This dainty member of the protea family is threatened with extinction
as its habitat disappears.
Mention of the name protea, conjures images of sturdy bushes with
large, spectacular flower heads. Plants making up the genus Diastella
are of the protea family, but far from being robust they form delicate
shrublets and groundcovers with the most charming clusters of flowers.
The name 'Diastella' is derived from the Greek word diastellein,
which means 'to separate'. This refers to the soft, silky flower
segments that are joined at the base, but are otherwise free. The
flowers are crowded into small 10-12mm diameter heads that resemble
little silky-puffs. The effect is that of a single flower, but they
are in fact aggregates of many flowers.
Diastella proteoides occurs on the Cape Flats from Tokai
near Constantia eastwards to Eerste River and Paarl and northwards
to Mamre just beyond the town of Atlantis. A quick glance at the
map will reveal that most of this land has been developed for housing
and farming. This plant was once abundant on the Cape Flats, but
most of its southern populations have been destroyed. Small remnant
populations remain near Tokai. The plant carries a status of 'vulnerable'
in the Red data book and is likely to be upgraded to endangered
status as land is developed north of Cape Town.
proteoides is a low growing, sprawling shrublet with long lax
branches forming mats up to 3m in diameter. It has the tendency
to grow up through the branches of other shrubs to a height of 0.5m,
whereas normally it is lower growing. Fine linear leaves radiate
from thin hairy stems that are characteristically red in colour.
The small flower heads, 10mm in diameter, form at the ends of the
branches. Each flower head has an attractive rosette of pointed
pink star-like, hairy bracts. The little flowers aggregate in puff-like
clusters from the bracts. Flowers are produced erratically throughout
the year, but mainly from July to February.
This plant grows in deep, well-drained, sandy, acid soils that
are poor in nutrients. It grows in full sunlight, but can be closely
accompanied and partially shaded by other shrubs. The Mediterranean
climate normally provides plenty of winter rain and dry summers.
The habitat is also characterised by fresh to strong winds, which
help to keep the foliage dry and the humidity down. This is important
to know, as this plant is susceptible to the normal range of protea
fungal infections that are encouraged by wet and warm conditions.
It usually produces a single small seed in each flower head, which
drops to the ground when mature. These are either taken underground
by ants or eaten by rodents. Seeds normally germinate in autumn
after fire. Germination is much encouraged after the mature vegetation
is burnt away. A burning cycle with long enough gaps to allow re-growth
and adequate seed production is a necessary part of the growth cycle.
Growing Diastella proteoides
Diastella proteoides is mostly propagated from heel or tip
cuttings taken in spring or autumn. The cuttings are treated with
a rooting hormone used for encouraging root development of semi-hardwood
cuttings. Cuttings are placed in shallow trays or preferably compartmentalised
propagation trays and placed on heated benches and under mist or
fog. A typical rooting medium would include equal parts milled pine
bark and polystyrene pellets. Rooting is not as easy as with pincushions,
but between 30 - 50% success has been achieved. Rooted cuttings
are planted and grown in a sandy well-drained acid, potting medium.
Regular feeding with an organic seaweed based fertiliser is recommended.
This plant has seldom been grown from seed, as it is very time
consuming to collect the seed. If seed were sown it should be dusted
with a fungicide to counter pre-emergence damping off and sown in
late summer or autumn.
Diastella proteiodes has proved difficult to grow and sustain
in a healthy condition at Kirstenbosch. This is probably because
it prefers drier conditions than are the norm in the nursery or
the gardens. The plant suffers from a wide range of fungal infections
and therefore the cost of keeping it healthy through intervention
with fungicides is prohibitive. Ex situ conservation in nurseries
is therefore not a viable and sustainable option.
In situ conservation, which is in its natural habitat, is
the best option for this species. Near Cape Town, the population
in the Tokai forest is very important, as it is the last viable
population in the southern distribution. The heritage area at Plattekloof
near Monte Vista is also important as it forms corridors of natural
flora that can be preserved providing that the land is properly
managed. Preservation of populations north of Cape Town has become
more important with the ever-increasing pressure for land.
Ex-situ conservation in nurseries and Botanic Gardens has
been mentioned as not sustainable. The only alternative is to gather
a percentage of seed and put it into long storage in the Millenium
Seed Bank at Wisley, which is under the jurisdiction of the Kew
Botanic Garden. This will serve as an insurance against possible
- Adamson, R.S. & Salter, T.M. 1950. Flora of the Cape Peninsula.
Juta&Co: Cape Town and Johannesburg.
- Goldblatt, P. & Manning, J. 2000. Cape Plants, A Conspectus
of the Cape Flora of South Africa. Strelitzia 9. Publ. Jointly
by NBI & Missouri Botanic Garden.
- Rebelo, T. 1995. SASOL Proteas, a field guide to the Proteas
of Southern Africa. Fernwood Press: Cape Town.
- Vogts, M. 1982. South Africa's Proteaceae. Know them and grow
them. Struik: Cape Town.
Kirstenbosch National Botanical Garden