Blue Porterweed


A firm foundation, with floral spikes rising up like a cathedral…

The Blue Porterweed, Stachytarpheta jamaicensis, is a herbaceous, perennial shrub that likes the sand of costal dunes, pine rocklands, and disturbed sites.  Porterweed is a low growing, sprawling plant that forms a circular mat that is up to six feet in diameter. A  foot or two high this species makes a successful ground cover.  At the base of the plant are gray brown woody branches  that become herbaceous at the top.  Dark  green leaves, 1 to 5 inches in length are positioned opposite from one another on the branches.  Leaf shape is lanceolate to ovate.  Coarse teeth are on the leaf margins.

Branches merge into long floral spikes that can be 3 feet in length. Spikes are initially erect then arch downward. Minute, light blue, five petal, tunnel flowers appear in clusters along the floral spikes.  Flowers are about ¼ of an inche in diameter. Blooming occurs year around.

In the U.S. Porterweed is found only in Alabama and Florida. In this State, it is distributed in the Southern counties and in a few Central counties in Florida. This species is often confused with Nettleweed, S.cayennensis, which is native to the old world. The plant is the host plant for the nectar source to the Gulf Fritillary and Monarch butterflies.

The specimen in the picture is in my front yard.

Dorothy Rodwell