Cynanchum laeve (Michx.) Pers.
Family - Asclepiadaceae
Stems - Twining, climbing, herbaceous, often reddish, with milky sap, with villous pubescence in lines on the stems.
Stem at a node.
Leaves - Opposite, petiolate.
Petioles to +7cm long, reddish-green. Blades typically glabrous but also
variously pubescent, dark green with evident veining above, cordate, ovate,
acute to acuminate or apiculate, to +/-10cm long, +/-8cm broad.
Inflorescence - Axillary umbellate cyme with +/-30 flowers. Peduncles to 5cm long, pubescent. Pedicels to 1cm long, pubescent.
Inflorescence.
Flowers - Corolla deeply
5-lobed. Lobes whitish, 7mm long, -3mm broad, erect to spreading, glabrous.
Corona of 5 appendages. Appendages white, erect, to 6mm long, expanded
at base, tapering into 2 linear lobes at apex. Calyx 5-lobed. Lobes green
with some purple, ovate-lanceolate, to 3mm long, sparse pubescent.
Flower close-up.
Again.
Fruit - A large follicle, 10-11cm long, 4cm wide at widest point, teardrop-shaped, glabrous. Seeds winged, to +8mm long. Coma to 4cm long, white.
Follicle.
Flowering - July - September.
Habitat - Disturbed sites, along fences, waste ground, roadsides, railroads, thickets, open woods.
Origin - Native to U.S.
Other info. - Being from
the Asclepiadaceae, this plant will "bleed" a white,
latex-like secretion when pinched or bruised. Don't get this in your eyes
nose or mouth as it can be irritating or harmful.
This plant is seen as a weed by
some but it always dies back in the fall leaving the large fruits hanging
until they split open dorsally. The seeds can be carried a great distance
by the wind.
This species can be found throughout most of Missouri but is apparently absent from the south-central Ozark region.
Photographs in St. Louis, MO., 7-28-03.
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