plant poisons

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plant poisons

Post by mohweh on Thu Mar 27, 2008 4:35 pm

Despite,the head of this part of forums is clinical toxicology,the following topic will have the plants of toxicological value from the botanical and descriptive point of view.

atropa belladona
The root is thick, fleshy and whitish, about 6 inches long, or more, and branching. It is perennial. The purplishcoloured stem is annual and herbaceous. It is stout, 2 to 4 feet high, undivided at the base, but dividing a little above the ground into three - more rarely two or four branches, each of which again branches freely.
The leaves are dull, darkish green in colour and of unequal size, 3 to 10 inches long, the lower leaves solitary, the upper ones in pairs alternately from opposite sides of the stem, one leaf of each pair much larger than the other, oval in shape, acute at the apex, entire and attenuated into short petioles.

The whole plant is glabrous, or nearly so, though soft, downy hairs may occur on the young stems and the leaves when quite young. The veins of the leaves are prominent on the under surface, especially the midrib, which is depressed on the upper surface of the leaf.
The fresh plant, when crushed, exhales a disagreeable odour, almost disappearing on drying, and the leaves have a bitter taste, when both fresh and dry.
The flowers, which appear in June and July, singly, in the axils of the leaves, and continue blooming until early September, are of a dark and dingy purplish colour, tinged with green, large (about an inch long), pendent, bell-shaped, furrowed, the corolla with five large teeth or lobes, slightly reflexed. The five-cleft calyx spreads round the base of the smooth berry, which ripens in September, when it acquires a shining black colour and is in size like a small cherry. It contains several seeds. The berries are full of a dark, inky juice, and are intensely sweet, and their attraction to children on that account, has from their poisonous properties, been attended with fatal results.





cannabis
The plant is an annual, the erect stems growing from 3 to 10 feet or more high, very slightly branched, having greyish-green hairs. The leaves are palmate, with five to seven leaflets (three on the upper leaves), numerous, on long thin petioles with acute stipules at the base, linear-lanceolate, tapering at both ends, the margins sharply serrate, smooth and dark green on the upper surface, lighter and downy on the under one. The small flowers are unisexual, the male having five almost separate, downy, pale yellowish segments, and the female a single, hairy, glandular, five-veined leaf enclosing the ovary in a sheath. The ovary is smooth, one-celled, with one hanging ovule and two long, hairy thread-like stigmas extending beyond the flower for more than its own length. The fruit is small, smooth, light brownish-grey in colour, and completely filled by the seed.



erythroxylon coca
Small shrubby tree 12 to 18 feet high in the wild state and kept down to about 6 feet when cultivated. Grown from seeds and requires moisture and an equable temperature. Starts yielding in eighteen months and often productive over fifty years. The leaves are gathered three times a year, the first crop in spring, second in June, and third in October; must always be collected in dry weather. There are two varieties in commerce, the Huanuco Coca, or Erythroxylon Coca, which comes from Bolivia and has leaves of a brownish-green colour, oval, entire and glabrous, with a rather bitter taste, and Peruvian Coca, the leaves of which are much smaller and a pale-green colour. Coca leaves deteriorate very quickly in a damp atmosphere, and for this reason the alkaloid is extracted from the leaves in South America before exportation.



datura
The Thornapple is a large and coarse herb, though an annual, branching somewhat freely, giving a bushy look to the plant. It attains a height of about 3 feet, its spreading branches covering an area almost as broad. On rich soil it may attain a height of even 6 feet.

The root is very long - thick and whitish, giving off many fibres. The stem is stout, erect and leafy, smooth, a pale yellowishgreen in colour, branching repeatedly in a forked manner, and producing in the forks of the branches a leaf and a single, erect flower. The leaves are large and angular, 4 to 6 inches long, uneven at the base, with a wavy and coarsely-toothed margin, and have the strong, branching veins very plainly developed. The upper surface is dark and greyish-green, generally smooth, the under surface paler, and when dry, minutely wrinkled.

The plant flowers nearly all the summer. The flowers are large and handsome, about 3 inches in length, growing singly on short stems springing from the axils of the leaves or at the forking of the branches. The calyx is long, tubular and somewhat swollen below, and very sharply five-angled, surmounted by five sharp teeth. The corolla, folded and only half-opened, is funnel-shaped, of a pure white, with six prominent ribs, which are extended into the same number of sharppointed segments. The flowers open in the evening for the attraction of night-flying moths, and emit a powerful fragrance.
The flowers are succeeded by large, eggshaped seed capsules of a green colour, about the size of a large walnut and covered with numerous sharp spines, hence the name of the plant. When ripe, this seed-vessel opens at the top, throwing back four valve-like forms, leaving a long, central structure upon which are numerous rough, dark-brown seeds. The appearance of the plant when in flower and fruit is so peculiar that it cannot be mistaken for any other native herb.

The plant is smooth, except for a slight downiness on the younger parts, which are covered with short, curved hairs, which fall off as growth proceeds. It exhales a rank, very heavy and somewhat nauseating narcotic odour. This foetid odour arises from the leaves, especially when they are bruised, but the flowers are sweet-scented, though producing stupor if their exhalations are breathed for any length of time.


digitalis purpurea
The normal life of a Foxglove plant is two seasons, but sometimes the roots, which are formed of numerous, long, thick fibres, persist and throw up flowers for several seasons.
In the first year a rosette of leaves, but no stem, is sent up. In the second year, one or more flowering stems are thrown up, which are from 3 to 4 feet high, though even sometimes more, and bear long spikes of drooping flowers, which bloom in the early summer, though the time of flowering differs much, according to the locality. As a rule the flowers are in perfection in July. As the blossoms on the main stem gradually fall away, smaller lateral shoots are often thrown out from its lower parts, which remain in flower after the principal stem has shed its blossoms. These are also promptly developed if by mischance the central stem sustains any serious injury.
The radical leaves are often a foot or more long, contracted at the base into a long, winged footstalk, the wings formed by the lower veins running down into it some distance. They have slightly indented margins and sloping lateral veins, which are a very prominent feature. The flowering stems give off a few leaves, that gradually diminish in size from below upwards. All the leaves are covered with small, simple, unbranched hairs.
The flowers are bell-shaped and tubular, 1 1/2 to 2 1/2 inches long, flattened above, inflated beneath, crimson outside above and paler beneath, the lower lip furnished with long hairs inside and marked with numerous dark crimson spots, each surrounded with a white border. The shade of the flowers varies much, especially under cultivation, sometimes the corollas being found perfectly white.
In cultivated plants there frequently occurs a malformation, whereby one or two of the uppermost flowers become united, and form an erect, regular, cup-shaped flower, through the centre of which the upper extremity of the stem is more or less prolonged.



Last edited by mohweh on Fri Mar 28, 2008 2:48 am; edited 3 times in total

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Re: plant poisons

Post by mohweh on Thu Mar 27, 2008 4:38 pm

hyoscyamus
H. niger is susceptible of considerable diversity of character, causing varieties which have by some been considered as distinct species. Thus the plant is sometimes annual, the stem almost unbranched, smaller and less downy than in the biennial form, the leaves shorter and less hairy and the flowers often yellow, without any purple markings. The annual plant also flowers in July or August, the biennial in May and June.
The whole plant has a powerful, oppressive, nauseous odour.




khat
Believed to have originated in Ethiopia, khat is a slow-growing shrub or small tree that grows to between 1.5 metres and 20 metres tall, depending on region and rainfall, with evergreen leaves 510 cm long and 14 cm broad. The flowers are produced on short axillary cymes 48 cm long, each flower small, with five white petals. The fruit is an oblong three-valved capsule containing 13 seeds.




nutmeg
The tree is about 25 feet high, has a greyish-brown smooth bark, abounding in a yellow juice. The branches spread in whorls - alternate leaves, on petioles about 1 inch long, elliptical, glabrous, obtuse at base - acuminate, aromatic, dark green and glossy above, paler underside and 4 to 6 inches long. Flowers dioecious, small in axillary racemes. Peduncles and pedicles glabrous. Male flowers three to five more on a peduncle. Calyx urceolate, thick and fleshy, covered with an indistinct reddish pubescence dingy pale yellow, cut into three erect teeth. Female flowers differ little from the male, except pedicel is often solitary. Fruit is a pendulous, globose drupe, consisting of a succulent pericarp - the mace arillus covering the hard endocarp, and a wrinkled kernel with ruminated endosperm. When the arillus is fresh it is a brilliant scarlet, when dry more horny, brittle, and a yellowish-brown colour. The seed or nutmeg is firm, fleshy, whitish, transversed by red-brown veins, abounding in oil. The tree does not bloom till it is nine years old, when it fruits and continues to do so for seventy-five years without attention.




papaver somniferum
The plant is an erect, herbaceous annual, varying much in the colourof its flowers, as well as in the shape of the fruit and colour of the seeds. All parts of the plant, but particularly the walls of the capsules, or seed-vessels, contain a system of laticiferous vessels, filled with a white latex.
The flowers vary in colour from pure white to reddish purple. In the wild plant, they are pale lilac with a purple spot at the base of each petal. In England, mostly in Lincolnshire, a variety with pale flowers and whitish seeds is cultivated medicinally for the sake of the capsules. Belgium has usually supplied a proportion of the Poppy Heads used in this country, though those used for fomentations are mostly of home growth.

The capsules vary much in shape and size. They are usually hemispherical, but depressed at the top, where the many-rayed stigma occupies the centre; they have a swollen ring below where the capsule joins the stalk. Some varieties are ovoid, others again depressed both at summit and base.

The small kidney-shaped seeds, minute and very numerous, are attached to lateral projections from the inner walls of the capsule and vary in colour from whitish to slate. The heads are of a pale glaucous green when young. As they mature and ripen they change to a yellowish brown, and are then cut from the stem if the dried poppy heads are required.



strychnos nux-vomica
A medium-sized tree with a short, crooked, thick trunk, the wood is white hard, close grained, durable and the root very bitter. Branches irregular, covered with a smooth ash-coloured bark; young shoots deep green, shiny; leaves opposite, short stalked, oval, shiny, smooth on both sides, about 4 inches long and 3 broad; flowers small, greeny-white, funnel shape, in small terminal cymes, blooming in the cold season and having a disagreeable smell. Fruit about the size of a large apple with a smooth hard rind or shell which when ripe is a lovely orange colour, filled with a soft white jelly-like pulp containing five seeds covered with a soft woolly-like substance, white and horny internally.


The seeds have the shape of flattened disks densely covered with closely appressed satiny hairs, radiating from the centre of the flattened sides and giving to the seeds a characteristic sheen; they are very hard, with a dark grey horny endosperm in which the small embryo is embedded; no odour but a very bitter taste.




nicotiana tabacum
The genus derives its name from Joan Nicot, a Portuguese who introduced the Tobacco plant into France. The specific name being derived from the Haitian word for the pipe in which the herb is smoked. Tobacco is an annual, with a long fibrous root, stem erect, round, hairy, and viscid; it branches near the top and is from 3 to 6 feet high.
Leaves large, numerous, alternate, sessile, somewhat decurrent, ovate, lanceolate, pointed, entire, slightly viscid and hairy, pale-green colour, brittle, narcotic odour, with a nauseous, bitter acrid taste. Nicotine is a volatile oil, inflammable, powerfully alkaline, with an acrid smell and a burning taste. By distillation with water it yields a concrete volatile oil termed nicotianin or Tobacco camphor, which is tasteless, crystalline, and smells of Tobacco; other constituents are albumen, resin, gum, and inorganic matters.


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Re: plant poisons

Post by Dr Sarhan on Sat Mar 29, 2008 9:27 am

Wooooooooooooow .. Great ..
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Re: plant poisons

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