Foliage Friday: Ageratum (Floss Flower)

This fluffy flower caught my eye the other day, and I didn’t know what it was, so it’s the next Foliage Friday flower! I saw it planted in the flower beds in front of the main entrance of the hospital amongst other flowers, including roses, dahlias, and geraniums.

A quick google search revealed that these are a species of Ageratum. I’m not sure exactly which member of the Ageratum genus this is, but if I had to guess I would say Ageratum houstonianum, which also goes by the common names “floss flower” or “blue mink.”

Ageratum is a member of the Asteraceae family, which includes asters (obviously), dandelions, chrysanthemums, dahlias, cone flowers, sunflowers, black-eyed susans, cosmos, zinnias, and more. Asteraceae used to go by the name Compositae, and the defining feature of this family of that the flowers are actually composites of many smaller flowers but look like one big flower. I’m not sure why the name changed. Asteraceae comes from the root aster-,which means star. Here is a picture that illustrates what a composite flower is, and this website does a good job of describing the features:

Image from

The bright blue pom-pom like flowers of this Ageratum are quite eye-catching. The flowers supposedly last from early summer through October. It is native to Central and South America, and is an annual unless you live in zones 10 or 11. Be aware: some sources say that all parts of this plant are hepatotoxic, so look, but don’t eat!