St.
john's wortErect, diffusely branched, perennial herb; smaller stems wing-angled. Leaves with tiny, nearly clear spots, opposite, elliptic to oblong, usually five-veined, entire, 1 to 2.5 cm long, 2.5 to 11 mm, wide, base clasping, sessile. Flowers deep yellow; petals 7 to 10 min long, with tiny, black spots; borne in decompound, flat-topped clusters. Fruit, a many seeded capsule, ovoid, 3.5 to 5.5 mm long, 2.5 to 4 mm broad. Seeds brown, 1 to 1.2 min long. Found throughout the south; dry fields, waste places, roadsides, mostly in piedmont or mountains.
TOXICITY
A red fluorescent pigment, hypericin, is the toxic agent. It is a primary photosensitizing compound although the liver is not affected. Light areas of the skin surface become hypersensitive to sunlight. Cattle, sheep and horses are affected; also goats, but to a lesser degree. Animals are poisoned by eating the fresh plant or dried hay. The toxic principle is not destroyed by drying or excessive heat. Younger plants are more palatable than the older ones.
SYMPTOMS
In cattle, consumption of the toxic plant amounting to one percent of the body weight is toxic. Photosensitization is noticed within two days to three weeks after ingestion. The white skin peels off and may hang from the body before failing away. Affected animals exhibit itching and try to scratch themselves on objects. Blindness often results from inflammation and secondary infection of the cornea. Animals occasionally have convulsions in the acute form of poisoning. More commonly, however, the photosensitization results in secondary infection of the affected areas. Animals may actually die of starvation.
TREATMENT
Remove animals from contaminated pastures to barns, woods, pasture or areas where animals have access to shade. Affected skin areas should be treated with antibacterial preparations as well as antibiotic injections to prevent infection.
SweetshrubShrub with opposite branches, 1 to 3 in tall. Leaves opposite, deciduous, entire, lanceolate to ovate, 5 to 18 cm long, 2 to 8 cm wide, entire. Flowers axillary with many linear or lanceolate, maroon petals and sepals, very fragrant. Fruit dry, tough, obovate, fibrous, 8 cm or more long and 5 cm or more in diameter; resembling an insect gall. Found in Alabama, Florida, Georgia, Mississippi, Tennessee, Virginia; mostly in rich, deciduous woods along stream banks and other moist places.
TOXICITY
An alkaloid is contained in the seed of the plant. It has been reported to be toxic to cattle. It is dangerous but not usually eaten.
SYMPTOMS
Strychnine-like action results in an increased excitability in which tetanic convulsions are exhibited.
TREATMENT
Due to its strychnine-like action, sedatives may be of value in controlling the convulsions.
