Ageratina altissima, White snakeroot is a poisonous, perennial, shrubby plant that belongs to the Compositae (Asteraceae) family. It is known by the following names: richweed, white sanicle, and tall boneset.
Ageratina altissima var. angustata and Ageratina altissima var. roanensis. They differ in the length and shape of the flower tips.
Structure of Ageratina altissima
The ageratina altisima has an erect or upward-creeping growth. It reaches a height of up to 1.5-2 m, forming a single or several tufts of plant mass. Its root system consists of a widely spreading rhizome, with shallowly spaced fibrous roots. This plant can be propagated vegetatively by its roots or sown in new locations by its seeds. The stems are coloured from light green to red-brown, smooth, round in cross-section and without hairs.
The leaves are oppositely arranged on the branches, becoming smaller towards the tips of the plant. The low-lying leaves are heart-shaped to heart-ovate, while the higher-growing leaves are broadly lanceolate or lanceolate only. The entire foliage is almost hairless, coloured medium to dark green on the upper surface and light green on the lower surface. There are three prominent leaf veins on the upper surface, and the lower surface is all with a distinct network of them. The leaf margin is toothed.
It develops small white flowers gathered in a co-flowered held from 10 to 30 in number. The flower stalks are light green and hairless. The size of each floret is about 3-5 mm, the size at full flower opening. It consists of a tubular part and five petals. Each flower head has only one series of linear floral bracts, which are light green and do not overlap. The flowering period begins in mid to late summer and lasts about 2 months or until late autumn. This is one of the last wildflowers to bloom in the fall. The flowers are fragrant.
In place of each flower, dry fruit is formed with a small tuft of fluffy, white hairs. Fruits are about 2-3 mm long, narrow and oblong in shape, speckled, coloured black and easily spread by the wind.
Distribution of Ageratina altisima
It is native to the eastern part of North America. This species is adaptable to a variety of growing conditions. It can be found in shady and desolate places, as a weed or in hedgerows, in sunny and moist areas. It grows generally indigenously and under a variety of climatic conditions. Its most common habitat is woodland, developing as dense thickets.
Usable part of the ageratina altisima
The root of the plant is used.
Chemical composition of ageratina altisima
White snake root contains tremetol, alcohol, glycosides.
Medicinal properties and uses of ageratina altisima
Ageratina altisima is a diaphoretic, diuretic, antipyretic, stimulant, tonic, and toothache.
Ageratina altisima root tea has been used to treat malaria, diarrhoea, kidney stones, other urinary tract diseases and fever. A paw of it can be applied to the site of a snake bite. Baths of the plant have been used to promote sweating. A decoction or infusion of the root has been included in the treatment of uterine ailments. The root itself has been chewed for toothache.
White snakeroot contains the toxin tremetol. When the plant is consumed by cattle, the meat and milk derived from them become contaminated with the toxin. Thus consumed, the poison is transmitted to humans. If taken in large quantities, it can cause poisoning of the individual. The poisoning is called “milk sickness”.
The plants are also poisonous to horses, goats and sheep. Signs of poisoning in these animals include depression and lethargy, placing hind legs close together (horses, goats, cattle), or holding away from each other (sheep), nasal discharge, increased salivation, arched body posture, and rapid or laboured breathing.
Ageratina altisima easily attracts bees and butterflies with its fragrant and beautiful flowers. It is successfully incorporated into floral decorations and is extremely convenient for these purposes because of its late flowering period at the end of the warm seasons.