This is a dwarf, summer-deciduous succulent with drooping, string-like leaves and ascending yellow flowers from cliffs in northern Namaqualand and the Richtersveld. It is one of many summer-deciduous dwarf Bulbine species in the winter-rainfall region of the Northern and Western Cape provinces.
A dwarf, stemless summer-deciduous, soft, frail geophyte, solitary or dividing to form small dense clusters. The tubers are oblong, 30 × 15 mm, with radiating lobes which taper into roots. The softly succulent leaves (1 or 2) are light green, pendent (hanging down), 60–150 mm long, linear, subterete (± cylindrical), up to 2–5 mm in diameter, bearing striations (longitudinal lines). During dry conditions the leaves become slightly channelled. The inflorescence is solitary, ascending, 80–180 mm long and up to 4-flowered with flower stalks (pedicels) up to 25 mm long. The flowers are yellow to yellowish orange, about 18 mm in diameter, the six tepals are spreading. The stamens are about 5 mm long with bearded filaments. The ovary is rounded, 1.5–2.0 mm in diameter with an erect style about 5 mm long. The fruiting capsule is about 3 mm in diameter, with blackish brown seed up to 1,7 mm long.
Flowering occurs during spring.
Although it was described as critically rare in the Red List of South African Plants (Raimondo 2009), it was recently found at three or more sites. The plants were only known from south-facing cliffs of the Rosyntjieberg (Richtersveld). However, recent finds in the Gannakouriep, Paradyskloof and also the Skaaprivierspoort (west of Springbok) show that, although restricted to its cliff face habitat, it is fairly widespread. The plants are well protected by their cliff face habitat, as the crevices in which they grow are difficult to reach.
Distribution and habitat
Bulbine pendens has been recorded from the Richtersveld and northern Namaqualand in the Northern Cape Province of South Africa. In the Richtersveld it is still only known from within the borders of the Richtersveld National Park. Here it has been recorded from the Paradyskloof, Gannakouriep as well as the Rosyntjieberg. The author also recorded plants from more than 100 km south, along the Skaaprivierspoort northwest of Springbok. The Richtersveld is known for its many endemic plants, and as a rich centre of plant endemism (Van Wyk & Smith 2001).
Bulbine pendens grows on vertical cliffs of narrow shady kloofs, mainly southern aspects, at about 300–800 m altitude. The plants grow firmly rooted in crevices. Temperature is high in summer with cool winters (frost absent). Rainfall occurs mainly during winter, ranging from 75–150 mm per annum (thundershowers or cyclonic winter-rain).
Plants have been recorded from the Rosyntjieberg Succulent Shrubland as well as the Central Richtersveld Mountain Shrubland of the Succulent Karoo Biome (Mucina & Rutherford 2006).
On the Rosyntjieberg the plants were found growing in association with other succulents such as Aloe meyeri, Conophytum taylorianum subsp. rosynense, Cyrtanthus herrei, Trachyandra aridimontana and Tylecodon ellaphieae.
The geology consists of light-coloured quartzitic sandstone. The soil is acidic.
Derivation of name and historical aspects
Bulbine pendens was named by G. Williamson and S. Baijnath in the South African Journal of Botany in 1995 from plants collected by G. Williamson growing on cliffs on the lower slopes of the Oemsberg. The specific epithet ‘pendens' pertains to the pendent leaves.
The tuber and succulent leaves are an adaptation to its dry habitat. During the dry summers the plant becomes deciduous. Its growing season starts during autumn when new leaves appear, and it continues during the winter season when rainfall is expected. The area is also subject to fog settling on the cliffs and mountain slopes which ensures additional moisture. The small lines on the leaves are translucent and act as windows through which light can penetrate deeply.
The open flowers suggest pollination by insects. The seeds are wind dispersed.
Uses and cultural aspects
The small plants are of no known cultural importance but are treasured by the connoisseur succulent plant enthusiast.
Growing Bulbine pendens
The bootlace bulbine requires specific growing conditions. It grows best in small containers in a greenhouse under controlled conditions. The best container is clay or ceramic. Make use of a sandy, slightly acidic soil mixture. It is best kept in a partial shady position and kept moist from late autumn to spring, but do not overwater. Avoid watering during the dry summer months when the plant becomes dormant.
Bulbine pendens is best propagated from seed sown during late summer or winter. Sow in a shallow tray with a gravel mixture and cover lightly with sand. Keep moist, and germination takes place within three weeks. The young plants grow fairly fast. Plants react well to a mild organic fertiliser which can be added to the water.
References and further reading
- Mucina, L. & Rutherford, M.C. (eds) 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria.
- Raimondo, D. 2009. Bulbine pendens in D. Raimondo, L. von Staden, W. Foden, J.E. Victor, N.A. Helm, R.C. Turner, D.A. Kamundi, & P.A. Manyama (eds). Red List of South African plants 2009. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
- Williamson, G. & Baijnath H. 1995. Three new Bulbine Wolf (Asphodelaceae) [Author: add ‘species'?']from the Richtersveld and the southern Namib Desert. South African Journal of Botany 61,6: 312–318.
- Van Wyk, A.E. & Smith, G.F.. 2001. Regions of floristic endemism in southern Africa: a review with emphasis on succulents . Umdaus Press, Hatfield, South Africa.
Ernst van Jaarsveld
Kirstenbosch National Botanical Garden