Calobota cytisoides (P.J.Bergius) Eckl. & Zeyh. (= Lebeckia cytisoides (P.J.Bergius) Thunb.)
Common names: bush ganna (Eng.), ganna, geelertjiebos, kristinabos (Afr.)
Calobota cytisoides is an attractive, yellow-flowered shrub which is widespread in the Western Cape Province of South Africa.
Erect, multi-stemmed, unarmed shrub up to 2 m in height. Branches green; young branches sericeous (silky); older branches sericeous to pilose with brown bark. Leaves alternate, digitately trifoliolate (with 3 leaflets arranged like fingers on a hand) to rarely 5-foliolate; leaflets elliptic to oblanceolate, sericeous. Inflorescence racemose with 7 to 25 flowers; flowers large, bright yellow, sweetly scented. Calyx without hairs. Pods linear, terete, ±5- to 18-seeded, without hairs, dehiscent. Seeds oblong-reniform (kidney-shaped), mature seeds light brown, surface smooth.
Flowering time: Mainly flowering and fruiting in late winter to spring (June to November).
Least Concern (LC; Raimondo et al. 2009).
Distribution and habitat
Calobota cytisoides is a common and widely distributed species. It can be found from Oudtshoorn through to Montagu and Worcester, and northwards to around Nieuwoudtville.
Derivation of name and historical aspects
The genus Calobota Eckl. & Zeyh. was recently reinstated to accommodate 16 species previously placed in Lebeckia Thunb. and Spartidium Pomel (Boatwright et al. 2009). This followed studies based on DNA sequence data and morphology which revealed that the genus Lebeckia is not a natural group, i.e. it is polyphyletic (descended from more than one ancestral group), and that a division into three genera, one of which is Calobota, was necessary (Boatwright et al. 2008; Boatwright et al. 2009). The specific epithet "cytisoides" means Cytisus -like and refers to the resemblance of this species to those of the genus Cytisus L. in its large yellow flowers and green stems.
Calobota cytisoides has a more southern distribution than the closely related C. sericea (Thunb.) Boatwr. & B.-E.van Wyk and has been collected at altitudes of between 20 m and 1000 m in fynbos and renosterveld vegetation on sandstone, shale, well-drained sand and clay. It is often found on western, southern or south-western slopes, along rivers or in riverbeds and also along disturbed roadsides. Rebelo et al. (2006) and Mucina et al. (2006) list this species as an important component of Shale Fynbos, Shale Renosterveld and Rainshadow Valley Karoo.
The flowers of Calobota cytisoides have a very sweet scent. The nectar of this species and the rest of Calobota is generally sucrose-rich (Van Wyk 1993), which is typical of most bee-pollinated legumes. The potential pollinators of some of the Cape genera of the Crotalarieae were studied by Gess & Gess (1994, 2003). They found that the flowers of Calobota species were visited by solitary aculeate Hymenoptera (bees or wasps), specifically Masarinae and Megachilinae of the tribes Megachilini and Anthidiini and also some species of Xylocopinae.
There is no recorded ethnobotanical use for Calobota cytisoides, but its close relative C. sericea is documented as being used as a remedy for colds by the Nama people (Watt & Breyer-Brandwijk 1962).
Growing Calobota cytisoides
Plants of C. cytisoides can reach a height of up to 2 m, and with the striking, sweet-scented yellow flowers should make a bold garden subject.
Specific details on the cultivation of C. cytisoides are unavailable, but conditions will likely be the same as for other fynbos legumes that are presently being cultivated, e.g. Aspalathus L., Liparia L. and Podalyria Willd., which are largely grown in well-drained soil and need water during winter in summer rainfall areas. Seeds of Calobota cytisoides can be purchased at selected seed suppliers and germinate readily after scarification.
- Boatwright, J.S., Le Roux, M.M., Wink, M., Morozova, T. & Van Wyk, B.-E. 2008. Phylogenetic relationships of tribe Crotalarieae (Fabaceae) inferred from DNA sequences and morphology. Systematic Botany 33: 752-761.
- Boatwright, J.S., Tilney, P.M. & Van Wyk, B.-E. 2009. The generic concept of Lebeckia (Crotalarieae, Fabaceae): Reinstatement of the genus Calobota and the new genus Wiborgiella. South African Journal of Botany 75: 546-556.
- Gess, S.K. & Gess, F.W. 1994. Potential pollinators of the Cape group of Crotalarieae (sensu Polhill) (Fabales: Papilionoideae), with implications for seed production in cultivated rooibos tea. African Entomology 2: 97-106.
- Gess, S.K. & Gess, F.W. 2003. A catalogue of flower visiting records for aculeate wasps and bees in the semi-arid to arid areas of southern Africa. Rhodes University Printing Unit, Grahamstown.
- Mucina, L., Jürgens, N., Le Roux, A., Rutherford, M.C., Schmiedel, U., Esler, K.J., Powrie, L.W., Desmet, P.G. & Milton, S.J. 2006. Succulent Karoo Biome. In L. Mucina and M. C. Rutherford (editors), The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19: 221-299. South African National Biodiversity Institute, Pretoria.
- Raimondo, D., L. von Staden, W. Foden, J. E. Victor, N. A. Helme, R. C. Turner, D. A. Kamundi, and P.A. Manyama (editors). 2009. Red List of South African plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
- Rebelo, A.G., Boucher, C., Helme, N., Mucina, L. & Rutherford, M.C. 2006. Fynbos Biome. In L. Mucina and M. C. Rutherford (editors), The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19: 53-219. South African National Biodiversity Institute, Pretoria.
- Van Wyk, B.-E. Nectar sugar composition in southern African Papilionoideae (Fabaceae). Biochemical Systematics and Ecology 21: 271-277.
- Watt, J.M. & Breyer-Brandwijk, M.G. 1962. The medicinal and poisonous plants of Southern and Eastern Africa, 2nd edition. Livingstone, London.
Plant Type: Shrub
SA Distribution: Northern Cape, Western Cape
Soil type: Sandy
Flowering season: Spring, Winter
Flower colour: Yellow
Aspect: Full Sun
Gardening skill: Challenging