa).
Propagation from seed is the best method of producing more plants; the seed must be sown fresh. Sow seeds immediately (do not store them) in spring or summer, in shallow seed trays filled with the sifted potting mixture mentioned above. Sow seed on a firmly tamped surface and lightly cover with the same mixture approximately 2 mm deep. The trays should be kept in a bright, warm position out of direct sunlight and kept damp until germination has commenced. Seedlings can be planted out as soon as they are large enough to handle. Flowering size bulbs can be attained after 3 years from germination.
- Dictionary of botanical epithets. http://www.winternet.com/~chuckg/dictionary.html
- Hankey, A. 2011. Ledebouria Roth. PlantZAfrica. Internet 5 pp. http://pza.sanbi.org/ledebouria-genus
- Venter, S. 1993. A revision of the genus Ledebouria Roth (Hyacinthaceae) in South Africa. Unpublished M.Sc. thesis, University of Natal, Pietermaritzburg.
- Venter, S. 2008. Synopsis of the genus Ledebouria Roth (Hyacinthaceae) in South Africa. Herbertia 62
Walter Sisulu National Botanical Garden
Plant Type: Bulb
SA Distribution: Eastern Cape
Soil type: Sandy, Loam
Flowering season: Spring, Early Summer
PH: Acid, Neutral
Flower colour: Green, White
Aspect: Full Sun, Afternoon Sun (Semi Shade)
Gardening skill: Easy