Family: Solanaceae
Datura
Citation:
L., Sp. Pl. 179 (1753).
Derivation: Hindi dhatura, apparently the name for D. metel.
Synonymy: Not Applicable Common name: Thornapples.
Description:
Stout malodorous annual or perennial herbs, essentially glabrous or pubescent with simple glandular or non-glandular hairs; leaves alternate, simple, entire or lobed, petiolate.
Flowers solitary in branch forks, bisexual; calyx tubular, with usually 5 (rarely 3, 4 or up to 9) teeth, at length circumscissile near the base; corolla regular, funnel- or trumpet-shaped, rarely multiple, with a plain or marked throat and usually 5 (rarely up to 9) broad cuspidate lobes, the tissue between the lobes sometimes excessively developed and the limb appearing 10- or 12-lobed; lobes plicate and twisted in bud; stamens 5 (or up to 8), equal, included in the corolla, the filaments adnate to the corolla for one-third to one-half of their length from the base; anthers loosely cohering, 2-celled, dehiscing longitudinally; ovary 2-celled, often falsely 4-celled in the lower half, beset with soft spinules.
Fruit a spiny or tuberculate capsule dehiscing septifragally in 4 valves or breaking irregularly from the apex, subtended by a collar formed by the enlarged reflexed persistent calyx base; pedicel erect or deflexed; seeds ear-shaped, thick or flat; testa minutely pitted.
Distribution:
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About 10 species, in south-western United States, Central America and Asia, with 1 species generally considered native to Australia, where a further 5 species are naturalised and declared noxious weeds in most States.
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Biology:
No text
Uses:
Several species have long been used as drug plants; most are poisonous to stock. (Haegi (1976)Aust. J. Bot. 24:415-435).
Key to Species:
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1. Leaves with at least some lobes toothed or sinuate; capsule erect; seeds black or grey |
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2. Flowers 6-10 cm long; capsule with more than 100 slender spines of varying lengths, evenly distributed |
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D. stramonium 5. |
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2. Flowers 4.5-6 cm long; capsule with 40-60 stout spines, those towards the base markedly shorter |
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D. ferox 1. |
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1. Leaves entire or if lobed then lobes entire; capsule deflexed; seeds brown or yellow (sometimes grey) |
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3. Plants glabrous or sparsely pubescent with non-glandular hairs |
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4. Flowers 4.5-7 cm long; capsule with sharp spines |
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D. leichhardtii 3. |
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4. Flowers 12-20 cm long; capsule with blunt tubercles |
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D. metel 4. |
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3. Plants densely pubescent with at least some glandular hairs present |
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5. Hairs on branches and leaves all erect and glandular; stigma borne well below the anthers |
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D. inoxia 2. |
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5. Hairs on branches and leaves mostly retrorse and non-glandular; stigma usually exserted well above the anthers |
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D. wrightii 6. |
Author:
Prepared by L. Haegi
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