Conium maculatum L. - Poison Hemlock
Family - Apiaceae
Stems - To 3m tall, herbaceous, green with purple or black spots, sometimes entirely purple, often glaucous, glabrous, erect, from large taproot.
Stem.
Leaves - Alternate, large, to 40cm long, about as broad as long, ternate, glabrous, broadly ovate in outline. Leaflets pinnatifid. Lobes serrate.
Inflorescence - Multiple compound umbels terminating the stems. Umbels and umbellets subtended by attenuate bracts to 5mm long. Rays glabrous. Flowers +/-15 per umbellet.
Flowers - Petals 5, white,
subequal but typically with one petal larger than the others, glabrous,
to 1.2mm long, 1mm broad, cuneate at base. Apex of petal apiculate with the
apiculus curving adaxially. Margins of petal folding slightly downward.
Stamens 5, alternating with petals. Filaments to 1mm long, white, glabrous.
Anthers pale yellow to whitish, .15mm broad. Stylopodium present, slightly
flattened, greenish.
Flowers close-up.
Flowering - May - August.
Habitat - Waste groung, disturbed sites, pastures, open fields, low ground, railroads, roadsides.
Origin - Native to Europe.
Other info. - Although this
plant may smell like fennel (Foeniculum sp.) , or Finocchio
in Italian, when bruised or crushed, it should not be eaten as it is very
toxic.
No other species in the family has such large and divided leaves as C. maculatum,
so the plant can be easily distinguished from a distance. It is a very
common weed in Missouri.
Photographs taken at the Kansas City Zoo, 5-22-00, and in Eminence, MO., 6-6-03.
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