Drosanthemum floribundum (Haw.) Schwantes
Common names: purple carpet (Eng.); perstapeit (Afr.)
This hardy perennial produces dazzling metallic purple flowers in spring each year.
Drosanthemum floribundum is a low-growing, ground-hugging plant with small, stubby, light green, succulent leaves. It makes an ideal plant for waterwise gardeners, particularly those living in climates with hot dry summers. The typical mesemb flowers usually open about midday and close in the evenings. On dull, cool days they remain closed.
Distribution and habitat
The exact identification of this plant is somewhat unclear. Some authorities apply the name D. floribundum to a plant with a mainly coastal distribution around Cape Town, while others refer to a plant growing in the Little Karoo and in the vicinity of Worcester and Robertson. It is unlikely that these are both the same plant. Hopefully this matter will soon be clarified, but in this article we will be describing the plant as it grows in inland areas, although two of the photographs were taken of plants at Paardeneiland near Cape Town.
Derivation of name and historical aspects
The genus name Drosanthemum is derived from the Greek for dew, drosos, and flower, anthos, referring to the glittering appearance of many species.
The main pollinator of Drosanthemum floribundum is the Cape honey bee. Butterflies have been known to pollinate this species on the odd occasion.
These plants are water-misers, known to survive in very hot, dry climatic conditions. They grow flat (prostrate) on the ground and can easily colonize large flat open spaces in the Little Karoo; one plant can, in its lifetime, cover an area as large as 2m².
In the past these hardy survivors were planted in the gardens around Karoo homesteads and today one can still see surviving generations around deserted farmsteads.
In parts of the Little and Great Karoo Drosanthemum floribundum has proved to be an excellent feed for cattle, ewes and lambs. In times of drought famers in the Little Karoo fed these plants to their ostriches.
Growing Drosanthemum floribundum
These plants are very rewarding. They are hardy (drought- and frost-resistant). They can be planted in most garden situations, except for heavy pot clay. Individual plants live for 5-7 years, but if they are happy they may re-seed themselves. Remember succulents are water wise!
Collect ripe seed capsules in December, some 3 months after the plant has flowered. Lightly grind up the capsules to free the seed. Use a sieve to separate the fine, light brown seed. A conventional flour sieve will suffice for this sieving process.
Once the seeds have been separated from the ground-up capsules, they are ready for planting. Sow the seeds in amongst grit 2mm in diameter in a flat seed pan. Then cover the seeds with a fine layer (only 1mm thick) of loam soil using a flour sieve. Do not sow deeper than that, otherwise the seeds will not germinate easily. Keep the well-drained soil medium moist. Do not over-water at this stage. Use a fine spray for watering — water gently a otherwise the seeds will be washed out.
Under optimum conditions the seeds will germinate in 7 days. So, what are optimum conditions? The ideal time to sow these seeds is during the months of March, April and May, this being when the winter rains usually start in the Little Karoo.
The seeds will germinate rapidly. Once they have six leaves, prick them out and plant into a one pint plastic bag or a small 6 cm plastic pot.
If they have been cultivated under shade conditions, remember to harden them off by exposing gradually to bright sunlight before they are planted directly in full sun. From seed sown in March there is a possibility of flowering plants by September. Once they have germinated, growth is very rapid.
Karoo Desert National Botanical Garden
with additions by Yvonne Reynolds
Plant Type: Ground Cover, Succulent
SA Distribution: Western Cape
Soil type: Sandy, Loam
Flowering season: Spring
Flower colour: Purple, Mauve/Lilac
Aspect: Full Sun
Gardening skill: Easy