For the identification of insects and other fauna and flora of South Africa.

Monday, April 29, 2013

Kudu Lily (Pachypodium Saundersii)

Family Apocynaceae
 P. saundersii is a succulent shrub with a large stem up to 1.5 m high. The exposed tuberous stem is up to 1 m in diameter and produces several narrow, thorny branches.
 The flowers are white, wax-like, tinged purplish pink and are borne from February to May. The glossy leaves are almost glabrous.
 It naturally occurs from northern KwaZulu-Natal and the Lebombo Range into Mpumalanga and Limpopo Provinces ( South Africa ) to Swaziland, southern Mozambique and Zimbabwe.
 This species grows in dry woodland amongst rocks or in rock crevices. The epithet honours Sir Charles James Renault Saunders.

Saturday, April 27, 2013

Red Candelabra Flower (Brunsvigia grandiflora)

Family Amaryllidaceae
(I could not find information about this flower in particular, only the species in general)

The sheer exuberance of brunsvigias flowering en masse is a natural spectacle that should not be missed.


Description

The name Brunsvigia was first published in 1755 by Lorenz Heisters (1683-1758), a botanist and professor of medicine at the University of Helmstädt. It honours Karl, the Sovereign of Braunschweig, who promoted the study of plants, including the beautiful Cape species B. orientalis.

Brunsvigias are deciduous, temperate, bulbous plants. Most species have subterranean bulbs but they are usually half-exposed in B. herrei and B. josephinae. The bulb tunics are typically brittle and tan-coloured, although they are brown and papery in B. josephinae and B. litoralis.
When mature, the leaves are broad and oblong to tongue-shaped. In species with small bulbs- B. radula , B comptonii and B. namaquana -there are just two or three leaves per plant but most other species have at least four leaves per bulb. B. josephinae has the distinction of producing as many as 20 leaves. The leaves mostly lie flat on the ground and sometimes press down so firmly that they lie vertically if the bulb is dug up. Only in B. litoralis , B. josephinae , B. grandiflora, B. undulata and B. herrei do the leaves stand clear of the ground. Although usually smooth, the upper leaf surfaces of two Namaqualand species ( B. radula and B. namaquana ) are covered with straw-coloured bristles and in some populations of B. striata from the southern Cape, they bear soft, scale-like hairs. In the winter rainfall region of southern Africa, the foliage is produced after the flowering heads have been shed, whereas in the summer rainfall region the vegetative and flowering stages often overlap.
  The inflorescences are extremely eye-catching. In most species the pedicels are straight and radiate outwards to form an almost perfectly spherical head. However, B. litoralis , B. josephinae and B. orientalis differ in having pedicels that curve below each flower. Just three species ( B. pulchra, B. marginata and B. elandsmontana ) have compact, brush-like inflorescences. The flowers vary from ruby-red to brilliant scarlet or pale to bright pink and in some species the entire inflorescence is attractively coloured. When in flower, the plants are spectacular but the flowering period is brief and restricted to summer and autumn. Pink flowers are the norm, whereas red flowers are found in B . marginata , B. orientalis, B.litoralis and B. josephinae. Floral markings are often variable within species but dark veins on the tepals are characteristic for B. bosmaniae and B. gregaria.
The six tepals of each flower are free to the base or shortly fused into a tube. Radially symmetrical, trumpet-shaped flowers occur in species with compact, dense inflorescences, whereas bilaterally symmetrical flowers occur in species with open, lax heads. In B. comptonii , B. radula and B . namaquana, the flowers are highly asymmetrical as all but one tepal curve upwards. Often the flowers are scented and all produce nectar.

The water-rich, non-dormant seeds are borne in dry capsules that are spindle-shaped or three-angled and often heavily ribbed.

Today only B. litoralis is endangered due to housing developments overtaking its coastal habitat between Cape St Francis and Port Elizabeth.

  
Distribution

Brunsvigia has about 20 species in total and is widespread in southern Africa, mostly in the semi-arid areas. More than half the species are found in the winter rainfall region but several species are also found along the Drakensberg, KwaZulu-Natal, in the summer rainfall region.

Species range from the coast to the inland escarpment. Some favour specific substrates like quartzite veins, dolomite outcrops, shale bands and sandy plains. Only a few occupy seasonally damp depressions, mainly in the eastern summer rainfall region. Most species are widespread but a small number ( B . elandsmontana, B. herrei, B. namaquana, B. pulchra, B. radula, B. striata and B. undulata ) are naturally rare.

 Ecology

The flowering heads function highly effectively to attract pollinators and to disperse seeds. The pollination ecology of the genus as a whole is poorly understood, despite what is known about the diverse pollination strategies of the winter rainfall species. At dusk noctuid moths pollinate the trumpet-shaped, pink flowers of B. bosmaniae . During the day the big, brown butterfly, Aeropetes tulbaghia , which is commonly known as the Pride of Table Mountain, visits the brilliant red flower clusters of B. marginata . Other day visitors are sunbirds that feed on the nectar of the red, somewhat tubular flowers of B. josephinae, B. litoralis and B. orientalis . Anyone who has seen the ease with which malachite and Lesser double-collared sunbirds perch on the pedicels and probe the flowers will appreciate how perfectly these species are suited to bird pollination.

Once dry, the light, spherical, fruiting heads break loose from the bulb. The triangular-shaped capsules of many species are reminiscent of small kites, which enable the heads to tumble across the ground in the wind. In so doing, the capsules break open and scatter their seeds. [See picture in Amaryllidaceae]

Economic and cultural value

In southern Africa, the bulbs of Brunsvigia are traditionally used as decoctions to enhance the accuracy of the dice thrown by local diviners. Otherwise infusions of the bulbs are used for medicinal purposes. Like all Amaryllidaceae, however, brunsvigias are rich in alkaloids that can be extremely toxic.

Thursday, April 25, 2013

Everlasting (Syncarpha recurvata)

Family Asteraceae
Common names : there are no common names known for Syncarpha recurvata, but Syncarpha species in general are known as “ sewejaartjies ” (little seven-years) in Afrikaans, indicating that the flowers last for a long time, and echoing the English common name, everlasting which is applied to many different species that last well as dried ornamental cut-flowers.

Syncarpha recurvata is a small, shrubby daisy with pretty pink flowerheads and attractive silvery foliage. This low shrub is endemic to a small area in the Eastern Cape. Unfortunately, its habitat is under threat and this beautiful little everlasting is fast losing the only places where it can exist naturally.
Description
The plant is a low, well-branched shrub that forms small bushes in scrub on calcareous ridges. Stems are robust and about 120–300 mm high. The leaves are narrow and green and are curved backwards and covered in silky hairs, giving them a silvery appearance.

During the flowering period the bushes are topped by small but striking hemispherical flowerheads. The flowers are tiny and yellow and are borne in rounded heads surrounded by dry, shiny, spreading pink bracts that become silvery with age. Each plant produces a fairly large number of flowerheads, forming an attractive display. The main flowering period appears to be early summer, but plants can be found in flower in April and other months.

 Conservation status

This species is listed as Endangered according to the SANBI Red List (http://redlist.sanbi.org) . At the time of assessment, eight severely fragmented subpopulations were thought to remain, and these were in decline due to calcrete mining for cement production, urban expansion and alien plant invasion. Exploitation as everlasting cut-flowers may also pose a threat in populations that are easily accessible.

Conservation through relocation is the focus of ongoing studies by E.E.Campbell and students at the Nelson Mandela Metropolitan University.

Distribution and habitat

Syncarpha recurvata occurs in low-lying areas (from sea level up to 200 m altitude) in the Bontveld of the Eastern Cape. This vegetation covers only 500 km 2 and consists of a mosaic of bushclumps and grassveld. Within the Bontveld, S. recurvata is confined to shallow calcareous sands on calcrete ridges .

The climate in this area is oceanic, with mild cool winters and warm summers, and some degree of humidity. The temperature range is small, and so the plant might not tolerate frost. In addition, in its natural habitat S. recurvata does not experience a dry season, as precipitation is distributed throughout the year. Rainfall is, however, greater and more frequent during the winter months.

 Derivation of name and historical aspects

Syncarpha is a genus of 28 species endemic to the Cape Floristic Region. In Greek, syn means united and carphos , any small dry body; it is thought that the generic name might refer to the dry bracts which are united into a cone-like structure surrounding the flowerheads. The specific name, recurvata , refers to the leaves which are bent backwards (recurved). Several Syncarpha species are very showy and are attractive horticultural plants in indigenous gardens (for example, S. argentea and S. vestita ). S. eximia (strawberry everlasting) is not cultivated but is an extremely striking member of the genus . S. vestita is known as ‘Cape snow' and is a popular nature photography subject.

Ecology

Little is known of the ecological interactions of Syncarpha recurvata . The beautiful flowerheads are likely to play a role in attracting an animal pollinator, but no record exists of who this pollinator might be.

Syncarpha seeds (called achenes or cypselae) are small and light and bear a crown of feathery hairs (called a pappus ) which is likely to aid in wind dispersal.

Syncarpha recurvata is highly specialized on a unique soil type which consists of ancient marine sediments compacted to form soft calcrete. This habitat-specificity is likely to be one of the factors that limits its distribution range, confining it to small areas where this soil type is exposed.

 Uses and cultural aspects
The flowerheads of Syncarpha recurvata are exceptionally attractive and are commonly used as ornamental cut-flowers by members of the public. Since the colourful parts of the flowerhead consist of dry, papery bracts, they make good everlasting displays together with dried grasses.

Tuesday, April 23, 2013

Porkbush/Vetplant (Portulacaria afra)

Family Portulaceae
Portulacaria afra or porkbush is a popular succulent garden plant in use around the world and is often used for bonsai. It has now been shown to be effective in carbon sequestration (binding atmospheric carbon which is responsible for climate change), in semi-arid landscapes and thicket vegetation it is also being used for restoration purposes.
 Derivation of name and historical aspects

The name Portulacaria is composed of Portulaca + aria suggesting a similarity to the genus Portulaca. The word afra is in reference to the fact that the plant occurs in Africa.

The porkbush belongs to a large and widespread family (Portulacaceae) which includes the popular Portulaca and is often sold in garden centres and grown in domestic gardens as an annual for summer colour, although this is not a South African species. Other members of this genus include Portulacaria armiana and Portulacaria pygmaea the former has larger grey green leaves and is native to Namibia although it is not often cultivated, whereas the latter is a dwarf succulent shrublet with small, thickly fleshy, grey green leaves and occurs on rocky hillsides in Namaqualand, South Africa.

 Description

The porkbush is an attractive, evergreen succulent shrub or small tree that can reach 2 - 5 m in height, although usually around 1.5 - 2 m in a garden situation. It has small round succulent leaves and red stems. Small star-shaped pink flowers are borne en masse from late winter to spring although flowering in cultivation is often erratic. They are a rich source of nectar for many insects, which in-turn attracts insectivorous birds.

Distribution

It is found in warm situations on rocky slopes in succulent karoo scrub, thicket, bushveld and dry river valleys in the eastern parts of South Africa from the Eastern Cape northwards into KwaZulu-Natal, Swaziland, Mpumalanga and the Limpopo Province as well as Mozambique.

Conservation status
Portlulacaria afra is listed in the National Red Data List as Least Concern which indicates that it is not threatened in its natural habitat.

 Ecology

Interesting ecology has been observed with this plant in the Eastern Cape where it forms part of the diet of the Addo elephants in the Addo National Park. Elephants eat the plant from the top downwards allowing the plant to spread itself vegetatively by spreading horizontal branches at ground level. Outside the park the plants are eaten by goats who eat the plant from ground level upwards preventing the plant from spreading vegetatively. Consequently these plants must rely solely on seed to proliferate the species which often proves difficult in such a dry climate. As a result it was observed that inside the park where the plant is subjected to browsing by elephants the pork bush survives and spreads successfully whereas outside the park the plant is becoming sparse as a result of overgrazing and poor regeneration. A very interesting mistletoe, Viscum crassulae, parasitizes this plant. The foliage of this mistletoe is hard and rough in contrast to the soft and smooth leaves of the porkbush. The small red fruits of the mistletoe are enjoyed by birds who eat the sweet outer layer and discard the sticky seed which is normally wiped onto a branch by the bird. There it germinates directly through the bark of the porkbush with specialized roots called haustoria which extract moisture and soil nutrients from the host, while the green leaves allow the semi-parasitic mistletoe to produce its own food.

Uses & cultural aspects

The leaves of the porkbush can be eaten and have a sour or tart flavour. It is heavily browsed by game and domestic stock and highly favoured by tortoises. The porkbush has also been indicated as a soil binder for preventing soil erosion. Traditional uses also include the increasing of breast milk by lactating mothers. The leaves are used to quench thirst, sucking a leaf is used to treat exhaustion, dehydration and heat stroke. Crushed leaves can be rubbed on blisters and corns on the feet to provide relief. The leaves are chewed as a treatment for sore throat and mouth infections while the astringent juice is used for soothing ailments of the skin such as pimples, rashes and insect stings. The juice is also used as an antiseptic and as a treatment for sunburn. It is also recorded that a small sprig of porkbush steamed with a tomato bredie (stew) imparts a delicious flavour. The honey made from the flowers of porkbush is said to be " unsurpassable in flavour and texture" by one reference (Roberts 1990).

The Porkbush on Climate Change

Recent research has shown the Porkbush to be an excellent 'carbon sponge' as it has the ability to sequestrate (absorb) free carbon from the atmosphere which is used to make plant tissue. Carbon is one of the major greenhouse gases which are responsible for the warming of the earth's atmosphere; it is produced in excess by burning of fossil fuels. Currently, humans are producing atmospheric carbon faster than the environment can absorb it, causing a deficit which remains in the atmosphere and causes heat from the sun to be trapped instead of being radiated back out into space. The porkbush has the unique ability to absorb more carbon from the atmosphere than most other plants and it does so particularly efficiently. A stand of Pork bush consequently has the ability to remove more carbon from the atmosphere than an equal amount of deciduous forest.

How does it manage this? The porkbush has the ability to make use of two different photosynthetic pathways, when conditions are favourable it manufactures its food to sustain growth by using the same method (pathway) that most other plants use. However, when conditions are not favourable and other plants have to shutdown and wait for sufficient rain, the porkbush can switch to a different pathway called CAM (Crassulacean Acid Metabolism) whereby it can continue to grow and slurp up huge amounts of carbon despite adverse climatic conditions. This allows the plant to excel in the arid or semi-arid conditions that it is native to.

Further to its carbon habit, the large spreading shrub covers and shades the soil from the harmful rays of the sun creating a favourable environment under the bush for insects and other wildlife to inhabit, while the dead organic matter which accumulates under the bushes has an enriching effect on the soil. This further enrichment of the soil improves its water-holding capacity which further benefits the porkbush as well as other plants and animals including micro-organisms, which occur in the area.

Projects now active in the areas where the porkbush occurs seek to utilize it as a rehabilitation aid to restore over-utilized natural habitats to their formerly productive state. At the same time these sites act as carbon sinks (kind of carbon bank) where carbon can be collected and used where it belongs and is productive to both humans and the environment. Potential earnings through carbon credits could be translated into social upliftment in the areas where this plant is being utilized.

Sunday, April 21, 2013

Torchwood/Greenthorn (Balanites maughamii)

Family Balanitaceae
The common name, torchwood, has been derived because the dry kernels have been burnt as torches.

Balanites maughamii is not well known in South Africa . The older trees have an amazing, upright, deeply folded or buttressed trunk, that visually singles them out from other trees (see photograph above taken in the Pretoria National Botanical Garden by Mrs L. Ferreira). This ensures that the tree can be identified from its trunk alone.
 Description

The torchwood is a medium to large upright tree, 10-20 m high. It is deciduous to semi-deciduous. It typically has a spreading crown and the older trunks are greyish. The branchlets are greyish green and hairy. Usually the zigzag branchlets are strongly armed with unequally forked spines forming a y-shape, sometimes simple; or they are unarmed, usually the fruit-bearing branches, sometimes with very small spines.

Leaves are leathery with velvety hairs when young, grey-green, alternatively arranged, compound, with two elliptic to ovate to round leaflets; the margin is entire, the apex is rounded and the base tapering. The central vein of the leaf is slightly off-centre and the base is unequal.

Flowers are borne in small clusters in leaf axils, are star-shaped, small, bisexual, scented, greenish yellow, hairy above and smooth below. The flowers have 5 sepals and petals, 10 stamens and the ovary is 5-chambered with one seed in each chamber. Flowering time: from July to November.

The brownish yellow fruit is a thin, fleshy oval drupe, 30-60 x 20-30 mm, usually distinctly grooved. The bitter flesh covers a large, hard, stone kernel. The fruit is ripens between May and July.

Distribution
The plants can be found in small colonies in the bushveld, sand forest, on sandstone outcrops, along river banks, near springs and around pans.

Name derivation

The genus Balanites was derived from a Greek word meaning acorn-shaped. The species d maughamii was named in honour of R.C.F. Maugham, the British Consul at Lourenco Marques (now Maputu), who sent specimens of this tree to Kew in 1911.

 Ecological value

Elephants have been seen browsing the tips of the branches. The fleshy part of the fruit is eaten by humans and a variety of animals such as monkeys, baboons, warthogs and antelope. Mr Erich van Wyk of SANBI has reported that he found seed in cattle droppings and t this seed germinated very well in Millennium Seed Bank trials.

 Uses and economic value

This plant has medicinal value as well as other uses. The roots are used as an enema. The green fruit yields a powerful poison lethal to some fish, tadpoles and snails when placed in the water. The poison may occur in the in the kernel and pulp. It is harmless to people. African people use the tree for magical purposes. Zulu witchdoctors use the roots and bark, together with other plants that have been soaked in water and beaten to a froth to ward off evil spirits (Palmer & Pittman 1972). Because of its excellent lubricative qualities, the Zulus soak the bark in the water for a refreshing bath.


The fruit also yields good colourless oil that burns well and gives a bright flame.


The hard timber has been used to make wooden bowls, panga handles and stocks for guns. Info: http://www.plantzafrica.com/

Saturday, April 20, 2013

Kenaf (Hibiscus cannabinus)

Family Malvaceae
Kenaf [etymology: Persian], Hibiscus cannabinus, is a plant in the Malvaceae family. Hibiscus cannabinus is in the genus Hibiscus and is probably native to southern Asia, though its exact natural origin is unknown. The name also applies to the fibre obtained from this plant. Kenaf is one of the allied fibres of jute and shows similar characteristics.


It is an annual or biennial herbaceous plant (rarely a short-lived perennial) growing to 1.5-3.5 m tall with a woody base. The stems are 1–2 cm diameter, often but not always branched. The leaves are 10–15 cm long, variable in shape, with leaves near the base of the stems being deeply lobed with 3-7 lobes, while leaves near the top of the stem are shallowly lobed or unlobed lanceolate. The flowers are 8–15 cm diameter, white, yellow, or purple; when white or yellow, the centre is still dark purple. The fruit is a capsule 2 cm diameter, containing several seeds.

Fibre

The fibres in kenaf are found in the bast (bark) and core (wood). The bast constitutes 40% of the plant. These fibres are long (2 – 6 mm) and slender. The cell wall is thick (6.3 µm). The core is about 60% of the plant and has thick (ø 38 µm) but short (0.5 mm) and thin walled (3 µm) fibres. Since the paper pulp is produced from the whole stem, the fibre distribution is bimodal. The pulp quality is similar to hardwood.

 Uses

Kenaf is cultivated for its fibre in India, Bangladesh, United States of America, Indonesia, Malaysia, South Africa, Viet Nam, Thailand, parts of Africa, and to a small extent in southeast Europe. The stems produce two types of fibre, a coarser fibre in the outer layer (bast fibre), and a finer fibre in the core. It matures in 100 to 200 days. Kenaf was grown in Egypt over 3000 years ago. The kenaf leaves were consumed in human and animal diets, the bast fibre was used for bags, cordage, and the sails for Egyptian boats. This crop was not introduced into southern Europe until the early 1900s. Today, principal farming areas are China, India, and it is also grown in many other countries such as the US, Mexico and Senegal.

The main uses of kenaf fibre have been rope, twine, coarse cloth (similar to that made from jute), and paper. In California, Texas, Louisiana and Mississippi 3,200 acres (13 km²) of kenaf were grown in 1992, most of which was used for animal bedding and feed.

Uses of kenaf fibre include engineered wood, insulation, clothing-grade cloth, soil-less potting mixes, animal bedding, packing material, and material that absorbs oil and liquids. It is also useful as cut bast fibre for blending with resins for plastic composites, as a drilling fluid loss preventative for oil drilling muds, for a seeded hydromulch for erosion control. Kenaf can be made into various types of environmental mats, such as seeded grass mats for instant lawns and moldable mats for manufactured parts and containers. Panasonic has set up a plant in Malaysia to manufacture kenaf fibre boards and export them to Japan.

Additionally, as part of its overall effort to make vehicles more sustainable, Ford is making the material inside the door – known as the bolster – in part from kenaf. The first implementation of kenaf within a Ford vehicle will be in the 2013 Ford Escape.

The use of kenaf is anticipated to offset 300,000 pounds of oil-based resin per year in North America and reduces the weight of the door bolsters by 25 percent. Weight savings translate into fuel savings for drivers.
 Kenaf seed oil

Kenaf seeds yield an edible vegetable oil. The kenaf seed oil is also used for cosmetics, industrial lubricants and for biofuel production. Kenaf oil is high in omega polyunsaturated fatty acids (PUFAs) which are now known to help in keeping humans healthy. Kenaf seed oil contains a high percentage of linoleic acid (Omega-6) a polyunsaturated fatty acid (PUFA). Linoleic acid (C18:2) is the dominant PUFA, followed by oleic acid (C18:1). Alpha-linolenic acid (C18:3) is present in 2 to 4 percent. The PUFAs are essential fatty acids for normal growth and health. Furthermore, they are important for reducing cholesterol and heart diseases.

Kenaf Seed oil is 20.4% of the total seed weight which is similar to cotton seed. Kenaf Edible Seed Oil Contains:

• Palmitic acid: 19.1%

• Oleic acid: 28.0% (Omega-9)

• Linoleic acid: 45% (Omega-6)

• Stearic acid: 3.0%

• Alpha-linolenic acid: 3% (Omega-3)

 Kenaf paper

The most common process to make kenaf paper is using soda pulping before processing the obtained pulp in a paper machine.

The use of kenaf in paper production offers various environmental advantages over producing paper from trees. In 1960, the USDA surveyed more than 500 plants and selected kenaf as the most promising source of tree-free newsprint. In 1970, kenaf newsprint produced in the International Paper Company's mill in Pine Bluff, Arkansas, was successfully used by six U.S. newspapers. Printing and writing paper made from the fibrous kenaf plant has been offered in the United States since 1992. Again in 1987, a Canadian mill produced 13 rolls of kenaf newsprint which were used by four U.S. newspapers to print experimental issues. They found that kenaf newsprint made for stronger, brighter and cleaner pages than standard pine paper with less detriment to the environment. Due partly to kenaf fibres being naturally whiter than tree pulp, less bleaching is required to create a brighter sheet of paper. Hydrogen peroxide, an environmentally-safe bleaching agent that does not create dioxin, has been used with much success in the bleaching of kenaf.

Various reports suggest that the energy requirements for producing pulp from kenaf are about 20 percent less than those for wood pulp, mostly due to the lower lignin content of kenaf. Many of the facilities that now process Southern pine for paper use can be converted to accommodate kenaf.

An area of 1-acre (4,000 m2) of kenaf produces 5 to 8 tons of raw plant bast and core fibre in a single growing season. In contrast, 1-acre (4,000 m2) of forest (in the US) produces approximately 1.5 to 3.5 tons of usable fibre per year. It is estimated that growing kenaf on 5,000 acres (20 km²) can produce enough pulp to supply a paper plant having a capacity of 200 tons per day. Over 20 years, 1-acre (4,000 m2) of farmland can produce 10 to 20 times the amount of fiber that 1-acre (4,000 m2) of Southern pine can produce.

As one of the world's important natural fibres, kenaf is covered by the International Year of Natural Fibres 2009. The first novel to be published using 100% kenaf paper was The Land of Debris and the Home of Alfredo by Kenn Amdahl (1997, Clearwater Publishing Company).

David Brower, former Executive Director of the Sierra Club, in chapter 8 of his semi-autobiographical environmental book "Let the Mountains Talk, Let the Rivers Run: A Call to Save the Earth" (1995, Harper Collins), titled "Forest Revolution," advocated for kenaf paper use and explained its many advantages over wood pulp. The first edition of the book was printed on kenaf paper.

Pesticide and fertilizer use in kenaf crops

Kenaf is considered a hardy plant that requires a minimum of fertilizers, pesticides and water in comparison to conventional row crops.

Friday, April 19, 2013

Bush Violet (Barleria obtuse)

Family Acanthaceae
Amongst the attractive red, bronze tints provided by tree foliage in autum, Barleria obtusa makes an even more spectacular show. This evergreen flowering shrublet is covered in a mass of dainty violet flowers from April to May. This fast growing, spreading shrublet is a must for rockeries and small gardens.
B.obtusa occurs naturally from the Soutpansberg in the Northern Province, Mpumalanga, and KwaZulu Natal and further to the Eastern Cape Province. It grows quite commonly on hills and along forest margins in subtropical regions.

Barleria obtusa is multi-stemmed shrublet. The branches have an erect or decumbent habit. The size of the plant varies when planted in different growing environments. From about one metre as a low bushy plant in the open, whilst shady conditions encourage long sprawling branches which reach a height of two metres.
The soft, sage green leaves are oppositely placed and have entire margins with fine translucent hairs. A characteristic feature is that the leaves are reflexed (the margins are upturned). In its natural habit the leaves of the bush violet are browsed by buck.
The 2-3cm wide flower petals are borne on the top part of the branch. A closer look at the individual flower will reveal the style and only two stamens with violet coloured pollen. The seed capsule becomes woody when mature, and then the seeds are explosively released and scattered on the ground.

Wednesday, April 17, 2013

Toad Tree (Tabernaemontana elegans)

Family Apocynaceae
Tabernaemontana elegans is a beautiful bushveld tree that can be recognised by its large, glossy leaves, fragrant white flowers and large fruit borne in pairs.


Description

An unarmed shrub or tree mostly 1.5 to 5 m tall but occasionally reaching 12 m. The trunk is 50 to 300 mm thick with a corky, pale brown bark with longitudinal fissures. Twigs have prominent leaf scars that form transverse ridges. The leaves are leathery, opposite and dark glossy green above and paler beneath. Leaf dimensions vary from 90 to 200 mm by 50 to 70 mm; generally 2 to 4 times as long as wide. The petioles are 10 to 25 mm long. The raised midrib and lateral nerves are particularly visible on the underside of the leaf.
 Each inflorescence consists of many white, fragrant flowers and is borne on a 30 to 50 mm-long peduncle. Each flower is up to 15 mm wide and is borne on a 4 to 7 mm-long pedicel. The fruit are in pairs, subglobose, with a green skin that is covered in pale warts. Each fruit is 60 to 70 mm long by 40 to 50 mm wide, with two lateral ridges and one dorsal ridge. The fruit are leathery to woody, with a wall that is 5 to 15 mm thick. When mature, they split open along one side, often while still on the tree, displaying the yellowish pulp inside. Each fruit with its green, warty skin resembles a toad, giving rise to the common name toad tree. Embedded in the yellow pulp are numerous dark brown seeds 14 to 17 mm long by 7 to 9 mm wide.All parts of the plant are hairless and have a milky sap.
 Distribution and habitat

It is indigenous to tropical east Africa through to South Africa and Swaziland. It is most commonly encountered along riverbanks, in coastal forest and savanna woodlands.

Conservation status

Tabernaemontana elegans is not threatened in any way.

Derivation of name and historical aspects

Jakob Theodor von Bergzabern was a 16th century herbalist who Latinised his name as Tabernaemontanus. Linnaeus named this genus after him. The specific name elegans refers to the tree's elegant appearance.

 Ecology

Tabernaemotanus elegans is deciduous, losing most of its leaves during the winter. The yellow pulp from the fruit is eaten by people, monkeys, baboons, rhinoceroses, hornbills and white-eared barbets. Flowering time is October to February.
 Seeds of T. elegans germinate readily, and it is a relatively quick-growing plant. It forms part of the early successional vegetation in subtropical bushveld and coastal forest along southern Africa's east coast. It has been recorded among the weedy shrubs that are first to colonise untended cotton fields in Mozambique.
 Uses and cultural aspects

Apart from the yellow pulp being eaten on its own, the Zulu people add it to milk to speed up the curdling process. The seeds are also burnt, ground to a powder and mixed with tobacco for chewing or smoking. As a medicinal plant it has a variety of uses. The coagulated milky sap is used as a styptic, and root infusions are drunk as an aphrodisiac as well as a remedy for lung ailments and stomach ache. In addition, a maceration of the roots is taken twice daily to treat tuberculosis. Some venereal diseases are treated with a potpourri of plant material that includes roots of Tabernaemontana elegans. The inner layer of the fruit wall (endocarp) is dried, pulverised and boiled in water. The water is then filtered and taken to treat cancer. Please note that parts of the plant, as administered by traditional healers in their concoctions, have been recorded as toxic.
Info: http://www.plantzafrica.com/

Monday, April 15, 2013

River Euphorbia (Euphorbia triangularis)

Family Euphorbiaceae
 As with all Euphorbia, the latex (sap) is poisonous and should especially not get into your eyes as it can cause blindness.

Saturday, April 13, 2013

Oldwood (Leucosidea sericea)

Family Rosaceae
This is a small tree of great character which grows in the eastern parts of South Africa. It is a very versatile addition to the indigenous garden.


The generic name (Leucosidea) is derived from the Greek words for "white or grey appearance", while the species name (sericea) is the Latin for "silky" in reference to the silky hairs on the leaves of the tree.

 The ouhout is often a straggly shrub or a dense, small, evergreen tree, which grows up to 7m tall to 5m wide. It is single or multi-stemmed and branches low down. The bark is rough, reddish brown in colour and flakes off to reveal a smooth light brown under-bark. The leaves are alternately arranged, compound and covered with silky, silver hairs. Each leaf possesses 3 to 4 pairs of leaflets. The veins on the leaves are deeply sunken on the upper surface and protrude on the lower surface. The leaves are a dark green colour above and a lighter green colour below. The margins of the leaflets are deeply serrated. When the leaves are crushed they have a strong herb-like smell. The flowers are greenish-yellow in colour, star-shaped, and grow in spikes at the ends of young shoots in spring (August to September). The fruits are nut-like and about 3 mm in diameter (December to January).
 This tree is usually found growing in dense thickets at altitudes above 1000 metres. It can be found growing in open grassland, along river banks and on wooded, rocky ridges. It is usually found growing in damp conditions, on deep, sandy or clayey and often rocky soil. Leucosidea sericea occurs in the Eastern Cape, Lesotho, western KwaZulu-Natal, the eastern Free State, North West, Gauteng, Mpumalanga, and Limpopo provinces, Swaziland and Zimbabwe.
 The flowers and young shoots of this plant are browsed by cattle and goats in spring. It forms dense thickets on overgrazed, eroded or otherwise disturbed areas and can, therefore, become a problem plant on farm lands. The ouhout produces nectar which is probably utilised by bees and other insects.


The wood makes good, durable fence posts in permanently wet soil even though it is soft. Apparently in mountainous areas where the ouhout occurs near streams it is an indication that they are suitable for being stocked with trout. Zulu people use a paste made from the crushed leaves of Leucosidea sericea for treating ophthalmia (an eye ailment). The tree is used by the local people as a charm to protect the inhabitants of homesteads. The wood of this tree burns slowly and produces a lot of smoke like old and decaying wood. This together with the appearance of the flaky bark has given rise to the tree's common name of "oldwood".
Info: http://www.plantzafrica.com/

Thursday, April 11, 2013

Butterfly Pea (Clitoria ternatea)

Family Fabaceae
 In traditional Ayurvedic medicine, it has been used for centuries as a memory enhancer, nootropic, antistress, anxiolytic, antidepressant, anticonvulsant, tranquilizing and sedative agent. In Southeast Asia the flowers are used to colour food. In Malay cooking, an aqueous extract is used to colour glutinous rice for kuih ketan (also known as pulut tai tai in Peranakan/Nyonya cooking) and in nonya chang. In Thailand, a syrupy blue drink is made called nam dok anchan (น้ำดอกอัญชัน), it is commonly consumed with a drop of lime juice to increase acidity and turn the juice in to pink-purple. In Burma the flowers are used as food, often they are dipped in batter and fried.
 In animal tests the methanolic extract of Clitoria ternatea roots demonstrated nootropic, anxiolytic, antidepressant, anticonvulsant and antistress activity. The active constituents include tannins, resins, starch, taraxerol and taraxerone.
 Recently, several biologically active peptides called cliotides have been isolated from the heat-stable fraction of Clitoria ternatea extract. Cliotides belong to the cyclotides family and activities studies show that cliotides display potent antimicrobial activity against E. coli, K. pneumonia, P. aeruginosa and cytotoxicity against Hela cells. These peptides have potential to be lead compound for the development of novel antimicrobial and anti-cancer agents
Info: http://en.wikipedia.org/wiki/Clitoria_ternatea