Flossflower, Bluemink, Ageratum houstonianum, Kentlands Photowalk
These small flowers often provide color in front of white picket fences in Kentlands. Ageratum houstonianum, commonly known as flossflower, bluemink, blueweed, pussy foot or Mexican paintbrush, is a cool-season annual plant often grown as bedding in gardens.
The ordinary Ageratum is a perennial, herbaceous plant or a dwarf, or shrub. The plant grows to 0.3–1 m high, with ovate to triangular leaves 2–7 cm long, and blue flowerheads (sometimes white, pink, or purple). The flower heads are borne in dense corymbs. The ray flowers are threadlike and fluff-haired, leading to the common name. The narrow lanceolate bracts are pointed, denticulate only at the top and glandular hairy. The flowering period is from May to November in the northern hemisphere.
Ageratum has evolved a unique method of protecting itself from insects: it produces a methoprene-like compound which interferes with the normal function of the corpus allatum, the organ responsible for secreting juvenile hormone during insect growth and development. This chemical triggers the next molting cycle to prematurely develop adult structures, and can render most insects sterile if ingested in large enough quantities.
Flossflower, Bluemink, Ageratum houstonianum, Kentlands Photowalk, Gaithersburg, Maryland, USA IMG 4478
Cannon PowerShot G11 Camera, f/4.5, 1/160 sec., ISO-320, 30 mm, No Flash
Photograph by Roy Kelley
Roy and Dolores Kelley Photographs