This endangered member of the protea family makes an unusual addition
to sandy coastal gardens.
trilopha is a sprawling, multistemmed, resprouting shrub. It
grows to a height of 0.3-0.8 m and has a spread of up to 0.8 m.
The short, dissected leaves, which are characteristic of serrurias,
are hairless when mature. The plant produces a coconut-scented,
pink flowerhead during spring to early summer (from August to October).
The seeds are released within two months of flowering. The Red Data
List categorizes this species as Endangered.
Serruria trilopha grows in acid, sandy soils at low altitudes
between 50-310 m on the Cape Flats. The plant experiences typical
Western Cape weather which is cold and wet during winter and hot,
dry and windy during the summer months. The trident spiderhead is
naturally a lowland species and was once widespread over the Cape
Peninsula, Cape Flats and as far north as Malmesbury and Darling.
The species is endangered mainly because of rapid urbanization,
invasive aliens taking over its habitat and agriculture. According
to Tony Rebelo (1999) there are less than 500 plants that remain
in the wild, and most of them are along the road verges of the N7
freeway in the Cape Town area.
Derivation of name
The genus was named after J. Serrurier, a professor of botany at
the University of Utrecht in the early eighteenth century. The species
name trilopha refers to the short leaves that are dissected
into three segments. The common name snake-stem spiderhead refers
to the long and robust stems which 'snake' along the ground.
Serruria trilopha is adapted to surviving in the wild by
reproducing from seed. Once the seed ripens it is shed from the
flowers and falls to the ground. The seeds are tiny, hard-shelled,
oval nuts covered by a fleshy skin called the elaisome. The elaisome
secretes a chemical substance that attracts ants. The ants carry
the seeds to their underground nests where the fleshy skin is consumed.
The seeds remain underground until conditions are right for germination.
Serruria trilopha is adapted to surviving fires by resprouting.
Although the above-ground parts of the plant are burnt, the plant
bounces back and resprouts. The plants may flower profusely the
year following a fire, and will grow strongly and flower well in
the first two years after a fire, but will flower less and become
Growing Serruria trilopha
Serruria trilopha can be grown from cuttings or seed. Tip
or heel cuttings are taken during spring or autumn. A rooting hormone
is applied to the semi-hardwood cuttings. The rooting hormone will
help stimulate rooting. The cuttings are rooted in a soil mixture
of 50% milled pine bark and 50% polystyrene granules. Successful
rooting will happen if the propagation house has good misting and
underbench heating. Rooting of this species takes quite long, up
to 6-7 weeks. Once rooted the cuttings are removed from the mist
bench and hardened off for 4 weeks. The hardened-off cuttings are
then potted in a soil mixture made up especially for fynbos plants.
A suitable well-drained soil mixture consists of composted pine
bark, acidic river sand in equal parts loam/topsoil.
Seed is collected from the mature flowerhead. The seed should be
sown in late summer or early autumn (March-April). The higher day
temperatures and cooler night temperatures play a vital role in
initiating germination. The seeds can also be exposed to short periods
of high temperatures followed by cooling water, which, by copying
the autumn temperature, stimulates the seed to germinate. The seeds
should be treated with a fungicide that prevents pre- and post-emergence
damping off. The young seedling or cuttings should be grown in an
area that is well ventilated and covered with 50% green shade netting.
The plants should be watered in the mornings and you can feed with
an organic-based fertilizer to boost their growth. The young plants
can be planted out in autumn or in the cooler months before the
onset of summer. This will allow the root system to become established
and gives the young plant a good chance of surviving the hot summer
Serruria trilopha is best suited for a garden that has sandy
soil. It is a relatively small shrub so plant it in your garden
among slightly taller growing plants. The plant is a resprouter
so you could prune it occasionally to keep it neat and compact.
Plant in full sunlight and a layer of composted mulch or woodchips
will help keep the soil cool and provide the plant with nourishment.
- Rebelo, A. G. 1995. Sasol proteas. A field guide to the proteas
of southern Africa. Fernwood Press, Cape Town.
- Rebelo, A. G. 1999. West Coast proteas. A field guide to
the proteas of the West Coast. Protea Atlas Project, National
Botanical Institute, Cape Town.
- Vogts, M. 1982. South Africa's Proteaceae. Know them and
grow them. Struik, Cape Town.
Kirstenbosch National Botanical Garden