Admired for their graceful, wand-like stems, eye-catching pink flowers and erect, long, linear leaves, this easily cultivated plant is one of the most rewarding evergreen irids to grow.
Dierama pendulum is an evergreen geophyte (a plant that grows from subterranean buds attached to specialized storage organs) reaching up to 2 m high. The subterranean storage organ is a rounded, flattened corm that is annually renewed, and is surrounded by several fibrous outer layers. The old corms are persistent as they remain intact for many years, eventually forming long stacks, the corms placed one above the other.
The corms produce numerous tough, linear, erect, basal leaves up to 0.9 m long, and its striking pendulous, bell-shaped blooms are borne on a long arching, branched inflorescence. Flowers range in shades of pink, or rarely pure white, and measure up to 50 mm long, with a distinct perianth tube up to 13 mm long.
The fruit is a tough, rounded capsule bearing numerous brown, hard, angular seeds.
Dierama pendulum is a protected species and is currently not threatened.
Distribution and Habitat
The genus Dierama is endemic to Africa and contains some 45 species distributed from the southern Cape in South Africa to the highlands of Ethiopia. Its greatest diversity is found in KwaZulu-Natal, where about 26 species occur. Dierama pendulum is one of the most well-known and desirable members and has a somewhat limited distribution extending from Knysna in the southern Cape, to the Zuurberg and Grahamstown in the Eastern Cape. It frequents grassy slopes and flats in full sun in stony or marshy ground, and its flowering period extends from early spring to early summer.
Derivation of name and historical aspects
The genus name Dierama is derived from an ancient Greek word meaning a funnel, referring to the shape of the flower, while the specific epithet pendulum is derived from Latin and refers to the pendulous branches of the inflorescence. Dierama pendulum was the first member of the genus to be discovered in the wild, and was gathered for the first time near the Kromme River in the Eastern Cape in the early 1770s by the great Swedish botanist, Thunberg.
The flowers of Dierama pendulum are pollinated by honey bees.
Uses and cultural aspects
Dierama pendulum is not known to be used culturally or medicinally by the indigenous peoples of southern Africa.
Growing Dierama pendulum
The cultivation of Dierama pendulum presents no great difficulty provided that a few simple points are borne in mind. The plants are evergreen, but nevertheless undergo a rest period from autumn to the end of winter, during which they are able to survive relatively dry conditions, whereas from early spring until late summer they require regular heavy watering. The corms do however, easily withstand moisture during their winter rest period. As the corms are never completely dormant, they should not be lifted and stored dry as this will soon lead to desiccation and death within a few weeks.
The plants require as sunny a position as possible and it is important to note that even during their winter rest phase, they must receive adequate sun or very bright light for them to produce flowers from early spring to early summer. They prefer a slightly acid, well-composted loam and perform equally successfully in both well-drained and boggy conditions. They form dense clumps with age and these should be left undisturbed for up to five years or more, until flowering frequency diminishes, or propagative material is required. The green leaves of all dieramas should never be cut back as this severely retards growth and flowering; only the outer, brown, old leaves should be removed by gentle tugging. D. pendulum is most effectively displayed on raised banks overhanging garden ponds, but can also be used in many other parts of the garden such as in rockeries or borders, provided it received sufficient sunlight. Most of the species including D. pendulum are at least able to withstand light frost, and all the species are perfectly hardy in mild parts of the northern hemisphere. Propagation is easily achieved by means of fresh seeds sown in spring, or by division of thick clumps in spring, ensuring that divisions are replanted immediately, and kept well watered.
The leaves of Dierama pendulum and many other members of this genus are highly suscpetible to red spider mites and the rust fungus Uromyces transversalis. Red spider mites are problematic during the hot summer months and attack both surfaces of the leaves, resulting in a silvery-bronze sheen, for which spraying with mineral oil can be used as a measure of control. Ensuring that plants receive adequate sunlight throughout the year, assists in reducing the incidence of rust fungi. The corms of all dieramas are relished by mound-forming mole rats and in susceptible areas they should be planted into sunken, sturdy wire baskets.
References and further reading
- Duncan, G.D. 1996. Growing South African bulbous plants. National Botanical Institute, Cape Town.
- Duncan, G.D. 2000. Grow bulbs . Kirstenbosch Gardening Series. National Botanical Institute, Cape Town.
- Du Plessis, N.M. & Duncan, G.D.1989. Bulbous plants of southern Africa, a guide to their cultivation and propagation. Tafelberg Publishers, Cape Town.
- Hilliard, O.M. & Burtt, B.L. 1991. Dierama, the hairbells of Africa. Acorn Books, Johannesburg & London.
Kirstenbosch National Botanical Garden