Erica glomiflora var. glomiflora is a variable and attractive species exhibiting a wide range of flower shapes and forms that brighten up the southern Cape Mountains with their profusion of attractive, lantern-shaped flowers. A very beautiful magenta form occurs on the Cloete’s Pass.
Erica glomiflora var. glomiflora forms an erect, well-branched, bushy shrublet, between 0.7 to 1.0 m tall. Most specimens grow into tight compact shrubs, but a few may grow into open branched, straggly specimens. The species is eye-catching because it displays hundreds of flowers covering most of the plant. It also produces a variety of flower sizes and shapes, ranging from small, medium to large, urn-shaped or conical flowers. The corolla form on the Langeberg and western Outeniqua Mountains, is typically urn or lantern shaped, whereas, flowers further east and on the Swartberg, are more round than long. The flower colour ranges from white to deep pink or even magenta red, and are slightly sticky. It has a long flowering season extending from autumn until mid-summer, from April to December or January.
This species was not selected by the SANBI Red List assessors in any one of four screening processes for highlighting potential taxa of conservation concern for detailed assessment and was hence given an automated status of Least Concern (LC). This is probably because it is well known and widespread and is not facing any threats.
Distribution and habitat
Erica glomiflora var. glomiflora occurs over a wide area along the southern Cape coastal flats and on the Langeberg and Outeniqua Mountains from Riversdale to Humansdorp. It also occurs on inland mountains from the Swartberg near Oudtshoorn and on the Kammanassie and Kouga.
Derivation of name and historical aspects
The name glomiflora describes the shape of the flowers, glomus, from the Latin meaning shaped like a skein or ball of yarn. The species was probably given its name after the form occurring in the Attakwaskloof west of the Robinson Pass.
Harry Bolus (1834-1911) described a variety, Erica glomiflora var. canthariformis, based on a single specimen collected by Scottish botanist and gardener, Francis Masson (1741 – 1805). Bolus said it had larger flowers, 8 mm long, with a longer neck, whereas the typical variety had flowers 5-6 mm long and egg to urn shaped. The large flowered variant in the Cloete’s Pass area is striking and could possibly be taken as var. canthariformis as Masson probably collected it there. There is much variation in Erica glomiflora and its very close relatives Erica tragulifera and Erica spectabilis, therefore separating the variant off just on the above characters is difficult. (Dr. E.G.H. Oliver, pers. comm.)
Erica glomiflora var. glomiflora grows in well-drained, sandy, acidic soils on mountain slopes and along the coastal plains of the southern Cape. The climate is basically Mediterranean, however, the southern Cape receives rain throughout the year. Therefore, the soils it grows in are often damp in summer. Populations are found concentrated in seepage areas on mountains or on the cooler, damper, southern slopes.
Sunbirds have been seen pollinating this species, although it is likely that it is also pollinated by insects. Plants are killed by fire and regenerate from seed.
Erica glomiflora var. glomiflora is suitable for gardens that are cooler and obtain extra water in summer. It is a very satisfactory plant flowering over many months, and is a good cut flower. It also makes a wonderful container plant.
Growing Erica glomiflora var. glomiflora
The lantern heath grows in deep, well-drained, moist, sandy soils. The ideal soil pH is between 5.5 and 6.7. It is easily grown from seed which should preferably be sown in autumn in the Western Cape. In other regions it should probably be germinated at the beginning of the growing season. Treatment with smoke or smoke extract greatly enhances germination. The seed takes about six to ten weeks to germinate and the seedlings are delicate in their early stages. It is important not to sow too thickly as seedlings growing too close together and overwatering may result in damping off. The young seedlings should be protected from heavy rainfall and direct sunlight, by placing the trays under cover while still providing good light and aeration. The seedlings should be watered gently to avoid washing them out of the tray or flattening their young delicate stems. Allow the young plants to grow to about 10 mm tall before planting them out into multi-trays or small pots or bags. Plants should be grown up to at least 100 mm before planting out in the garden.
Propagation from cuttings is more difficult and should be done with suitable facilities, such as mist propagation houses with heated benches and overhead misting. Cuttings are preferably taken in autumn in the winter rainfall Western Cape, but may be taken in spring or early summer as well. Use fresh, actively growing, thin side shoots taken as heel cuttings which yield the best results. A rooting hormone for semi-hardwood cuttings applied to the cut surface or heel, results in quicker and better rooting. Rooting may take from eight to sixteen weeks and sometimes longer. If the stem tip develops a callus, but does not root, score the callus and apply more hormone and place in fresh rooting medium. This often results in very good rooting.
Erica glomiflora var. glomiflora comes from the southern Cape where it receives rain throughout the year. It is generally found in dampish soils or seeps, so it is important to keep this plant moist during the summer. It should do well in most gardens in South Africa where the humidity is not too high and where there is no frost. They should do well in coastal gardens as long as the soils are acidic and they are not exposed to direct salt-laden wind. It grows well in various garden aspects, including open beds, rockeries and on slopes.
Feed before flowering with slow release 3:1:5 or monthly with a good organic seaweed-derived fertilizer. Be careful not to disturb the roots and water regularly as this is generally the cause of losses with ericas. Good results have also been achieved when applying controlled release fertilisers suitable for erica. Be careful not to exceed dosage.
Pruning will increase flower production, resulting in splendid displays, and increase the life expectancy of the plants. Ericas are relatively short-lived fynbos plants and survive on average up to between ten and fifteen years, after which they need to be replaced.
It is a prolific flowerer and is a wonderful addition to the garden.