Dymondia margaretae is a one-of-a-kind, hardy, carpet-forming groundcover with a compact, neat habit and stunning blue-grey foliage. It is perfect for those tight spots between stepping stones and sunny courtyards.
Dymondia margaretae is an e vergreen perennial, 50 mm high with a creeping, much-branched rhizome, at or just below the surface. It is fast-growing, forming a dense, spreading, flat mat of growth, which completely covers the surface. Blue-grey, basal leaf rosettes are borne on short erect shoots from the rhizome. The leaves are small, rigid and thick, linear-oblanceolate (narrowly lance-shaped with the broadest part above the middle), with 2–3 shallow, obtuse teeth on each side. Leaf margins are slightly incurved showing the pale, felt-like undersides. The upper leaf surface is dark green and glabrous (hairless). Small, solitary, stalkless, daisy-like yellow flowers, 25 mm in diameter, appear year-round, peaking in spring and early summer. The inflorescence is made up of female ray florets and bisexual disc florets. The fruit is a glabrous cypsela with a pappus of two rings of short hairs, which aid dispersal.
Dymondia margaretae is endangered (Raimondo et al. in prep.), it faces a very high risk of extinction in the wild. Its geographic range is estimated to be less than 5 000 km², severely fragmented or known to exist at no more than five locations, with projections of continuing decline due to its extent and/or quality of habitat. It is quite ironic that D. margaretae is endangered due to its reduced habitat, while its horticultural distribution expands worldwide!
Distribution and habitat
Dymondia margaretae is endemic to the Southern Overberg area ranging from Agulhas to Potberg, at altitudes of 160–200 m. It is found on well-drained, sandy, coastal flats and seasonally wet pans in slightly alkaline soils. It is tolerant of light frost and is drought resistant.
Derivation of name and historical aspects
Asteraceae is the most diverse family of flowering plants. The genera are well represented within the South African flora and particularly in the Cape Floristic region where 121 genera and 1 036 species occur, with 111 genera and 517 species in the southwestern Cape alone.
Dymondia margaretae, both genus and species, is named in memory of Miss Margaret E. Dryden-Dymond, the first collector who obtained plant material from the Bredasdorp District on a Kirstenbosch expedition in 1933. She was a member of the horticultural staff at Kirstenbosch National Botanical Garden. Only one patch of the plant was seen beside a road and although repeatedly searched for in later years, it was never again found. No further records were made until 1949 when Mr H. David brought in fragments from a collecting trip at the foot of the Potberg. Later in October 1950, the plant was found growing in the Bontebok National Park, covering a dry shallow pan. The most recent herbarium collection was in 2005 by N.A. Helme.
Dymondia margaretae stands alone in a genus of its own. Its closest resemblance is to Landtia and Arctotheca.
Dymondia is visited by many insects including bees, beetles and butterflies. It is not yet known which one, or if all of these, are pollinators. Seed is dispersed by wind, aided by the hairy rings of the pappus.
Uses and cultural aspects
Dymondia margaretae is widely used in horticulture as a hardy, stout groundcover and filler between stepping stones. It is a valuable landscape plant with its attractive appearance and hardiness and can be used in rockeries and coastal gardens. It is also well known as a lawn substitute. It handles light or limited pedestrian traffic and survives with lower water consumption than grass, making it an excellent water-wise alternative.
Growing Dymondia margaretae
Dymondia margaretae makes a wonderful groundcover and can be used to good effect under plants such as cycads (Encephalartos spp.) by highlighting their strong focal point. It is often used as a filler between pavers and railway sleepers, a border for pathways or a lawn substitute in sunny courtyards. It is a valuable plant in a coastal garden, helping to limit wind erosion in bare patches and retain soil on slopes. In areas of high rainfall it should be grown on a generous slope or raised rockery to improve drainage. It will tolerate being grown in light dry shade, but dies back in large unsightly patches if overwatered. It is tolerant of light frost.
This wonderful plant can be grown from seed, cuttings or division. The most usual and easiest method of propagation is division followed by tip cuttings. Vegetative propagation is best done in late winter or early spring as the plant prepares for its new growth season. Tip cuttings can be made from shoots off the rhizomes and, with the aid of a rooting hormone, should root within 3–4 weeks. Place tip cuttings into well-drained sandy soil and keep moist but not wet.
Runners from mature stands can be dug up and removed with roots to be replanted. Replanting is best done the same day, as the runners' chance of surviving is lessened the longer they are without soil. Plant into sandy, well-drained soil and add a generous amount of well-rotted compost. Plant approximately 200 mm apart for quick cover. Water new plants well until settled, and then water only as required.
A stressed Dymondia margaretae turns up its leaves, revealing more of the fuzzy whiter underside. Use an organic slow-release fertilizer to keep it growing vigorously and divide mature plantings every few years to retain vigour.
References and further reading
- Compton, R. H. 1953. Plantae novae africanae. Journal of South African Botany 19: 110.
- Goldblatt, P. & Manning, J.C. 2000. Cape plants. A conspectus of the Cape flora of South Africa. Strelitzia 9: 318. National Botanical Institute, Pretoria.
- Leistner, O.A. (ed.). 2000. Seeds plants of southern Africa : families and genera. Strelitzia 10. National Botanical Institute, Pretoria.
- Pienaar, K. 2001. What flower is that? Struik, Cape Town.
- Smith, C.A. 1966. Common names of South African plants. Memoirs of the Botanical Survey of South Africa No. 35.
- Trinder-Smith, T.H. 2003. The Levyns guide to the plant genera of southwestern Cape. Bolus Herbarium, University of Cape Town.
- Van der Spuy, U. 1975. Gardening with groundcovers. Protea Press, Stellenbosch.
Co-author Norma Lucas
Kirstenbosch National Botanical Garden