Plantinvasivekruger - Solanaceae - Datura stramonium L.

DATST

Solanaceae

Datura stramonium L.

Datura - from tatora (Arabic name).

D. stramonium is a great annual herb, erect, spreading, branching often dichotomous, with foul smell. It grows up to 1.50 m high. The leaves are simple, alternate, stalked, large, broadly ovate, margin with strong sharp teeth or lobed, dark-green, up from 15 to 20 cm long. Upleasent scented when crushed.The flowers are solitary in the axils of branches, large, white or purple, trumpet, more or less wrinkled and 6 to 9 cm long. The fruit is a capsule subglobose, erect, 4 to 6 cm long, covered with soft spines. It opens from the top into 4 valves. The seeds are black, very numerous.

Datura stramonium is similar to Datura ferox and Datura inoxia. D. inoxia is a large bushy sublignous herb; its morphology and behavior are similar to D. stramonium.
D. ferox can be distinguished from D. stramonium by its capsule which, has about 40-60 strong spines of variable length. D. ferox flower is shorter (4-6 cm long) compared to the flower of D. stramonium which is longer, up to 10 cm long.
Datura ferox and Datura stramonium produce erect capsules on straight stalks which contain black or grey seeds. Datura inoxia can be differentiated from these two species as its capsules are held on a curved stalk, and it produces brown or yellow seeds. D. inoxia is also distinguished by its stem, its branches and leaves which are entirely pubescent with simple glandular hairs, and by its leaves usually entire, rarely toothed. The branches are usually purple. The fruit is pubescent and covered with soft spines.

Cotyledons are linear lanceolate from 5 to 30 mm long and 4 to 5 mm wide. The lamina is green on the upper surface and tinged with purple on the lower surface.

First leaves are simple, alternate, borne on a stalk down from 12 to 18 mm. The lamina is oval lanceolate, 25 to 36 mm long and 8 to 12 mm wide, with sharp ridges, green on the upper surface and slightly tinged with purple on the lower surface.

Herbaceous plant, erect, forming a small bush of 0.5 to 2 m high.

Taproot with many secondary white roots.

Stem is cylindrical, solid, thick and sometimes woody at the base, quickly and regularly dichotomously divided. It is green or tinged with purple, glabrous or pubescent, simple hairs on young twigs and stems.

Leaves are simple, alternate, borne on a robust petiole, 3 to 11 cm long. The lamina is widely oval to lanceolate, entire or subentire in margin, sharply and irregularly toothed (3 to 5 lobed), with sinuses irregular and deep enough. The base is rounded, the top acute or acuminate. The venation is alternated. Both leaf surfaces are smooth and glabrous.

Inflorescences are solitary flowers, erect, terminal. They are supported by a short peduncle of 0.5 to 1 cm.

Large flowers on a solitary tube and erect. The calyx consists of 5 sepals united to form a narrow tube, down from 3 to 4.5 cm, 5 protruding longitudinal ribs and finished with subequal teeth acuminate 5 to 7 mm long. Corolla tube is narrow at the cup and then gradually tapered, white or purple, 6 to 10 cm long. The corolla is ribbed.There are five stamens, net white pubescent at the base, welded to the corolla with a 3 to 5 mm long anthers. The flowering period starts from January to June.

Fruits are subglobose capsules, erect, 3 to 6 cm long and 2 to 4 cm wide. It is thorny, covered with spines conical erect, divided into four zones separated by the suture lines of dehiscence. The fruit is dehiscent at the top, opening into 4 valves. The base of the calyx is persistent and form at the basis of fruit a green collar folded down, about 1 cm long. A capsule containing numerous seeds. The fruiting period starts from January to June.

Seeds are elliptical, flattened and wrinkled, 3 to 4 mm long, black.

D. stramonium is an annual plant that is propagated by seeds. The flowering period and fruit starts from January to June.

It is found in disturbed areas, village, roasides, riverine. Prefers humus rich soils.

Native to North America.

Distributed to the Eastern part of South Africa.

Distributed to the entire parts of KNP.

Cultivated for atropine. The blue-green dye from the leaves is used to decorate huts interiors. It is used traditionally to treat asthma, headaches and wounds. Used as an ornamental plant in the gardens.

Declared weed as category 1, Prohibited weed. It is an invasive plant with moderate impact on the ecosystem.

Post-emergence herbicides is applicable as a control method, mannual control of cut and digging is an effective control method for this weed.

Weed control is best achieved by post-emergence herbicides, advised to delay eradication in order to catch the late germinating individuals. Cut and digging control method.

-(AdventOI) Le Bourgeois, T., Carrara, A., Dodet, M., Dogley, W., Gaungoo, A., Grard, P., Ibrahim, Y., Jeuffrault, E., Lebreton, G., Poilecot, P., Prosperi, J., Randriamampianina, J.A., Andrianaivo A.P., and Théveny, F. (2008). Advent-OI: Principales adventices des îles du sud-ouest de l'Océan Indien. Cirad. Montpellier, France, Cirad.
-(A Field Guide to Wild Flowers Kwazulu-Natal and Eastern Region) Pooley, E. Published by The flora publications Trust c/o Natal Herbarium botanic Gardens Road, Durban 4001.
-(Problem plants of South Africa) Bromilow, C. (2001), Published by Briza Plublications CC
-(A revised list of alien plants for the Kruger National Park.Koedoe) Foxcroft, L.C., Henderson, L., Nichols, G.R., Martin, B.

http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=150830
http://idao.cirad.fr/SpecieSheet?sheet=adventoi/especes/d/datst/datst_fr.html