Barleria greenii
Barleria greenii M. & K.Balkwill
Family: Acanthaceae
Common names: wild bush petunia, Green's barleria
Introduction
A beautiful shrub with large pink to white, night-scented flowers in summer.
Description
Description
Barleria greenii is a bushy, much branched shrub up to 1.5 m in height, with robust stems which are woody at the base. The leaves have small hooks at the tips.
The flowers are large and most striking and appear from mid- to late summer. They vary from white to pink and occur in groups in the axils of the leaves. The flower bracts are stiff and spiny. The flowers emit a strong, sweet fragrance at night and produce copious quantities of nectar which attracts bumblebees. Hawk moths have been observed feeding from the flowers at night and are thought to be the pollinators.
Conservation Status
Status
Barleria greenii is a rare species that occurs over a small range and in a very specific habitat. It is assessed as Criticially Endangered (CR) according to the Red List of South African Plants and faces a very high risk of extinction in the wild in the near future. The wild population of this species is declining because the habitat is being degraded and damaged by activities associated with human settlement. It was formerly protected inside the Weenen Nature Reserve and Lowlands East Conservancy. However, the settlments have recently expanded into the protected areas and the impact of this on this species has yet to be realised.
Distribution and habitat
Distribution description
This spectacular shrub is a narrow endemic, naturally occurring in a small area in the Estcourt region of KwaZulu Natal. It has only recently been discovered and was only officially named in 1984.
Barleria greenii is restricted to heavy, black clay soils on doleritic rock. It can be found in open rocky areas and is most abundant in moist areas such as along drainage lines or streams. Although it is very common where it occurs, it is regarded as rare due to highly restricted distribution and specific habitat requirements.
Derivation of name and historical aspects
History
The genus Barleria is named after Jacques Barrelier, 1606-1673, Dominican monk and botanist. This species is named in honour of Dave Green, a farmer and amateur botanist from the Estcourt district in the KwaZulu Natal midlands who discovered the species.
Ecology
Ecology
Barleria greenii is night-scented and is pollinated by moths. It produces copious amounts of nectar that attracts bumble bees. Seed pods explode when ripe, and seeds are expelled by balistic dispersal over relatively short distances from the parent plant. This results in dense but localised populations.
In its natural habitat the plants have to contend with grass fires, which older plants survive and send out new growth afterwards (resprouters). Plants that are burned frequently are well-branched and rarely up to 1 m tall, whereas those that are burned less frequently are robust and woody and reach almost 2 m in height. Seedlings and young plants do not survive the fires.
Uses
Use
There are no known cutural or traditional uses for Barleria greenii.
Growing Barleria greenii
Grow
Barleria greenii makes a beautiful garden subject as it flowers so prolifically. It grows under a wide range of conditions and is frost hardy. Plants are easily propagated by tip cuttings or from seeds. Once established, seedlings should flower within 18 months. Pruning back in late winter or early spring will encourage prolific flowering and dense, bushy growth. In the winter rainfal areas it requires watering during summer.
References
- Pooley, E. 1998. A field guide to wild flowers Kwazulu-Natal and the eastern region. Natal Flora Publications Trust, Durban.
- Scott-Shaw, C.R., Johnson, I.M., Styles, D., Makholela, T. & von Staden, L. 2007. Barleria greenii M.Balkwill & K.Balkwill. National Assessment: Red List of South African Plants version 2015.1. Accessed on 2016/09/15
Credits
Sharon Turner
Walter Sisulu National Botanical Garden
March 2001
updated by Alice Notten
Kirstenbosch National Botanical Garden
September 2016
Plant Attributes:
Plant Type: Shrub
SA Distribution: KwaZulu-Natal
Soil type: Sandy, Clay, Loam
Flowering season: Late Summer
PH: Acid, Neutral
Flower colour: White, Pink
Aspect: Full Sun, Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Average
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