Pelargonium betulinum (L.) L'Herit.
Common names: camphor-scented pelargonium, birch-leaved pelargonium (Eng.); kanferblaar, maagpynbossie, suurbos (Afr.)
Pelargonium betulinum is dazzling in full flower, deserving of a place in any garden.
It is a small, upright or sprawling bushy herbaceous shrublet with woody branches, growing 0.3-1.3 m tall in the wild but in cultivation usually reaching a height of around 0.5 - 0.75 m with an equal spread. The leaves are small, 1-3 cm long by 0.7-2.5 cm broad, oval or ovate in shape, and are carried on ±1-cm long petioles. The leaf blades are somewhat hard and leathery, are either almost hairless or covered in fine short hairs, and have a serrated margin of red-tipped teeth.
The flowers are large and attractive, making this plant very conspicuous when it is in flower. The inflorescence is umbel-like, usually consisting of three to four flowers, occasionally of up to six. Flower colour is variable, pink and purplish flowers being most commonly seen in the wild, and there is also a white form. All flowers have dark purplish streaks on the petals, particularly on the two upper petals. Pelargonium betulinum flowers during spring and summer, with a peak from August to October, and a few flowers appearing all summer until February.
Distribution and habitat
Pelargonium betulinum is confined to the coastal areas of the winter-rainfall region of South Africa, from Yzerfontein on the west coast to Knysna on the east coast of the Western Cape, where it grows on sandy dunes and flat areas. It is often found growing in association with Pelargonium cucullatum and hybrids of these two species are not uncommon.
Derivation of name and historical aspects
Pelargonium betulinum belongs in the Geraniaceae family, a large cosmopolitan family of approximately 11 genera and 800 species in subtropical and temperate regions of the world. There are approximately 270 species of Pelargonium which occur in south, east and north-east Africa, Asia, St Helena, Tristan da Cunha, Madagascar, Australia and New Zealand, most of which (±219 species) occur in southern Africa.
The genus Pelargonium gets is name from the resemblance of the shape of the fruit to the beak of a stork, pelargos in Greek, while the species name betulinum is derived from the resemblance of the leaves of this plant to those of European birches, Betula species. The Afrikaans common name kanferblaar, camphor leaf or camphor-scented pelargonium in English, is derived from the camphor-like scent released when the leaves are crushed. Its other name, maagpynbossie (direct translation: stomach-pain little bush or more sensibly: little bush for stomach pain), is also applied to Myrica quercifolia and refers to the use of these plants to relieve flatulence and pain in the stomach. It is also known by the name suurbos (sour bush) which most likely refers to the taste of the leaves.
The seed is adapted to wind-dispersal, is light in weight and has a feathered tail which is coiled into a spiral. After landing on the ground in suitably soft soil, the tail causes the seed to be twisted around so that it drills into the soil in a corkscrew fashion, thus securing itself, ready to germinate with the onset of the rainy weather in autumn.
The leaves of Pelargonium betulinum contain essential oils and are used medicinally for coughs and other chest troubles, where fresh leaves are placed in boiled water and the vapour from the steamed leaves is inhaled. The leaves are also known to be used in wound healing ointments. Since it also has the common name maagpynbossie, it would appear that it is also used in some regions to relieve stomach pain.
Growing Pelargonium betulinum
This species was probably first cultivated in Holland in around 1738, and was introduced to Britain by Francis Masson in 1786. It is a fast growing, showy, long-flowering but relatively short-lived (5 years) perennial that brings spring colour to the mixed border, the shrubbery, fynbos gardens, coastal gardens and beach-front gardens where it looks particularly striking when the white, pink and purple colour forms are planted together. It can be used like a bedding plant to create a dense band of colour for a border, or allowed to form a rounded bush of 3-5 plants grouped together. It also does very well in containers, and can be used in hanging baskets, tubs and window boxes.
Pelargonium betulinum requires full sun or semi-shade, and a neutral, well-drained sandy soil with ample compost (leaf mould), a recommended mix being 1 part loam : 2 parts sand : 2 parts compost, plus some granular fertiliser. The plants can be fed during the growing season with moderate amounts of granular fertilizer or a seaweed-based fertilizer. This species is wind- and drought-tolerant and need only be watered when the soil is dry. Healthier stronger plants will be produced if they are watered deeply less frequently, rather than being given light waterings every day. It can be considered hardy to a winter minimum of approximately -5oC / 23oF (USDA zone 9) but is not suitable for permanent outdoor cultivation in regions that experience prolonged periods below freezing. Bushes can be pruned after flowering and the removal of up to one third of the growth will rejuvenate the plant and improve flowering the following season.
Propagation is by cuttings or seed. This species is readily propagated from softwood and tip cuttings taken from healthy young growth in autumn (March to May). The cuttings should be left to dry in a cool spot for a few hours. The basal ends should be dipped in a rooting hormone, and inserted into a prepared hole made by a dibber or a nail to avoid damaging the ends. The cuttings should be rooted in a cold frame, in a well-drained medium, such as coarse river sand. The first watering should contain a fungicide or agricultural disinfectant — for example a.i. benomyl (Benlate)/copper oxychloride/captab (Kaptan)/didecyl dimethyl ammonium chloride (Sporekill)) — after which the cuttings should be watered regularly but not excessively. Rooting should occur in 4 to 8 weeks and a weaning period of 1 week is recommended. The newly rooted cuttings can be fed with a seaweed-based fertilizer and potted up after they have been weaned.
Seed should be sown at a depth of 2-3 mm in late summer to autumn (February to March) in a well-drained sandy loam. Germination should occur in 1-3 weeks with percentage germination of ±75%. Remember that plants grown from seed will show some degree of variation and, if a particular form or variant is required, it must be propagated vegetatively.
- van der Walt, J.J.A., 1977, Pelargoniums of Southern Africa, Purnell, Cape Town, Johannesburg, London
- Kirstenbosch Horticultural Notes
- Smith, C.A., 1966, Common Names of South African Plants, Dept. of Agricultural Technical Services, Botanical Survey Memoir No 35, Government Printer.
- Leistner, O.A. (ed.), 2000, Seed plants of southern Africa: families and genera, Strelitzia 10., National Botanical Institute, Pretoria
- van Wyk, B.E., van Oudtshoorn, B., Gericke, N., 1997, Medicinal Plants of South Africa, Briza Publications, Pretoria, South Africa
Ebrahim Lawrence & Alice Notten
Kirstenbosch National Botanical Garden
Plant Type: Perennial, Shrub
SA Distribution: Western Cape
Soil type: Sandy
Flowering season: Spring, Early Summer
Flower colour: Purple, White, Pink
Aspect: Full Sun, Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Easy