SPOTTED KNAPWEED, Centaurea
maculosa Lam. 1, portion of stem with leaves; 2,
upper portion of stem with flower heads; 3, single flower head.
Biennial, reproducing by seed. Stems erect or ascending,
slender, 1 to 3 feet (30 to 90 cm) tall, hairy, branching. Leaves
alternate, deeply divided into narrow segments, covered with short hairs,
much reduced in size near top of the plant. Flower heads
about 3/4 inch (1.9 cm) across, numerous, consisting only of pink to purple
disk flowers; heads both terminal and in axils of upper leaves; each head
surrounded by leaflike bracts with dark tips bearing a fringe of bristly
hairs. Seed brownish, 1/8 inch (3 mm) long, notched on one side
of base, with a short tuft of bristles on tip end. Found in pastures,
fields, and roadsides, especially those with dry, gravelly, or sandy soils.