Poisonous Plants of the Southern United States

mexicanpoppy.jpg (55540 bytes)mexican poppy
Argemone mexicana (bluestem pricklepoppy,
Argemone intermedia, is shown)

Annual or biennial herb, 3 to 9 m tall, more or less spiny; plant sap bright yellow. Leaves alternate, glaucous, auriculate clasping, sessile, lanceolate to obovate, 7 to 20 cm long, 3 to 9 cm wide, coarsely pinnately cleft or parted; margins spinose dentate. Flowers showy with very short stems; corolla bright or rarely pale yellow; petals 3 to 5 cm wide. Found throughout most of the south; sandy roadsides, waste places and fields.

TOXICITY

The alkaloids berberine and protopine are contained in the entire plant. In addition, the seeds contain sanquinarine and dihydrosanquinarine. If consumed in sufficient quantities, livestock, humans and chickens can be poisoned. One ounce of seed causes symptoms in poultry and two ounces usually produce death.

SYMPTOMS

In humans and chickens, widespread edema (dropsy) is the main finding. Chickens exhibit a swelling of the wattles and darkening of the tips of the comb and also a decrease in egg production, weakness, hemorrhagic enteritis and death.

TREATMENT

Non-specific. Diuretics may be of value in livestock.

 

hairyvetch.jpg (36801 bytes)hairy vetch
Vicia villosa

Annual, biennial or rarely perennial, trailing or climbing herb, .5 to 1 in tall, with densely hairy stems (a cultivated variety is not hairy). Leaves alternate, pinnately compound, terminal leaflet modified into a branched tendril; leaflets 10 to 29, narrowly oblong to linear, I to 3 cm long. Flowers violet or rarely white, 1.2 to 2 cm long; 10 to 40 flowers borne together in racemose axillary clusters. Fruit, a flattened pod, 2 to 3 cm long, 7 to 10 min broad. Found throughout the southern states east of the Mississippi River; fields, roadsides and waste places.

TOXICITY

A cyanogenetic glycoside is present in vetch seed. In Alabama, cattle exhibited signs of cyanide poisoning after eating from a sack of vetch seed that was left in a barnyard.

SYMPTOMS

Symptoms include bellowing, sexual excitement, a wild appearance, crawling on the ground and death. Some species of vetch have been known to cause liver damage and photosensitization.

TREATMENT

Treatment of cyanide poisoning should include sodium thiosulfate and sodium nitrite. Cattle exhibiting photosensitization should be kept in a shady area and given antibiotics to prevent secondary infection.

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