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Thursday, October 30, 2014

Blooming Mist

All members of the Aster family, the Eupatorium genus of flowering plants are characterized by their medium-tall to tall stems and triangular, toothed leaves, topped with a cluster of small composite flowers.   They grab our attention in the fall as their blooms are prolific, like small clouds of mist, on which late-season butterflies, bees, and moths are eager to gather.  It’s easy to see why they are commonly called mistflowers, but they are also called bonesets, thoroughworts, and snakeroots.

To add to the mystery, the classification of this tribe of plants is the subject of ongoing research, and many species that were once grouped under Eupatorium have recently been moved to other plant families, or genera.  Conoclinium, the mistflowers, is a genus that includes only 4 species native to North America, and having blue to purple flowers.  Ageratina, or snakeroots, has over 250 species, and they grow mainly in warmer regions.

Commonly named for medicinal uses, various members of this plant family have been used to treat fevers and other health ailments.  Boneset alludes to the use of the plant to stimulate calcium production to speed the healing of broken bones, although the name may have also come from its use to treat dengue fever, also called breakbone fever due to the pain it inflicted.  Thoroughwort is named for its ‘perfoliate’ leaves, or the way the stem appears to pierce (or go through) the leaf.

Blue mist flower, Conoclinium coelestinum

In the hill country, Blue mistflower (Conoclinium coelestinum) is also called wild ageratum or blue boneset. Forming fairly large, bushy clumps 1-4 ft tall on moist soils near streams and in low meadows, its opposite leaves are triangular, wrinkled, somewhat thick, and smell a bit like tomato plants when crushed.  Preferring sun to partial shade, its lavender to sky-blue clusters of flowers bloom from October to December, subject to the first frost.

Gregg’s mistflower, Conoclinium greggii

Named after the 19th century explorer and naturalist Josiah Gregg, Gregg’s mistflower (Conoclinium greggii) is native to west Texas but spreading eastward to the Edwards Plateau.  Also called palmleaf thoroughwort or purple palmleaf mistflower, this 1.5 to 2 ft tall perennial has puffy, purple-blue flower heads from March through November.  Often attracting impressive numbers of nectaring Queen butterflies in the fall, this plant is found along seasonally flooded streambeds and has a lighter green, more delicate foliage.

Shrubby boneset, Ageratina havanensis

Also called Havana snakeroot, white mistflower, and white shrub mistflower, Shrubby boneset (Ageratina havanensis) is a rounded, open woody shrub, 2-5 ft tall, and multi-branched.  Its leaves are triangular with toothed edges, relatively thin, and about 2 inches long.  Blooming in October and November, the profuse flowers are fuzzy, pinkish-white, and very fragrant. Deciduous and drought-tolerant, Shrubby boneset is found on rocky hillsides and bluffs in the southern half of hill country.  Butterflies, moths, and hummingbirds, love the upright, fuzzy flower heads, and this plant is the larval host plant for the difficult to identify Rawson’s metalmark. 

Late boneset, Eupatorium serotinum

Late boneset (Eupatorium serotinum), also called late-flowering thoroughwort or white boneset, is an open, woody shrub up to 3 ft tall, with leaves up to 5 inches long, opposite and coarsely toothed.  Blooming in October and November, it likes partial shade, and is found in the eastern to central portion of the state, usually in meadows, woodland edges, near ponds or moist stream banks.   

Regardless of their classification, these native fall bloomers are a haven for wildlife.  Seek them out when hiking along your favorite trail – their intricate, fuzzy blooms beckon you to explore them up close!