Lactuca floridana (L.) Gaertn.
Family - Asteraceae
Stems - To +2.5m tall, purple, glabrous, single from the base, branching in inflorescence, from a taproot, with pure-white milky sap, erect, herbaceous.
Leaves - Alternate, sessile. Basal leaves toothed(dentate), pinnately lobed, to +15cm long, +9cm broad, terminal lobe triangular. Cauline leaves toothed, lobed to unlobed, glabrous, with triangular, sagittate terminal lobe.
Inflorescence - Paniculate arrangement of flower heads at the apex of the main stem.
Involucre - Vase shaped to cylindric. Phyllaries imbricate, green with purple apices.
Ray flowers - 10-16 flowers per head. Corolla light blue, sometimes whitish. Ligules to 6mm long, apex toothed. Flower head +/-12mm broad, when fully opened. Achenes brown, to 5mm long, ribbed, typically with short beak. Pappus to +/-8mm long, of white capillary bristles in more than one series.
Disc flowers - Absent.
Flowering - August - October.
Habitat - Open woods, thickets, disturbed sites, waste ground, streambanks, roadsides, railroads.
Origin - Native to U.S.
Other info. - Although the
inflorescence can have over 100 flower heads at once, these open just a
few at a time. The plant will secrete a pure-white milky juice if bruised. There are
a few variations which are mostly differentiated on leaf shape and/or flower
color. I won't go into those here.
Photographs taken at the Kansas City Zoo, 10-25-99, and in Brown Summit, NC., 9-21-02.