The spiny Barleria rotundifolia is an evergreen shrub that produces beautiful butter-yellow flowers from December to late summer, and is ideal for those sensitive places you would like to protect from destructive feet, as it produces an attractive thorny barrier.

Description
This spiny, evergreen, rambling shrub grows fairly fast, up to 1 m, with a rounded shape; it produces small, shiny green leaves and yellow tubular flowers from December to March. The four upper lobes of the flower separate from the lower lobe to form an open tube from which 2 stamens and the style protrude. The fruit is a small exploding capsule.

Conservation status
None

Distribution and habitat
Barleria rotundifolia is found in the summer rainfall area of the Lowveld region situated in the eastern parts of South Africa where it grows in well-drained soils throughout rocky hilltops (koppies) and hillsides in full sun to semi-shade and is able to withstand a moderate amount of frost. Rainfall ranges from 500-750 mm per annum with temperatures rising to 30°C.

Derivation of name and historical aspects
The genus name Barleria is derived from the name of a Dominican monk and French botanist, Jacques Barrelier who lived during the 1600s. The species name rotundifolia refers to the round shape of the leaves. The genus consists of a group of herbs or shrubs, some producing spines and all producing fruit in the form of explosive capsules. It is found throughout the warmer parts of Asia, Africa and America. It contains about 250 species of which about 60 occur in South Africa. The genus includes a few other species of note to gardeners, including the white-flowering B. albostellata; B. obtusa with blue-mauve, pink and white flowers; B. greenii; and the rose-pink B. repens.

Ecology
Barleria rotundifolia is pollinated by insects and attracts various species of butterflies. The insects attract insectivorous birds; therefore if you are a gardener that likes attracting life into your garden, this plant is a good choice.

This plant produces seed that is carried in a fruiting body in the form of a small capsule, which explodes when the seed is ripe. It also carries spines to protect itself from being over-grazed by animals.

Uses and cultural aspects
The horticultural value of the Barleria genus has been greatly underrated so far. It is now proving to be a very promising genus, containing many species that would be wonderful additions to any garden.

Growing Barleria rotundifolia

Barleria rotundifolia grows fast and reaches maturity within two years. It can be propagated through seed or from cuttings.

It grows easily from seed. The seed capsules/fruit should be collected as soon as they turn brown. Don't wait too long to collect the capsules otherwise they explode and the seed is harder to collect or lost.

The plants require full sun to semi-shade and should be planted in sandy to loamy soil. Mixing 500 g of compost with 50 g of super-phosphate and working it into the soil will improve growth. A moderate amount of water is required and these plants do rather well in the dry season, thus it is a perfect choice for a water-wise garden. It is semi-frost-resistant and can therefore withstand a certain amount of cold weather, especially if planted in a protected area. It is advisable to prune Barleria rotundifolia after it has flowered.

It can be planted in groups in flowerbeds or in the semi-shade under trees or in clumps on rockeries. It can be used in containers, providing the containers are large and the plants regularly receive additional food and water.

No known pests or diseases are encountered.

References and further reading

• Joffe, P. 2001. Creative gardening with indigenous plants. A South African guide. Briza Publications, Pretoria.
• Leistner, O.A. (ed.). 2000. Seeds plants of southern Africa : families and genera. Strelitzia 10. National Botanical Institute, Pretoria.
• Pooley, E. 1998. A field guide to wild flowers of KwaZulu-Natal and the Eastern Region. Natal Flora Publications Trust, Durban.
• Smith, C.A. 1966. Common names of South African plants. Memoirs of the Botanical Survey of South Africa No. 35.