BULL THISTLE, Cirsium
vulgare (Savi) Tenore. 1, portion of stem showing leaf attachments;
2, upper portion of stem; 3, flower head; 4, seed.
Biennial, reproducing by seed. In first year forms rosette with
large fleshy taproot. Stem second year, 2 to 4 feet (0.6 to 1.2
m) tall, heavy, often branched, more or less hairy. Leaves deeply
cut, spiny, green on both upper and lower surfaces despite presence of
hair. Leaf bases running down stem to give stem winged appearance. Spines
on lobes of leaves and stems. Flower heads compact, 1 to
2 inches (2.5 to 5 cm) in diameter, rose to reddish-purple; each head surrounded
by spiny-tipped bracts. Seeds straw-colored, striped with brown,
ridged around one end, tipped with an easily detached plumose pappus. Found
in pastures, meadows, and other uncultivated land. Does not survive cultivation.
TALL THISTLE, Cirsium altissimum (L.)
Spreng. Similar to above. Biennial, reproducing by seed. Stems
3 to 10 feet (0.9 to 3 m) tall. Leaves may vary from entire to lobed,
and are dark green on upper surface and white woolly on lower surface.
Flower heads about 1 inch (2.5 cm) in diameter, rose-purple.