Botanical Gardens - Part 1

A stroll through the Botanical Gardens is always a pleasure.
The Crane Flower (Bird of Paradise) only starts to get its first flowers after it has been planted for 4-5 years.

They attract a lot of insects especially bees and ants to the sweet nectar.

All kinds of butterflies dance around in the warm sunlight.

The Wild Pear does not bear fruit but hundreds of beautiful blooms.

Many types of cycads are common here and protected by law.

Cycad - a protected species

South Africa is one of the world centres for cycad diversity. With 39 species of cycad, it ranks third, behind Australia and Mexico, for the countries with the highest numbers of cycads. Two species from southern Africa are extinct in the wild and all but one of the remaining South African cycads are believed to be threatened with extinction. Cycads are therefore one of the most threatened groups of plants in South Africa. They are also well known to gardeners and are an ideal flagship group to highlight the problems facing plants in South Africa. This shows the growth of the fruit/flower.

Porcupine Root (Talinum caffrum)

Family Portulacaceae

This plant is also known as: Flameflower

 Origin and geographic distribution
Talinum caffrum is found from southern Ethiopia south to Namibia, Botswana and South Africa.

Uses
The leaves of Talinum caffrum are collected from the wild and eaten raw as a salad or as a cooked vegetable. They contain much water and are also eaten raw against thirst. Occasionally, Talinum caffrum is cultivated as an ornamental, succulent potplant.

 Properties
The nutritional composition of Talinum caffrum leaves is not known, but it is probably comparable to that of Talinum triangulare (Jacq.) Willd.

 Botany
Perennial, rather succulent herb with a deeply buried tuber; stems annual, usually decumbent or prostrate, up to 40 cm long, much branched. Leaves alternate, simple; petiole 1–3 mm long; blade linear to narrowly elliptical, 2–8 cm × 3–13 mm, base cuneate, apex apiculate, margin often revolute. Flowers usually solitary in leaf axils, bisexual, opening in the afternoon; stalk consisting of 2 parts, lower part (peduncle) up to 2.5 cm long, tipped by a pair of bracts, upper part (pedicel) 1–2 cm long, stout, thickened upwards, recurving in fruit; sepals 2, lanceolate, 0.5–1.5 cm long; petals 5, spreading, obovate to elliptical, c. 1 cm long, yellow; stamens 25–60; ovary superior, style slender, 2–4 mm long, stigma 3-branched. Fruit a conical capsule 0.5–1 cm long, glossy yellow, 3-valved, the valves falling separately, many-seeded. Seeds lens-shaped, up to 2 mm in diameter, glossy black, with prominent concentric ridges.

Talinum comprises about 40 species, most of them found in Mexico and southern United States, and 7 species in tropical Africa. Talinum caffrum belongs to a complex of 4 closely related species characterized by a deeply buried tuber from which annual stems arise, alternate leaves, yellow flowers in axillary few-flowered cymes, opening in the afternoon, spreading petals and a hard and tough fruit with glossy black seeds. The other species of the complex are Talinum arnotii Hook.f., Talinum crispatulum Dinter and Talinum tenuissimum Dinter. All 4 species are similarly used and identification is particularly difficult when seed is lacking. The complex is centred in the Kalahari region in southern Africa, where the species are more distinct than further north in East Africa.

 Ecology
Talinum caffrum is found in dry open places in short grassland and among rocks, from sea-level up to 2000 m altitude. Because of its large tuber, it is drought resistant.

Genetic resources and breeding
Talinum caffrum is widespread and not in danger of genetic erosion. There are no known germplasm collections.

 Prospects
Talinum caffrum will remain a minor vegetable in drier areas, where it usually still produces leaves when other vegetables are scarce.

Info:

http://database.prota.org/dbtw-wpd/exec/dbtwpub.dll?ac=qbe_query&bu=http://database.prota.org/search.htm&tn=protab~1&qb0=and&qf0=Species+Code&qi0=Talinum+caffrum&rf=Webdisplay

ID: Andrew Hankey - http://www.ispot.org.za/node/158603?nav=latest_obs_thumbnail_grid

Whitetip Nightshade (Solanum chenopodioides)

Family Solanaceae

Part of the S. nigrum or "Black nightshade" group of species, usually referred to as cosmopolitan weeds and usually thought to have originated in the Americas. They are characterised by their lack of prickles and stellate hairs, their white flowers and their green or black fruits arranged in an umbelliform fashion.

The species can be difficult to distinguish. Other species to occur in Australia are S. americanum, S. douglasii, S. furcatum, S. nigrum, S. opacum, S. physalifolium, S. retroflexum, S. sarrachoides, S. scabrum and S. villosum.

Some members of the complex have long been important food and medical sources in parts of Africa, India, Indonesia and China. Leaves are used as herbs or as vegetables, fruits are edible and provide dye and the plants have been used for various medicinal treatments. However other parts of the complex are poisonous.

Because of this it is important to develop techniques for distinguishing between the species and the work to develop genetic markers is ongoing, particularly in Africa where these plants can provide a more easily obtained food resource than imported foods. Of the species which occur in Australia S. americanum, S. scabrum and S. villosum are all considered to be edible.

Toxicity varies widely depending on the variety and the location, and poisonous plant experts advise: "...unless you are certain that the berries are from an edible strain, leave them alone."

Info:

http://www.flora.sa.gov.au/efsa/lucid/Solanaceae/Solanum%20species/key/Australian%20Solanum%20species/Media/Html/Solanum_chenopodioides.htm

Identified by:

http://www.ispot.org.za/node/159033?nav=latest_obs_thumbnail_grid

Bell Spike-thorn (Gymnosporia tenuispina)

Family Celastraceae

 

This species is not endemic to South Africa and only found in the northern regions.

It prefers woodland, thickets and scrub on sandy or stony soil.

 Tests done by the CSIR in Pretoria list this plant as having high anti-cancer properties.

It grows to about 1.5m in height.

Identification by Cassine:  http://www.ispot.org.za/node/159034

Bushveld Crotalaria (Crotalaria laburnifolia)

Family Fabaceae

 As pretty as this plant is, there is no information about it except this extract:

“Although the toxicity of this species is not known, Crotalarias have been associated world-wide with poisoning in animals; the plants contain toxic alkaloids responsible mainly for severe liver and/or lung damage in livestock. Locally, members of the genus have been associated with jaagsiekte, a chronic respiratory disease in horses and mules and Stywesiekte in cattle, characterised by painful, warm hooves and abnormal hoof growth during chronic phase.”

Extract from: Wild flowers of South Africa (Braam van Wyk)

Fabaceae family:
 Members of the legume family have a symbiotic relationship with bacteria that live in their roots: these nitrifying bacteria are able to fix atmospheric nitrogen, making it available to the plant that is hosting them. When the plant dies, the nitrogen is released to the soil enriching it, and is then also available to other plants. This is what makes a lot of members of this family good pioneers-the first plants to inhabit a damaged or disturbed area, making it more habitable for other plants to also settle themselves. Other species of Crotalaria are used as cover crops and in re-vegetation projects for this reason, also to bind the sand and as windbreaks because they grow are fast growing.


They are pollinated mainly by carpenter bees. Blue butterfly larvae, of the family Lycaenidae, parasitize the pods. Chameleons are often found on the bushes waiting to predate the adult butterflies.

Simple-spined Num-num (Carissa edulis)

Family Apocynaceae

Description

Carissa edulis is a much branched spiny evergreen shrub or small tree, usually multistemmed, often scrambling up to 6 m tall and forming a dense canopy. All parts of the plant release white non-toxic milky latex.

This shrub has many traditional uses and forms a good hedge.

 Description

Carissa edulis is a much branched spiny evergreen shrub or small tree, usually multistemmed, often scrambling up to 6 m tall and forming a dense canopy. All parts of the plant release white non-toxic milky latex.

The plant is armed with rigid spines up to 70 mm long and nearly always simple, not forked as with other species.

 Leaves are simple and opposite, leathery, dark green above and paler below, with or without hair; and leaf base is shallowly lobed; margins are smooth; leaf stalk up to 5 mm long.


Flowers in terminal heads up to 40 mm in diameter, white tinged pink to purple and up to 20 mm long; corolla with lobes overlapping to the right, with a strong sweet jasmine-like scent. Flowering from September to December.

Fruits fleshy, ovoid, 6–11 mm in diameter, red to purplish black berries 2- to 4-seeded. Unripe fruits are green with red to purplish marks. Ripe fruits are dark red to purplish black.

 Habitat

It occurs in bushveld, often in riverine vegetation or on termite mounds,and common in deciduous to evergreen woodland; it is partial to granite soil.

Distribution

From Senegal and East Africa in the north to Mpumalanga and Limpopo in the south. Also in Asia to India and Thailand, and on some Indian Ocean islands.

 Uses and cultural aspects

Traditionally decoctions of roots are used as pain killer and to treat malaria. Taken warm and in small quantity it is also used for indigestion and for abnormal pains during pregnancy. The fruits help in the treatment of dysentery. The powdered root is used as a remedy for chest complaints. An infusion made from the roots is drunk to ease stomach ache, as a cough remedy or is dropped into the eye for cataract problems. Roots contain carissin that can be used to treat cancer. It has been successful in treating Herpes simplex virus.

Leaves are eaten by kudu, nyala, bushbuck, impala and grey duiker and the fruit eaten by kudu, grey duiker, baboons , monkeys and bush pigs. Fruits are edible, the milky red pulp having a pleasant sweet taste and being much sought after. The fruit can be fermented to make a refreshing pink wine or left longer to make vinegar. Birds favour the tree for nest building, and fruit eating birds (francolins, louries, hornbills, barbets and bulbuls) love the fruits.

If planted close together it can be grown as an effective hedge to keep intruders out and can take heavy pruning quite well. When planted as a hedge along a fence after a period of eight years the hedge will be so thick that no stock or game will be able to penetrate it. A delightful addition to any garden, it does not have an invasive root system and can be planted close to buildings. It makes a successful background plant with its scrambling habit and masses of fragrant whitish flowers. Boys eat the fruit when looking after livestock in the forest. It is also an ideal refuge for small animals and reptiles like snakes.

Info: http://www.plantzafrica.com/frames/plantsfram.htm

Plant identification: Braam van Wyk

Waaierbossie (Triumfetta sonderi)

Family Malvaceae

 There is no information available on this plant.

 It is fairy common in the Pretoria area and is a small, thick bush growing about 1m in height.

 The yellow flowers develope into the red seed pods and are somethime thought to be flowers.

Black Eyed Susan (Thunbergia alata)

Family Acanthaceae

In much of the warmer world, Thunbergia alata, or black-eyed susan, is well known as a fast-growing, long-flowering, friendly creeper. In South Africa it is a general favourite as it is not fussy about soil, needs only moderate water, doesn't go rampant, is mostly evergreen and covers ugly places beautifully. It has even been honoured in the standard set of South African postage stamps.

 Ecology
Black-eyed susan is probably pollinated by bees. An insect visiting the flower will touch the stigma first, with its back, and then the anthers, getting a load of pollen that is then carried to another stigma. The flowers reflect ultra violet light in a pattern that is visible to insects but not to humans. This helps insects find the centre of the flower. Seeds are perhaps ejected mechanically when the fruit splits open. A butterfly, Junonia ovithya, or the eyed pansy, and moths also visit these plants to lay eggs, for the larvae eat the leaves. Hence this creeper, being attractive to insects, helps bring birds into a garden. Birds also often nest in the thickly tangled stems.

 Uses and cultural aspects

Used mainly as an ornamental plant, Thunbergia alata makes a good screen when used to cover unsightly dead trees or walls. It needs some support, as it cannot cling. Use fences, trellises, arches, arbours and pillars or a lightly shading tree. (Pergolas would probably be too big.) Alternatively, plant this creeper in groups as a ground cover, or on a bank or terraces where it can trail downwards. Hanging baskets are also a possibility.

In East Africa, black-eyed susan is used as a vegetable or stock feed. Medicinally it is used for skin problems, cellulitis, back and joint pains, eye inflammation, piles and rectal cancer. Gall sickness and some ear problems in cattle are also treated with this plant. Some people can get contact dermatitis from it.

Info: http://www.plantzafrica.com/

Pink Sour Fig (Carpobrethus acinaciformis)

Family Mesembryanthemaceae

 Uses & cultural aspects


The leaf juice is astringent and mildly antiseptic. It is mixed with water and swallowed to treat diarrhoea, dysentery and stomach cramps, and is used as a gargle to relieve laryngitis, sore throat and mouth infections. Chewing a leaf tip and swallowing the juice is enough to ease a sore throat.

 Leaf juice or a crushed leaf is a famous soothing cure for blue-bottle stings-being a coastal plant it is luckily often on hand in times of such emergencies. The leaf juice is used as a soothing lotion for burns, bruises, scrapes, cuts, grazes and sunburn, ringworm, eczema, dermatitis, sunburn, herpes, nappy rash, thrush, cold sores, cracked lips, chafing, skin conditions and allergies. An old and apparently very powerful remedy for constipation is to eat fruits and then drink brackish water.

 Syrup made from the fruit is said to have laxative properties. A mixture of leaf juice, honey and olive oil in water is an old remedy for TB. The leaf juice also relieves the itch from mosquito, tick and spider bites both for people and their animal companions. The Khoikhoi took an infusion of the fruits during pregnancy to ensure a strong, healthy baby and an easy birth and smeared leaf sap over the head of a new-born child to make it nimble and strong. In the Eastern Cape it is also used to treat diabetes, and diptheria.

 Fruits are eaten by people and have been since ancient times. Archaeologists have found plants covering ancient middens along the coast and sometimes marking Khoikhoi burial sites (UCT Summer School lecture).


The sour fig is frequently cultivated as a sand binder, groundcover, dune and embankment stabilizer, and fire-resistant barrier and also a superb water-wise plant.

Info: http://www.plantzafrica.com/