Trumpetweed

Eupatorium fistulosum

Composites, that is, plants of the Sunflower Family, Asteraceae, very commonly bloom in the late summer and fall.  Trumpetweed is an example, with its huge heads of pink-purple flowers in late summer.  As we saw earlier, what most people call flowers on plants of this family are really clusters of flowers called heads.  In the Sunflower Family, there are usually two kinds of flowers; a central cluster of tubular disc flowers, surrounded by a sunburst of ray flowers, as seen in sunflowers or daisies.  In trumpetweed, however, all the flowers are disc flowers, and each head contains few to many such flowers.  Each plant has many such heads, as seen in the pictures at left and below.  The flowers produce much nectar and are popular with bees and butterflies.  As I am typing this, the trumpetweeds in my yard, outside my window, are being visited by a steady stream of bees, and an occasional monarch butterfly.

Trumpetweed is commonly also called joe-pye weed.  A number of other members of the genus with purple flowers are also called joe-pye weeds.  All joe-pye weeds differ from most members of Eupatorium in that they have whorled leaves, that is three or more leaves arising from the same spot on the stem.  When crushed the leaves give off the scent of vanilla.  Of the joe-pye weeds, trumpetweed has the most leaves in each whorl, up to seven, and is also the tallest, up to six feet high.  It also differs from other joe-pye weeds in that stems are hollow, at least towards the top.  The species name, fistulosum means hollow.

The name of the genus, Eupatorium, honors Mithridates Eupator, King of Pontus, who lived from 132 to 163 BC.  I am not sure why Linnaeus, who named the genus, wanted to honor King Eupator.  The joe-pye weeds, that is the members of Eupatorium with whorled leaves, are different enough from other members of the genus that some botanists now put them in their own genus, Eutrochium.  That name comes from the Greek eu- meaning truly and trocho meaning a wheel, and refers to the whorled leaves like spokes of a wheel.

The common name of the group is also interesting.  It honors Joe Pye, an American Indian of colonial times who was said to be an accomplished healer with joe-pye weeds being among his mostly commonly used medicinal herbs.  They plants were formerly, and sometimes still are used to make a tea used to increase urination and as an astringent to stop bleeding.

The genus Eupatorium is a huge one, with over 500 species all over the world, but the greatest diversity is in the American tropics.  Trumpetweed is found from Maine to Michigan, south to Florida in the east and to Illinois, Missouri, Oklahoma, and Texas in the west.  It favors low wetlands, flood plains, streamsides, moist meadows and bogs.  In Wildwood, it is common in the flood plain of Connoly's Run, in the northern butterfly garden.  Although it has a huge flower stalk, only a few of the flowers are open at any one time.  Thus, it puts on a long-lasting show in the butterfly meadow.

GGC