Ageratina glabrata (Kunth) R.M.King & H.Rob.

Taxonomic Identity

Ageratina glabrata (Kunth) R.M.King & H.Rob. is a woody shrub that grows up to 2.4 meters (around 8 feet) tall. It has several key distinguishing characteristics.

Leaf Arrangement and Shape

Its leaves grow in opposite pairs, are longer than they are wide, have pointed tips, and have margins ranging from toothed to nearly smooth.

Leaf Surface and Texture

Leaf blades are hairless, somewhat resiny and shiny, with glands dotted across their lower surface; leaf texture varies from thin to somewhat leathery.

Inflorescence Structure

The plant's flowers grow in heads that contain only 15-18 disk florets with cylindrical corollas, and these heads are arranged in cyme-type inflorescences.

Corolla Characteristics

Corollas are white, sometimes with pinkish lobes, and reach up to around 7 mm (about 3⁄16 inch) long.

Fruit Description

The fruit is a one-seeded, non-splitting cypsela with a pappus that is almost as long as the corolla.

Endemic Range

Ageratina glabrata is endemic to Mexico, ranging from the northern states of Sinaloa, Durango, and Tamaulipas south to Oaxaca and Puebla.

Habitat and Elevation

It grows in fir forests, oak and pine forests, and mesophytic forests at elevations between 2600 and 3500 meters (around 8550 to 11,500 feet), and is abundant in the understory of managed temperate forests in central Mexico.

Flowering Pattern

This species has a continuous flowering pattern year-round.

Ecological Adaptation

Compared to closely related species, Ageratina glabrata's greater height and cover suggest it is adapted to open environments.

Traditional Medicinal Use

In Mexican traditional medicine, Ageratina glabrata is recognized to have analgesic activity; one of its common names is hierba del golpe, which loosely translates to 'plant for hits'.

Analgesic Effect Tests

Preliminary controlled tests using the hot plate and tail flick methods in rats found that plant extract provided analgesic effects that lasted 5 hours after administration.

Phytochemical Properties

An additional study that documented the plant's traditional use for stomach pain and postpartum baths confirmed Ageratina glabrata contains antioxidants that may account for its traditional usefulness.