A beautiful, colourful mass display of Drosanthemum bicolor flowers awaits you on your visit to the Karoo Desert National Botanical Garden in spring.
Drosanthemum bicolor is an erect small shrub, 1 m high, with a shallow root system. The short-lived, easily dropping leaves have prominent water cells which glisten in the sunlight. The daisy-like flowers are yellow with red tips borne in spring (September-November). The fruit is a capsule and the seeds are brown and round.
Drosanthemum bicolor is not a threatened plant.
Distribution and habitat
Drosanthemum bicolor grows in decomposed Malmesbury shale on hillsides in the western Little Karoo. This plant comes from the winter rainfall area and is suitable for to cultivation in most Western Cape gardens.
Derivation of name and historical aspects
The name Drosanthemum is derived from the Greek words for dew, drosos, and flower, anthos, referring to the glittering appearance of the many species. The word bicolor is Latin for two-coloured, referring to the colour of the flowers. There are 120 Drosanthemum species listed in Smith et al. (1998). A noteworthy member of the genus is D. speciosum with scarlet red flowers.
Bees possibly pollinate the brightly coloured flowers. The flowers open only on warm, sunny days and close in the evening. Seed dispersal is triggered by rain (moisture) opening the seed capsules. The raindrops wash the seeds out of the seed capsule. This mechanism ensures survival of seed germination. The seed is washed away from the parent plant and grows under the protection of a nurse plant. A nurse plant is a shrub that shelters the seedlings from the sun's damaging rays.
Once the seed capsule loses moisture and dries, it closes again.
Uses and cultural aspects
There are no medicinal or traditional uses associated with these plants. Drosanthemum bicolor is horticulturally popular in most gardens. Use in a rockery, with other low-growing succulent plants. It ensures a colourful garden in spring. Alternatively, plant masses of this plant in the garden to create a more spectacular picture than only a single specimen. These plants are hardy, water-wise and require low maintenance-a gardener's dream come true.
Growing Drosanthemum bicolor
Use Drosanthemum bicolor in the garden with other colourful mesembs (vygies). Plants die after some years and care should be taken to keep seedlings for replacement.
They grow easily from seed and cuttings. To speed up germination, allow the seeds to soak in hot water for a day before sowing. Do not boil the seeds in the water. Sow seeds in autumn or summer in a seed tray of river sand, scatter over a large area, as overcrowding of seeds will cause damping off. Care should be taken to sprinkle the sown area lightly with river sand. Place seed tray in a sunny position, keep the soil medium moist (use a mist sprayer) and after two weeks the seeds will germinate. Cuttings should be taken after fruiting, from midsummer to autumn (December to April in South Africa).
White scale is a pest on the plants. To control this use a horticultural oil-based product to smother these insects.
References and further reading
- Manning, J. 2001. First field guide to succulents of southern Africa. Struik, Cape Town.
- Smith, G.F, Chesselte, P, Van Jaarsveld & E.J., Hartmann, H. 1998. Mesembs of the world. Briza Publications, Pretoria.
Karoo Desert National Botanical Garden