Erica brachialis Salisb.
Common names: hairy-tube heath
Erica brachialis is not the showiest of ericas; it is a long-lived, easy-to-grow and discreetly decorative shrub that is well suited to coastal gardens as it is unaffected by salty sea winds.
Erica brachialis is a sturdy, erect, woody shrub up to 2 m high. Old plants can develop a trunk up to 30 mm in diameter. Branches are numerous, rigid and densely leafy.
The flowers are large, tubular (14-16 mm long), starting out a bright green and turning pale yellow as they mature. They are firm and slightly sticky. They are carried mostly in umbels of 3 or 4, sometimes 1-6 flowers. The corolla tube is finely hairy on the outside and inside. The anthers are inside the tube - visible as a shadowy dark band roughly halfway up the tube. If you dissect a flower you will see that the filaments have a kink in them. The style is slender and protrudes slightly from the tip of the tube.
Old flowers shrivel, turn brown and the ovary at the base swells so that the old flowers develop an urn shape. They remain on the plant for many months, and are often seen alongside the fresh flowers. Flowering time is mid to late summer (January-February-March).
Endangered. Erica brachialis occurs in only six small, fragmented subpopulations and numbers fewer than 500 wild individuals, and the wild population is decreasing. It was known to occur at some locations on the northern Cape Peninsula where it is now locally extinct, because urban development has destroyed its habitat. The remaining populations are threatened by the spread of invasive alien plants, too frequent fires and housing developments, all of which are damaging and destroying what remains of its habitat.
Distribution and habitat
Erica brachialis occurs on rocky slopes, low coastal mountains, on granitic and sandstone soils, with some populations at or near sea level. It is seen from Gordon's Bay to Cape Hangklip, and on the Cape Peninsula from Camps Bay to Cape Point, although the populations at Camps Bay and Llandudno have been wiped out. It never grows very far from the sea and in some places is found amongst rocks very close to the sea, yet the plants are unaffected by salty spray or wind.
Derivation of name and historical aspects
The genus Erica gets its name from ereiko, to break, either because of the ability of the plant to break up bladder stones or more probably because the stems are brittle and break easily. This species name is from the Latin brachiale meaning of or relating to the arms or resembling an arm, or a bracelet or armlet.
Erica brachialis is a long-lived plant. The oldest known wild plant, with a trunk diameter of 40 cm, is estimated to be at least 200–300 years old. This species also has the ability to resprout, not from an underground rootstock, but from the trunk or a stem. This is known as natural coppicing. It enables a plant to survive damage such as being broken or knocked over. One would expect that it would also give the plant an advantage when it comes to surviving fires, but in fynbos that is burned frequently field observations by Ross Turner show many adult and juvenile Erica brachialis plants are killed by fire, with most of the population growing in rocky areas that are less affected by fire.
Unlike many other ericas, Erica brachialis does not flower prolifically and thus does not produce large quantities of seed, which would allow it to recolonise the area after a fire more readily. All this shows that Erica brachialis does not cope very well with frequent fires. It also indicates that in the absence of frequent fires E. brachialis would colonise a wider area, i.e. not just favour the rocky areas but also move onto the open slopes.
E. brachialis flowers are pollinated by the Orangebreasted Sunbird (Anthobaphes violacea), which visits to feed on the nectar, and while feeding, pollinates the flowers.
E. brachialis is unusual among ericas in that it keeps its ovaries, and seeds, on the plant for a season, sometimes longer, before shedding its seeds. It does not develop a thick protective covering for the fruits, like serotinous species do. (Serotinous species retain their seeds on the plant, usually in woody fruits or cones, for more than a year after they are ripe. Some species retain them for up to ten years.) The ecological or evolutionary advantage of Erica brachialis retaining it seeds for a year or so has not been explored.
Erica brachialis is not used in traditional medicine, nor is it a candidate for the cutflower trade, but it could be a useful and interesting horticulture subject, particularly in coastal areas.
Growing Erica brachialis
Erica brachialis is slow-growing, long-lived and easy to grow. It needs a sunny position, in well-drained, preferably acidic (pH 5–6.5) soil and is also suitable for containers. Mulch with well-rotted compost and keep root disturbance to a minimum. Grow it in the fynbos garden, coastal garden, Mediterranean garden, and in rockeries, shrubberies and similar situations. Try it as a bonsai.
Propagate by seeds or cuttings. Seeds are relatively easy to harvest as the old flowers are kept on the bush for months after flowering. Sow in late summer to autumn (March–April–May). Use a well-drained, acidic soil medium. Treat with Instant Smoke Plus Seed Primer to improve germination. The seeds are fine and need only a light covering. Water with a fine rose to avoid displacing the seeds. Germination takes 1–2 months. Transplant the seedlings when they are about 10 mm high and grow on in light shade until they are established.
Take semi-hardwood heel cuttings in late summer to autumn or spring. Treat with rooting hormone and place in a well-drained, well-aerated rooting medium in a mist unit with bottom heat of ±24 °C. Pot the rooted cuttings in a well-drained, acidic soil medium and harden off in light shade for a month or two.
- Bolus, H., Guthrie, F. & Brown, N.E. 1909. Flora Capensis vol. 4, page 2.
- Goldblatt, P. & Manning, J.C. 2000. Cape plants. A conspectus of the Cape Flora of South Africa. Strelitzia 9. National Botanical Institute, Pretoria & Missouri Botanical Garden Press, Missouri.
- Raimondo, D., Von Staden, L., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. & Manyama, P.A. (eds) 2009. Red List of South African plants 2009. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
- Schumann, D., Kirsten, G. & Oliver, E.G.H. 1992. Ericas of South Africa. Fernwood Press, Cape Town.
- Turner, R. 2009. A year of erica atlassing. Part 1: Erica patens and Erica brachialis. Veld & Flora 95(2): 86-89.
- Turner, R. 2010. Sunbird Surprise! Surprises in the world of plant pollination. Full Circle Magazine 17(3): 34.
Kirstenbosch National Botanical Garden
Plant Type: Shrub
SA Distribution: Western Cape
Soil type: Sandy
Flowering season: Late Summer, Autumn, Winter
Flower colour: Green, Yellow
Aspect: Full Sun
Gardening skill: Average