The beautiful, but often overlooked, Colpias mollis (klipblom),
is a chasmophyte (a plant that grows in rock crevices). It thrives
on the granite hills so characteristic of the Namaqualand landscape,
in the Northern Cape.
is a low, much-branched shrublet, up to 200 mm high, with brittle
branches. The leaves and branches are covered with soft hairs and
during spring the small plants produce showy clusters of white or
yellow flowers with a sweet or clove-like scent.
The leaves are alternate, hairy, egg-shaped or triangular, with
toothed or incised margins. The perianth is divided into a five-partite
calyx covered with soft hairs and a tubular corolla, hairless and
somewhat curved at the base with two short pouches, lined with oil-secreting
The capsules are hairless, dehiscent along the partition and contain
many oblong, black seeds covered with small grains and wrinkles.
Distribution and Habitat
Colpias is confined to crevices in granite boulders throughout
Namaqualand. These plants are not restricted to a certain aspect
or slope type, but literature suggests that plants generally occupy
east- or south-facing rock faces. Plants have to withstand not only
a shortage of water and nutrients, but also wide temperature fluctuations
without the shading benefits provided by neighbouring plants.
Derivation of name and historical aspects
The genus Colpias consists of a single species which is endemic
to the dry northwestern parts of South Africa and possibly Namibia.
The species name mollis means softly hairy and refers to
the leaves and branches that are covered with soft hairs. The name
Colpias is derived from the Greek Kolpos meaning a
breast or womb and probably refers to the two pouches in the corolla
tube which resemble breasts.
flowers of Colpias last four to five days and are pollinated
by a specific Rediviva bee (Hymenoptera, Melittidae).
The female bees collect oil and pollen from the flowers, while the
males patrol the plants, presumably in search of receptive females.
Pollen grains of Colpias are small (± 23 µm),
have a semi-reticulate surface pattern (net-like, with holes and
walls) and show a tendency to stick together-an adaptation ensuring
easy attachment and transfer.
Appendages, called elaiosomes, containing lipid reserves are found
on the seeds, and ants are therefore suspected to be responsible
for dispersal of seeds to favourable microsites where germination
occurs. However, after fertilization, the flower stalks turn away
from the sunlight in the direction of the rock. This phenomenon
is described as a type of autochory (the plant itself acting as
dispersal agent) as the plant seeks a crack where the capsule deposits
its seeds. Seeds thus germinate under the same conditions as the
mother plant and survival of the species is ensured.
and cultural aspects
No information is available.
Growing Colpias mollis
No information on the cultivation of this plant is available. Personal
observations, however, showed that seeds germinate readily within
a few days but after a week or two the seedlings start to wither
and die, possibly as a result of a fungal infection.
This species has horticultural potential as the plants would make
beautiful, unusual rockery subjects and would also look most decorative
if grown between the rocks of a garden wall in the winter rainfall
- Cowling, R.M. & Pierce, S.M. 1999. Namaqualand. A succulent
desert. Fernwood Press, Vlaeberg, Cape Town.
- Eliovson, S. 1972. Namaqualand in flower. Macmillan,
- Jackson, W.P.U. 1990. Origins and meanings of the names of
South African plant genera. UCT Ecolab, Rondebosch.
- Le Roux, A. & Schelpe, E.A.C.L.E. 1988. Namaqualand.
South African Wild Flower Guide 1. Revised edition. Botanical
Society of South Africa, Cape Town.
- Patterson-Jones, C. 1997. The Cape Floral Kingdom. New
- Steiner, K.E. & Whitehead, V.B. 2002. Oil secretion and
the pollination of Colpias mollis (Scrophulaceae). Plant Systematics
and Evolution 235: 53.
National Herbarium, Pretoria