Dracaena transvaalensis Baker
Common names: Wolkberg dragon tree (Engl.); Wolkbergdrakeboom, dolomiet-drakeboom (Afr.)
SA Tree No: 30.10
Dracaena transvaalensis is a medium-sized, aloe-like tree. It has large, elongated, ascending leaves arranged in central rosettes. The large inflorescence with showy, yellowish green to cream-coloured flowers, appears in mid-summer at the branch ends, opening only during the night.
Small, sparsely fork-branched (dichotomously), ascending, semi-succulent trees, growing up to 6 m high, bearing 1 to 5 heads (leaves crowded at the ends).
Roots succulent, orange-brown.
Main branch is stout, up to 450 mm in diameter at the base. Bark corky at the base, grey-white, longitudinally fissured. The leaf-bearing branches are about 50–90 mm in diameter.
The elongated, strap-shaped leaves (ensiform), which clasp the stem at the base (partially amplexicaul), are carried in elongated central rosettes at the branch ends for up to 1 000 mm. These are firm, leathery, dark green and ascending 700–930 mm long and 450–550 mm broad. The lower surface is rounded at the base with a prominent midrib about 10 mm in diameter and becoming narrower towards the leaf end. The leaf margin is entire. The leaf tip is long and drawn out (acuminate). The older leaves are deciduous from the base resulting in concentric, zebra-like markings on the upper stems below the leaves.
The inflorescence is a pyramidal panicle, up to 1 800 mm tall and about 800 mm in diameter, carried on the stem ends. The stalk of the inflorescence is covered with leaf-like bracts, becoming gradually shorter upwards. The racemes are up to 100–180 mm long and laxly arranged, ascending spreading, with yellowish green, tubular buds 50–55 mm long. The flowers are ascending spreading, carried 1–3 together, greenish white, the 6 petals free for 20 mm at the ends, and 2 mm in diameter, becoming recurved, with stamens inserted in the upper half of the petals and the cream-coloured anthers protruding. The base of the flower is slightly swollen, about 4 mm in diameter and on short pedicels 5–7 mm long. The flowers only open at night, and are sweetly fragrant. The stigma (female receptive part) becomes exposed for 23 mm. The female part (ovary) is greenish, club-shaped, 9 mm long, the tip 3-lobed, blunt and 3.5 mm in diameter.
The fruit is a green, fleshy, rounded berry, up to 2-seeded), about 8–15 mm in diameter, becoming orange when ripe, and with a rough tuberculate surface.
Flowering time: mid-summer (December–January in the southern hemisphere).
Because of its restricted distribution and small numbers, Dracaena transvaalensis is recorded as R (Rare). in the Red List of South African plant species (Raimondo et al. 2009).
Distribution and habitat
Dracaena transvaalensis is only recorded from the dolomite region in the Olifants River Valley near Penge, in the Limpopo Province, and the adjacent Wolkberg. Near Penge, the plants grow in dry Poung Dolomite Mountain Bushveld, which forms part of the Central Mountain Bushveld (Mucina et al. 2005). They grow among dolomite rocks on steep slopes and kloofs, often in full sun or light shade. They share their habitat with other bushveld plants such as Croton gratissimus, Aloe marlothii, Ruttya ovata, Crassula expansa subsp. fragilis, Euphorbia excelsa, E. grandialata and E. lydenburgensis, Plectranthus dolomiticus, P. montanus and P. hadiensis, Dombeya autumnalis, Encephalartos inopinus, Sterculia rogersii, Gasteria batesiana and Portulacaria afra. The climate is hot in summer, and the frost, if it occurs in winter, is very light. Rainfall in the region is about 400–650 mm per annum, and it is mainly experienced in summer.
Derivation of name and historical aspects
The specific Latin epithet transvaalensis refers to the ‘Transvaal’, the previously name for the province (now including the Limpopo, North West, Gauteng and Mpumalanga).
D. transvaalensis was named by British botanist, J.G. Baker in 1904 in the Bulletin de L’Herbier Boissier (Serie 2, 4: 1001), from plants collected by the Swiss, Henri-Alexandre Junod (1863–1934), a missionary, anthropologist and naturalist, who collected it from where he was stationed near Shiluvane in the Limpopo Province (Gunn & Codd 1980). The genus Junodia Pax was named in his honour as well as other plant species.
About 60 species are recorded mainly from Africa and surrounding territory. The largest is the impressive dragon tree, D. draco from the Canary Islands, today cultivated in warmer parts of the world.
Dracaena transvaalensis is closely related to the large-leaved dragon tree (D. aletriformis), which is commonly recorded from the forested eastern part of South Africa. From this species, it is immediately distinguished by its larger size (D. aletriformis not a tree, and rarely branched) and fruit which has a smooth surface. The bark of D. aletriformis is also not corky. Only three species have been recorded from South Africa, D. aletriformis, D. mannii and D. transvaalensis. D. mannii is a large, much-branched shrub or small tree (can grow to 12 m tall) from the Maputaland Coastal Belt (Indian Ocean Coastal Belt).
Dracaena transvaalensis is pollinated by moths at night, when its sweetly scented flowers open. The orange berries are relished by starlings and other frugatory birds. Seeds ripen in autumn coinciding with the rainy season.
The plant has horticultural potential, but has no medicinal or other recorded uses.
Growing Dracaena transvaalensis
Dracaena transvaalensis is an ornamental, semi-succulent species, of medium growth rate, which is best grown in dry bushveld gardens (Van Jaarsveld 2010). It is best grown in full sun but will tolerate light shade. It is easily propagated by side branches or seed. If grown in shady conditions, the leaves tend to be larger. Plants prefer a soil which is alkaline but will tolerate acidic soils. This plant is also suited for containers. After the baobab tree, D. transvaalensis was one of the first plants planted in the Botanical Society Conservatory at Kirstenbosch in 1996. These have grown considerably into many-headed, small trees, some which have reached 6 m (January 2015). Plants flower annually in summer, when their sweet fragrance becomes very prominent during the night, attracting local moths for its pollination. The plants also produce numerous berries in autumn, relished almost immediately by local the Cape Bulbul (Pycnonotus capensis). A Cape Robin-Chat (Cossypha caffra) has also nested in the leaves of its lower branches.
The Wolkberg dragon tree grows well in other parts of the world or similar climates where frost is absent or light. Plants should reach flowering size within about eight to ten years. To obtain pure seed, it is best to cross-pollinate from two individuals. This can be accomplished with a sharpened match stick by transferring the pollen from a genetically different plant to the stigma of another, thereby ensuring that the species breeds true.
Dracaena transvaalensis seed should be sown preferably fresh during the warmer months, in a shady position. Cover with a thin layer of sand, and keep moist. Germination is usually within three weeks. Seedlings grow slowly and are best planted out when large enough to handle.
Propagation from stem cuttings is best undertaken in spring. Allow the cutting to form a heel, by placing it on a dry window sill for a week. The wound can be treated with sulphur to deter germinating fungal spores. Cuttings are best rooted in containers in a well-drained medium, such as sand. Once rooted, they can be planted in individual containers and kept until well established. Best to feed plants with an organic product (compost or any other liquid fertilizer). Dracaena transvaalensis needs watering during summer, and watering should be reduced in winter.
- Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of southern Africa , edn 3. Struik, Cape Town.
- Gunn, M. & Codd, L.E. 1980. Botanical exploration of southern Africa. Balkema, Cape town.
- Mucina, L. & Rutherford, M.C. 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria.
- 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.J. 2010. Water wise gardening. Struik, Cape Town.
- Bos, J.J. 1992. Dracaenaceae. In O.A. Leistner, Flora of southern Africa Vol 5, 3: 1–4). National Botanical Institute, Pretoria.
Ernst van Jaarsveld
Kirstenbosch National Botanical Garden
Plant Type: Shrub, Succulent, Tree
SA Distribution: Limpopo
Soil type: Sandy
Flowering season: Autumn
Flower colour: Green, Cream
Aspect: Full Sun, Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Easy