Plectranthus hadiensis var. hadiensis is an attractive perennial shrub with decorative foliage, suitable for planting in humid, moist and lightly shaded areas in small gardens.
Plectranthus hadiensis var. hadiensis is a herbaceous perennial, 1.5 m high and 1 m wide. The semi-succulent stems are red at the base and leaves are arranged alternately with axillary buds at the base of leaf petioles. Leaves are ovate to round, 35–100 mm wide, delicate, soft and hairy, sometimes variegated. Margins are toothed with 4–14 pairs of teeth.
The terminal inflorescence is 500 mm long with pairs of side branches and mauve to white flowers arranged in a whorl, 10–30 mm apart. Flowering time is from autumn to winter with a peak in autumn (April to June). The corolla is 8–15 mm with a down-turned tube that widens towards the throat. Calyx is 2–3 mm and enlarges to 5–6 mm after flowering.
Dark brown nutlets, 8 mm in size, are formed and released when ripe.
Plectranthus hadiensis var. hadiensis is not threatened and Red-Listed as Least Concern.
Distribution and habitat
Plectranthus hadiensis var. hadiensis has a widespread distribution from the Eastern Cape and KwaZulu-Natal provinces in South Africa to the Arabian Peninsula. It o ccurs in forests and open grassland in well-drained, rich soil, usually amongst rocks where annual rainfall is between 700 and 1 000 mm.
Derivation of name and historical aspects
Plectranthus is derived from the Greek words plectron, meaning spur, and anthus, meaning flowers, which refers to the characteristic spur on the base of the corolla tube – hence the common name, spurflower. The species name hadiensis is derived from the Arab name from where it was first collected, the Hadiyah Mountains in Yemen. Plectranthus is a genus in the family Lamiaceae. Members of the Lamiaceae typically have square stems, whorled flower arrangements, aromatic oils and two-lipped flowers.
There are 350 Plectranthus species, which are widely distributed in Africa, India and Australia, with 53 species found in South Africa and Namibia. The South African species with the greatest horticultural potential are found from the Eastern Cape to KwaZulu-Natal.
Plectranthus hadiensis var. hadiensis was first discovered by Pehr Forsskål in Hadiyah, Yemen and it was named Ocimum hadiensis in 1775 in the Flora of Egypt and Arabia (Van Jaarsveld 2006). The genus Plectranthus was not yet established, but it was the first Plectranthus to be described and was only transferred to Plectranthus in 1894 by the botanists Schweinfurth and Sprenger. Plectranthus hadiensis var. hadiensis is closely related to P. grandidentatus which has light green leaves with large-toothed margins, and P. madagascariensis which has smaller leaves, a cascading growth habit and white flowers.
There are three varieties of Plectranthus hadiensis:
- var. hadiensis which occurs in the middle and coastal areas of KwaZulu-Natal forests and eastern parts of South Africa;
- var. tomentosus which is found in semi-coastal areas from the Kei River towards the coast of KwaZulu-Natal and extending inland; and
- var. woodii which has tuberous roots that help it to survive fire in the dry woodlands of the Eastern Cape and KwaZulu-Natal.
Plectranthus hadiensis var. hadiensis looks like a soft perennial yet it is surprisingly drought-tolerant. It adapts easily in dry areas, as it has semi-succulent stems. During periods of drought it will wilt, but will recover soon after it receives water. They root at the nodes of broken branches, usually in summer-rainfall forests rather than in dry grasslands, and thus have a way of spreading vegetatively.
Uses and cultural aspects
In the past Plectranthus hadiensis var. hadiensis was used to poison fish and traditionally used as a medical enema. It is also used as a charm against evil spirits.
Plectranthus hadiensis var. hadiensis is a decorative perennial with horticultural potential. Kirstenbosch has a number of cultivars that have been released to the plant trade.
Growing Plectranthus hadiensis
This Plectranthus has become a good garden plant. It is fast-growing, easy to propagate, requires little maintenance, is a good pot plant, and also gives gardeners that think they don't have green fingers a burst confidence.
Plectranthus hadiensis var. hadiensis is best propagated vegetatively by means of tip and stem cuttings in summer. Take cuttings from a healthy and disease-free mother stock at the coolest time of the day, preferably morning when the plant is vigorous. Use well-drained soil, such as river sand mixed with perlite, vermiculite or pebbles. Cut the stem at 150 mm below the node, remove a third of the leaves from the bottom. Rooting hormone is not necessary. Keep the cuttings in a warm, humid area with good air movement and keep the soil moist but not wet. Rooting takes place after 2–3 weeks and once well-established, transplant cuttings into containers and water regularly until they are fully grown. Established plants can be transplanted into bigger containers or into the garden.
Plectranthus hadiensis var. hadiensis is a decorative plant that is easy to grow, and ideal for either planting in the garden or for potted specimens. Plant them densely together for a thick and compact foliage in garden beds. This species performs very well in well-drained, composted soil and requires occasional water in summer. Feed with an organic fertilizer to improve the plant quality. Pinch out spent inflorescence to encourage new growth and buds. Prune the tips of the braches to control and encourage growth. Few pests attack these plants.
References and further reading
- Codd, L.E., De Winter, B., Killick, D.J.B. & Leistner, O.A. 1985. Flora of Southern Africa 28(4): page numbers.
- Pooley, E. 1998. A Field Guide to Wild Flowers KwaZulu-Natal and the Eastern Regions . Natal Flora Publications Trust, Durban.
- Van Jaarsveld, E. 1987. The Plectranthus Handbook . Kirstenbosch National Botanical Garden, Cape Town.
- Van Jaarsveld, E. 1994. The genus Plectranthus and the introduction of recent new cultivars. Hortagro 1: 16–18.
- Van Jaarsveld, E. 2006. Southern African Plectranthus , the art of turning shade into glade . Fernwood Press, Simon's Town.
Kirstenbosch National Botanical Garden