Datura stramonium: Datura stramonium

Family: Solanaceae (nightshade family)

Common names:  thorn apple, common thorn apple, datura, devil’s trumpet, jimsonweed, moonflower

French: Stramoine commune; Kinyarwanda: Rwiziringa; Amharic: Atefaris, Astenagir, Stanagirt, Manji; Oromo: Asangira; Tigrgna: Mezerbae, Trifara; Kiswahili: Muana.

Annual broadleaved bushy herb (0.5–2 m tall); stems green, purple or brown, hairy to hairless; single stem divides into two branches, each of which again divides into two branches as they grow, and so on; plants with strong tap root.

Leaves: Dark green (sometimes purple), hairless, egg-shaped to broadly triangular (5–25 cm long and 4–25 cm wide), with prominent veins, margins coarsely and irregularly toothed or lobed; alternate on stems on long petioles (up to 10 cm); bad-smelling when crushed.

Flowers: White, mauve or purplish, funnel-shaped and large (up to 10 cm long) at each fork of the stem.

Fruits/Seeds: Capsules, green turning brown as maturing, egg-shaped (3–7 cm long, 2–3.5 cm wide), covered with slender spines (up to 10 mm long) and held erect on the plant. Seeds numerous, dark brown to black, flat and kidney-shaped.

Origin: Unclear, but probably tropical America.

Introduction: As ornament and accidentally as contaminant of seed.

Habitat: Warm-temperate and subtropical regions; mainly in open situations on fertile soil.

Spread: Seeds fall 1-3m from the plant when fruits open; disturbance by machines, animals or humans enhances spread; can be moved with machinery and by birds.

Invades: Crops, pasture, fallow land, disturbed land, wasteland, drainage ditches, woodland edges/gaps, gullies and dry riverbeds.

Impacts: The weed competes aggressively with native plants and crops, forming dense monospecific stands. Infestations may result in significant yield loss in cotton (>50%). Yields of soya bean plants growing at a distance of 1.2 m from a D. stramonium plant are significantly reduced, demonstrating the negative impacts of this weed on the growth of neighbouring plants. In Spain, competition in irrigated maize has reduced yields by 56%. At densities of 3–11 plants per m², yields of tomatoes may be reduced by 26–71%. The weed is an alternative host for several pests and pathogens of solanaceous crops. Toxic to people, horses, cattle, sheep, pigs and chickens, the species has gained notoriety as a plant that is used by people to commit suicide.