General Info

Tree may reach 12m high. The simple Leaves lack stipules. White, congested, bisexual, zygomorphic Flowers in racemes + didynamous stamens. Fruit: is a small, fleshy drupe + persistent calyx.

Description

Tree

Volkameria glabra, Clerodendrum glabrum – until 2010, Clerodendrum ovale, Clerodendrum rehmannii.

RSA Tree No. 667.

Common names: Tinderwood, Weeping tree, Cats Whiskers, Bitterblaar, Stinkboom.

Family: Lamiaceae (mint family) has 236 genera and 7 000+ species. Members if this family may have saw-toothed Leaves and may have 4-angled stems. The opposite or whorled leaves are usually simple or digitate. Many are gland-dotted and all lack stipules. Many are aromatic: including lavender and rosemary. Flowers are often Zygomorphic (the corolla is divisible into 2 equal halves in one plane only). There is a superior, 4-locular Ovary. Fruit has up to four 1-seeded nutlets or it is a drupe. Local genera include Tinnea, Vitex and Volkameria.

Name derivation: Volkameria – named after Johann Christoph Volkamer (1644-1720) a botanist, merchant and manufacturer – or it is named after his son. glabrum – somewhat hairless. The genus Volkameria has 20 species which are widespread in southern Africa but absent from the Western and Northern Cape.

Conservation Status: L.C. (Least Concern). 2009.

This densely crowned Tree may reach 10m and occasionally 12m in height. It can also be a multi-stemmed shrub. The Trunk is up to 30cm wide and may branch some distance off the ground. The initially smooth grey-brown Bark becoming roughly fissured or flaking with age. The slender, initially hairy young branches are slightly upright and roughly quadrangular. They have leaf scars and raised visible light lenticels (usually raised corky oval or elongated areas on the plant that allows the uncontrolled interchange of gases with the environment).

Leaves

This semi-deciduous tree has simple, hairless Leaves. They usually in whorls of 3 or are opposite and occur around a node. Leaves are variable, elliptic, elliptic-ovate or lanceolate, up to 10 x 7cm and are usually smooth. They protrude horizontal or are drooping. The Blade is dark green above. Below, the blade is paler green with minute sunken gland dots, a prominent midrib and soft hairs. Net veins are clearly visible below as are the 5-7 pairs of lateral veins. Here sunken gland dots are visible. The Apex tapers to a point and may occasionally be attenuate (showing a long gradual taper). The Base is tapering to rounded and partially running down the petiole. The entire Margin is slightly rolled under. The erect Petiole (leaf stalk) is thin, hairy, up to 2cm long and furrowed on the upper surface. The leaf may be folded up along the midrib. Crushed leaves have a distinct pungent odour (the Venda name “Munukha-tshilongwe” means “smells of cattle dung”). Stipules (basal appendages of the petiole) are absent.

Flowers

The small, more or less actinomorphic (regular, symmetrical. The Perianth – the calyx and corolla are divisible into 3 or more identical sectors or mirror images) Flowers are impressive when large quantities are formed. They are whitish and are produced in terminal heads in leaf axils. Each bisexual flower has a 5-lobed Calyx with a narrowish tube. The Corolla tube is up to 1cm long, widens near the throat and ends in 5 lobes. The anterior lobes are larger than the rest. The hairy white or pale pink lobes are up to 4 x 3mm, with mauve or lilac tinged margins. These lobes bend backwards as they age. There is one deep violet corolla lobe and the other 4 are greenish white. The 4 protruding and curling Stamens are mauve or lilac and are didynamous (having 4 stamens disposed in 2 pairs of 2 different lengths. This arrangement usually occurs in Scrophulariaceae, Labiatae and Stilbaceae). Stamens, with their linear Filaments, arise on the upper part of the corolla tube. The Anther theca (pollen sacs) diverge slightly (photo 525).  The single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma) has a superior Ovary, which is imperfectly 4-locular. The single linear Style also protrudes beyond the petals and curves downwards. The flowers are congested in racemes (simple, indeterminate inflorescences with stalked flowers). These terminal flower heads are up to 14cm in diameter. The upper leaves may almost enclosed the flowers. Flowers are either sweetly or unpleasantly scented (Nov-Apr but may occur most of the year).

Fruit

Fruit is Drupe (a fleshy, 1-seeded indehiscent fruit with the seed enclosed in a stony endocarp; stone fruit e.g. peach) and they develop in dense heads. Each fruit is composed of 4 nutlets (small nuts which are indehiscent, single seeded, hard and bony) enclosed within. The persistent Calyx is ring shaped. This ribbed calyx forms a loose cup surrounding the base. The fruit is almost spherical to slightly lobed up to 10mm in diameter. The fruit is cream to yellow coloured at maturity. The fruits are closely packed into round heads, which may remain on the tree for months (Feb-Jul).

Distribution & Ecology

These Trees are located in deciduous woodland, rocks, termite mounds and forest fringes. They grow well in both open sun and light shade and may be short and deformed on coastal dunes. Found in Eastern Cape, KwaZulu-Natal – from the coast to the Drakensberg, Gauteng, Mpumalanga, Limpopo, Northern Province, Swaziland, Botswana, Zimbabwe, Mozambique Swaziland and northern Namibia. Birds like white-eyes and Layard’s Bulbul eat the fruit. Froghopper or spittlebugs are insects that can jump many times their height. It is their nymphs that suck the sap out of this tree and causes the trees to have a reputation as a rain tree.

Ethnobotany

The Wood is white to pale brown, close-grained, hard and slightly brittle. It is used for hut and fish kraal construction and for small pieces of furniture. The wood may be used as tinderwood (kindling – hence the common name “tinderwood”). This plant is a popular ornamental shrub. The butterfly larva of the Natal Bar (Cigaritis natalensis) feeds on the leaves as do the larva of the Purple-brown Hairstreak / Common Hairstreak (Hypolycaena phillippus). Leaves have been used as insect repellants. In an investigation the hexane extracted from the plant has shown to have a good antifungal activity against Candida albicans. This fungus can cause thrush in the mouth. It can also causes yeast infections. This tree is fast growing and both seeds and cuttings can be used for propagation. New growth can flower after 1 year. This is a popular garden tree.

References

Boon, R. 2010. Pooley’s Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban.

Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of Southern Africa, edn 3. Struik, Cape Town.

Lawrence, G. H. M, 1951. Taxonomy of Vascular Plants, The Macmillan Company, New York. Tenth Printing 1965.

Palmer, E. & Pitman, N. 1972. Trees of southern Africa, Balkema, Amsterdam, Cape Town.

Schmidt, S. Lotter, M. & McCleland, W. 2002. Trees and Shrubs of Mpumalanga and the Kruger National Park.

van Wyk, B. & van Wyk, P. 1997 Field guide to Trees of Southern Africa, Struik, Cape Town.

 

http://www.digplanet.com/wiki/Clerodendrum_glabrum

http://redlist.sanbi.org/search.php?sppsearch=Volkameria+glabra+

http://www.calflora.net/southafrica/plantnamesP-Z.html

http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=149130

http://plantzafrica.com/plantcd/clerodenglab.htm

http://repository.up.ac.za/bitstream/handle/2263/32977/Masevhe%20_Isolation_2013.pdf?sequence=4

https://en.wikipedia.org/wiki/Froghopper

http://posa.sanbi.org/flora/browse.php?src=SP

https://en.wikipedia.org/wiki/Volkameria

https://www.britannica.com/plant/Lamiaceae

https://en.wikipedia.org/wiki/Froghopper