Ageratum houstonianum (a-ge-RAY-tum hew-stone-ee-AH-num) is most commonly known as floss flower or pussy-foot but is sometimes called “artist paintbrush” because of the brushlike appearance of its small blossoms, which grow in clusters. The leaves are “felted,” or hairy, and they are somewhat heart-shaped, with shallowly toothed or serrated edges.
The name Ageratum comes from the Greek roots “a” (without) and “geras” (age), referring to the flowers’ retaining their color for a long time. The species houstonianum was named after William Houston (1695-1733), an American physician who collected plants in the Antilles and Mexico.
Ageratum is a member of the Compositae or Asteraceae family, which has the largest number of commercially grown plants in the world. Relatives include Dahlias, Asters, cornflowers, daisies, sunflowers and chrysanthemums as well as many vegetable crops like lettuce. Ageratums are indigenous to the Central American countries of Mexico, Belize, Guatemala and Honduras as well as the West Indies and Southern Florida.
Ageratums contribute blue-violet, red-violet, violet-blue, lilac, pink and white to the floral artist’s palette. They are readily available from June through October from both domestic and Dutch growers although some varieties are available year-round from Holland.
Ageratums are utilized in traditional medicine by various cultures worldwide. Extracts are used to treat pneumonia and to cure wounds and burns. Ageratums also are used to kill bacteria, to prevent dysentery and to prevent the formation of gall or kidney stones.