Pterocaulon pycnostachyum

Pterocaulon pycnostachyum, with the common names dense-spike blackroot,^[4] fox-tail blackroot or coastal blackroot, is a flowering plant species native to the U.S. southeast coastal plain in the states of Alabama, Mississippi, North Carolina, Florida, Georgia, and South Carolina. It can be found in pinelands, ditches, depressions, and fields.^[5][6]

Pterocaulon pycnostachyum
Conservation status
Secure  (NatureServe)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Asterales
Family:	Asteraceae
Genus:	Pterocaulon
Species:	P. pycnostachyum
Binomial name
Pterocaulon pycnostachyum (Michx.) Elliott
Synonyms[2][3]
Chlaenobolus pycnostachyum (Michx.) Cass. Chlaenobolus spicatus Cass. Conyza pycnostachya Michx. Gnaphalium undulatum Walter Pterocaulon undulatum C. Mohr

Description

Pterocaulon pycnostachyum is a perennial herb up to 80 cm (31 inches) tall. Stems and the underside of leaves are covered with a thick, white layer of woolly hairs. Flower heads are crowded into a densely packed spike at the tips of the branches. Each head has as many as 50 small yellowish flowers. The plant is monoecious, meaning that some of the flowers have male stamens, while female pistils are in separate flowers in the same head.^{[5][7][8][9][10]}