Streptocarpus baudertii L.L.Britten
Common names: Cape primrose, wild gloxinia
Streptocarpus baudertii is a small herbaceous delight, with pretty mauve flowers and hairy leaves. It is special because it is not usually found in the home garden.
Streptocarpus baudertii is a small herbaceous perennial lithophyte (grows on rocky or stony ground). An unusual feature of this plant is that no stems are present — each leaf is actually an individual plant with its own roots and flowering stems. Leaves are dark green, roughly velvety and hairy, arranged in a rosette formation flat against the ground.
Flowers of all Streptocarpus have a tiny five-lobed calyx backing a tubular corolla that flares out into a five-lobed mouth. These pretty flowers are narrowly funnel-shaped with a curved tube that is strongly flattened at the mouth, thus keyhole-shaped, violet with a white patch on the lower lip which is patterned attractively with deep purple lines. The slender inflorescence stalks arise from near the bottom of the midrib of each leaf and carry small clusters of one to three flowers in summer from December to February.
Flowers are followed by velvety fruit capsules that twist open in a spiral when dry, releasing a large amount of very small, light seeds.
Many of the Streptocarpus species are very specific in their distribution and occur in very small populations, making them vulnerable to any disturbance. According to IUCN the threat status of Streptocarpus baudertii is Least Concern.
Distribution and habitat
This species is found in Kwazulu-Natal and in the Eastern Cape on sandstone cliffs among scrub, usually in seams of turf and under rocky outcrops at an altitude of between 60 to 1 750 m.
Derivation of name and historical aspects
The name Streptocarpus is derived from the Greek words streptos meaning twisted and carpus meaning fruit, which is a perfect description of the plant's spirally twisted seed pods.
Streptocarpus belongs to the same family, Gesneriaceae, as the well-known African violets (Saintpaulia) and gloxinias (Sinningia) that are grown as pot plants all over the world. Gesneriaceae — named in 1963 after the Swiss scholar Konrad Gesner 30 years after his death — is a large family of mostly tropical and subtropical herbs, with ± 139 genera, and ± 2900 species worldwide. There are eight genera in Africa, with one genus, Streptocarpus in South Africa; it has ± 45 species mainly in the eastern half of the country; usually in cool, moist habitats, sometimes epiphytic or lithophytic.
In 1826 the collector James Bowie took the first plants of Streptocarpus rexii to Kew Botanical Gardens in England. As more species were introduced into cultivation different hybrid Streptocarpus were produced. Today new hybrids are still being introduced to the huge and growing pot-plant market.
Gesneriaceae are often epiphytic (growing on trees) or lithophytic (growing on rocks). The plants can cross-pollinate easily with other species but in many instances are self-pollinated. The very small seed is wind distributed.
Some species of Streptocarpus are used in Zulu medicine where leaf infusions are drunk to ease labour pains.
Growing Streptocarpus baudertii
Streptocarpus baudertii is a plant that is seldom seen in gardens due to its unavailability in the trade and because it can be difficult to grow under home garden conditions.It does best as a pot plant rather than planted out in the garden. Ensure a warm spot with good light but no direct sunlight. The plant in general is very sensitive to light, is burned easily by the sun, and flowers poorly in deep shade. Light shade with good ventilation is best for growing healthy plants with plenty of flowers.
Watering Streptocarpus should be done with care. It is very important that the plants should not be over-watered, to prevent rotting and fungal problems. Allow them to get quite dry between watering; they can be allowed to wilt slightly as they have the ability to recover very well from this. Be aware though that severe wilting can also be a sign of root rot caused by over-watering, so check the medium to see that this is not the case. During the warm summers when they are actively growing, they need plenty of water. Most Streptocarpus species have a 'rest period' during winter, so they will need very little water during this slight dormancy period.
To keep the plants looking attractive and to discourange fungal growth, regularly remove all dead, unhealthy, dying leaves and flowers. Also, removing spent flower heads will encourage a longer flowering period as it encourages new flower development.
The tips of the leaves often die off as they get older and when stressed by drought or low temperature or when overwintering. This survival tactic does not harm the plants, as although the dead ends may look unattractive, each leaf simply forms an abscission layer and continues with new growth from the base. Regular feeding during the growing season with liquid foliar feed is recommended.
All propagation is best done in spring which is the start of the growing season. Streptocarpus baudertii can easily be grown from seed. When sowing the seeds, mix a pinch of the dust-like seeds with a small amount of sand to assist with spreading the seeds evenly. Use a well-drained medium that is not too coarse. Cover with a very thin layer of sand, keep out of direct sun but in warmth. Water regularly with a fine spray. Germination usually takes 3-4 weeks. Do not allow the seedlings to dry out. Better germination results are often obtained if the seed tray is covered with a glass sheet or enclosed in a clear plastic packet. Plant the seedlings into small pots only once they are quite big and strong. Transplant again into bigger pots when the roots have filled the small pots.
Repotting of plants should commence once the roots appear at the bottom of the pot. Remember that with Streptocarpus it is better to under-pot than to over-pot as most of them have shallow root systems and in their natural habitats most often grow in very little soil, if any at all.
To get new plants identical to the parents, it is best to propagate from cuttings. Streptocarpus can be propagated from a single leaf and the best results are from leaf cuttings taken in spring and early summer. A variety of mediums can be used as long as they are well drained. Sand, bark, palm fibre and polystyrene or vermiculite in different ratios are all suitable. At Kirstenbosch we use 40% bark, 40% polystyrene and 20% riversand. Water the medium well and treat with a suitable fungicide before using. Select healthy youngish leaves from the centre of the plant and cut off using a sharp knife or blade. Remember that the most active region of the leaf is near the base where the growing region (meristem) is present and so this area will yield the best rooting results. If it is a small leaf, then insert the cut end of the leaf as is into a rooting hormone and then into the medium, larger leaves can be cut into 3 cm strips with each bottom cut end being dipped into rooting hormone.
Always take note of which way the leaf cutting should be orientated before dipping into a rooting hormone and place firmly into the medium but not too deep as this will encourage rot. Alternatively, cut along either side of the midrib and treat in the same manner. Plantlets will form along the base of the cut end, in one to three months depending on the species.
When the plantlets are well established, the 'old' leaf can be teased out from the medium and the little plantlets gently separated off and then potted up, usually between 6-12 months.
Plants that have grown quite large can also just be divided as a method of increasing them; do this in early spring and repot to grow on. Mature plants can lose their vigour after 3 to 5 years and propagation as described above can be used to replace them with younger plants.
Mealy bug, aphids and caterpillars are the most troublesome pests of Streptocarpus, but seldom cause severe problems. Caterpillars can either be hand collected or sprayed with a suitable poison, aphids can be sprayed, or removed carefully by running a thumb and forefinger along the flower stems- where they usually occur, if mealy bug is found on any part of the plant, quickly remove the affected parts and treat with a suitable pesticide. Kirstenbosch has had great success in managing infestations by using biological control with the natural predators of mealy bug.
Fungal infections are also a cause for concern; if fungus is found on any part of the plant, remove the affected parts and treat with a suitable fungicide.
Streptocarpus are usually prone to pests and diseases only when they not being treated or grown correctly — any plant that is stressed is more likely to come under attack. So, to reduce problems occurring, avoid overwatering, underfeeding, root bound plants, lack of good air movement/circulation.
- Burtt, B.L. & Hilliard, O.M. 1971. Streptocarpus, an African plant study. University of Natal Press, Pietermaritzburg
- Davidson, W. 1982. The houseplant survival manual. Hamlyn Publishing Group Ltd, London.
- Goldblatt, P. and Manning, J. 2000. Cape Plants. A conspectus of the Cape flora of South Africa. Strelitzia 9.
- Leistner, O.A. (ed.). 2000. Seeds plants of southern Africa: families and genera. Strelitzia 10. National Botanical Institute, Pretoria.
- Manning, J. 2001. Eastern Cape South African Wild Flower Guide 11. Botanical Society of South Africa, Cape Town.
- Phillips, R. and Rix, M.1997. Conservatory and Indoor Plants. Plants for Warm Gardens, Vol. 2. Pan Books, London.
- Smith, C.A. 1966. Common names of South African plants. Memoirs of the Botanical Survey of South Africa No. 35.
Kirstenbosch National Botanical Garden
Plant Type: Perennial
SA Distribution: Eastern Cape, KwaZulu-Natal
Soil type: Loam
Flowering season: Spring, Early Summer, Late Summer
Flower colour: Mauve/Lilac
Gardening skill: Average