Poisonous Plants of the Southern United States

spottedwaterhemlock.jpg (40792 bytes)spotted water hemlock
Cicuta maculata

Glabrous, branching, perennial herb, .6 to 2 m tall with purple striped or mottled, glabrous, hollow stems arising from fibrous or fleshy roots (like a dahlia). Lengthwise splitting of the juncture of the stem and roots shows the center is hollow with broad partitions of pithy tissue. Leaves alternate, pinnately, bipinnately or pinnate-ternately divided, uppermost leaves not dissected. Flowers white; borne in compound, flat-topped umbels at the ends of stems and branches. Fruits ovoid, prominently ribbed, two-parted, 2 to 4 mm long. Found throughout the south but , seldom common; swamps, stream banks, marshes, wet pastures, roadside ditches.

TOXICITY

A very poisonous alkaloid and resinoid are found in all parts of the spotted water hemlock, primarily in the roots. The pithy area between the nodes contains a greenish-yellow oil which contains the toxins.

Livestock and humans are especially susceptible to this poison. The plant grows in soil which is wet and damp, which enables the animal to easily pull up the plant. Most cases occur in the springtime.

SYMPTOMS

Animals exhibit nervous symptoms because of the toxin, which is a convulsant. Trembling motions are followed by convulsions. In addition, frothing at the mouth, chewing movements of the mouth and vomiting may be seen. The eyes are widely dilated and the temperature is elevated. Death occurs from respiratory failure.

TREATMENT

Gastrointestinal evacuation is suggested.

poison hemlock Conium maculatum

Glabrous, branching, biennial herb, to 2 m tall with hollow spotted stems arising from a thick taproot. Very similar to the much more poisonous Cicuta maculata and often confused with it. However, it usually has only one fleshy taproot; there are pithy partitions in a hollow area at the juncture of the root; stem and upper stem leaves are divided. Probably more common than Cicuta maculata but growing in the same kind of habitats.

TOXICITY

The poison hemlock contains coniine, an alkaloid, and other compounds that are capable of poisoning livestock, poultry and humans. The stems, leaves and mature fruits are toxic. The leaves are more dangerous in the springtime, and the fruit is the most dangerous in the fall.

SYMPTOMS

Gastrointestinal irritation, nervousness, trembling, staggering, coldness of the extremities, slow heartbeat and eventually coma and death.

TREATMENT

Respiratory stimulants may be used advantageously. Intestinal protectives are suggested.

 

castorbean.jpg (53653 bytes)castor bean
Ricinus communis

Large, robust, annual (in the south) or perennial (in tropics and subtropics), woody herb, to 3 m tall. Leaves alternate, up to 40 cm long, simple, palmately 7 to 9 lobed, serrate with gland-tipped teeth. Flowers green, inconspicuous; staminate flowers near the base and pistillate flowers mostly near the top of a small panicle. Fruit a three-lobed capsule with a soft, spiny exterior, 1.5 to 2 cm long; seeds three per capsule, resembling a female tick, shiny, grayish-brown mottled with reddish-brown, 10 mm long and 6 to 7 mm wide. Found throughout our area; cultivated and occasionally escaping and persisting in pinelands, waste places and roadsides.

TOXICITY

The poisonous principle is a phytotoxin called ricin. The plant is commonly planted in vegetable gardens in the southeast as an ornamental. Horses are most susceptible to poisoning but all livestock and humans can be affected. All parts of the plant are toxic, especially the seeds. Toxicity is seen most often in spring and summer.

SYMPTOMS

Animals are most often poisoned when feed grains have become contaminated with the castor bean seeds. Symptoms appear several hours to several days after consuming the toxin depending upon the amount consumed. Violent purgation in the form of straining and bloody diarrhea is the classical sign. Other signs are dullness, abdominal pain, weakness, trembling and incoordination.

TREATMENT

Intestinal protectives in large amounts, administered by stomach tube is necessary. If dehydrated, large amounts of intravenous fluids assist in recovery.

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