General Info – summary.

This attractive unarmed Plant is up to 2+m high. Arching branches are covered with white hairs. This usually evergreen plant has opposite simple Leaves with entire margins. The snowy white, bisexual, zygomorphic Flowers are in cymes with 1+4 white petals and 2 fertile stamens. Superior ovary has 1-2 ovules. Fruit: small, sessile, explosively dehiscent capsule, with soft seeds covered with hygroscopic hairs.

Description.

Barleria albostellata.

Common names: (Afr) Bosviooltjie, Grysbarleria. (Eng) Grey Barleria.

Family: Acanthaceae. (The Acanthus family). This family has about 230 genera and 4 000 species. In southern Africa, there are about 42 genera and 350 species. All members have simple Leaves without stipules. They are mostly entire. Inflorescences are mostly bracteate – subtending each flower. The Flowers are usually zygomorphic, bisexual with a nectariferous disc. The calyx usually shorter than the gamopetalous corolla, which has 1-2 lips. 4 Stamens arising on the corolla are usually present. The superior 2-locular Ovary contains a large embryo. Fruit is 2-locular and Seeds lack endosperm. Local genera on this website include Barleria, Justicia and Mackaya.

Name derivation: Barleria – after the French Botanists Jacques Barrelier (1603-1673). albostellata – albo – white (flowers); stellata – star-like – referring to the hairs. In this genus, there are about 250 species, of which about 60 species occur in southern Africa.

Conservation Status: L C (Least Concern). Assessed: 2006 (D. A. Kamundi).

Plant

This attractive Plant (photo 963) is unarmed and usually is a medium to large multi-stemmed shrub, which under ideal conditions, may reach 2+m high. White hairs cover the arching, slender Branches.

: 963 2017.11.17 Pretoria NBG. Photo: David Becking.

Leaves

This is usually an evergreen plant, but Leaves may be lost in cold weather. They are simple (have a single blade, which may have incisions that are not deep enough to divide the leaf into leaflets). Leaves are opposite, broadly ovate (shape of an egg) and each leaf is up to 14 x 8cm (photo 679). The Margin is entire (with a continuous margin, not in any way indented – photo 672). Leaves are velvety grey-green on both surfaces but lighter on the lower surface (photo 679) and here the Midrib and Lateral veins protrude. On the upper surface, the veins are sunken. The Apex is pointed, and the Base is broadly tapering or rounded. It might be slightly decurrent (leaf blades that partly wrap or have wings around the stem or petiole (photo 672). The hairy petiole is up to 3cm long and grooved on the upper surface (photo 679). There are usually 2 Serial Buds in leaf axils, the upper bud producing a normal branch or a single inflorescence and the lower bud producing a branch or vegetative spine system.

: 672 2017.01.31. Pretoria NBG. Photo: David Becking.

: 679 2107.01.31 Pretoria NBG. Photo: David Becking.

Flowers

The snow-white, shortly trumpet shaped Flowers are attractive and similar to those in Mackaya bella. They appear sporadically from spring to late summer. The inflorescence is a cyme (a broad, more or less flat-topped, determinate flower cluster, with central flowers opening first) with 2-4 flowers at branch ends. Single flowers also occur. Flowers are bisexual and zygomorphic (irregular flower with the corolla is divisible into 2 equal halves in one plane only) surrounded by 4 leafy, purple-tinged bracts (photo 667). (Bracts are modified specialised leaves usually found with inflorescences and flowers. They may be different from “normal” leaves – bigger or smaller, different shape and colour. They may occur in whorls). These hairy bracts resemble a spider’s nest. The Disc (a more or less fleshy or elevated development of the receptacle) is deeply cup shaped. The Calyx is irregular with 4 lobes. The 2 large outer lobes are abaxial (facing away from the stem; lower surface of leaf) and the inner lobes are lateral and small. The thin (photo 171) tubular Corolla is irregular and gamopetalous (with united joined petals – at least at the base). There are usually 2 fertile Stamens (photo 171) inserted on the corolla. These 2 stamens are not didynamous (having 4 stamens disposed in 2 pairs of 2 different lengths). The Filaments may be long, are often twisted, and cross over each other. The Anthers are basifixed (photo 678) and they dehisce longitudinally. The 2 theca – pollen sacs are initially visible (photo 678) but far less so once the pollen is being shed (photo 171E). At this later stage, the released pollen is visible. The 2-locular superior Ovary has 1 or 2 ovules in each Locule. The exserted Style (here extending beyond the perianth) is terete (circular in cross-section – photo 171). (Sep-Feb).

: 671 2017.01.31 Pretoria NBG. Photo: David Becking.

: 677 2017.01.31. Pretoria NBG. Photo: David Becking.

: 171 2018.03.14 Pretoria NBG. Photo: David Becking.

: 673 2017.01.31 Pretoria NBG. Photo: David Becking.

: 678 2017.01. 31 Pretoria NBG. Photo: David Becking.

: 171E 2018.03.14 Pretoria NBG. Photo: David Becking.

Fruit

The small, explosively dehiscent and stalkless Fruit is a Capsule (a dry fruit resulting from the maturing of a compound ovary, which usually opens at maturity by one or more lines of dehiscence). In this plant, it may have a beak. Seeds are soft with hygroscopic (tending to absorb moisture from the air) hairs over the whole surface. (Autumn-Winter).

Distribution & Ecology

These plants occur naturally in the Limpopo and Zimbabwe – in riverine thickets, rocky woodland and well-drained soils. They grow best in full sun – usually below 1 500m. Pollinating agents are insects – including butterflies and these insects attract birds. The plant reaches maturity after about 3 years.

Ethnobotany

This attractive garden plant is slightly drought and cold resistant. Propagation is by seeds or cuttings and within 3 years, the plant reaches maturity. Plants grow best in moist soil in full sun or semi shade. The plant attracts insects and birds. Pruning will enhance appearance.