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Poison Hemlock
Apiaceae (=
Umbelliferae), the parsnip family
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Background
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 Poison
hemlock is native to Europe. It contains highly poisonous alkaloids toxic to
all classes of livestock and humans. It has poisoned many who have mistaken
it for parsley. Poison hemlock is often found on poorly drained soils,
particularly near streams, ditches, and surface water.
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Description
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 Poison
hemlock is a biennial that grows up to 10 feet
tall. Stems are stout, hollow, ridged, and mottled with purple spots. Leaves
are shiny green, 3 to 4 times pinnately compound, and
clasp the stem at the
obvious nodes. Crushed foliage has a disagreeable, mousey odor. Flowers are
small, white, and borne in umbrella-shaped clusters about 3 inches across
in early summer. Seeds are ridged and flattened, with 2 seeds borne
together. The plant has a thick, white
taproot.
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Distribution
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 It
grows throughout the U.S. except from eastern Montana to northeastern
Minnesota and south to Nebraska. It has an extensive presence in Idaho. |
Control
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A biological control agent (a
defoliating moth) provides good to excellent but inconsistent control.
Herbicides are also available.
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© 1999 University of Idaho:
Text and photographs for these pages from Idaho's Noxious Weeds, by
Robert H. Callihan and Timothy W. Miller (revised by Don W. Morishita
and Larry W. Lass).
Please contact: Ag Publishing, University of Idaho, Moscow,
Idaho 83844-2240; 208 882-7982 visit the Resources for Idaho website at
http://info.ag.uidaho.edu, for more information about this or other
publications.
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Jointed Goatgrass
Poaceae
(=Gramineae), the grass family
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Background
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 Jointed goatgrass is native of southern Europe and western
Asia. It is also closely related to wheat that both species can interbreed.
It is difficult to distinguish from wheat until
spikes appear. It spreads
exclusively by seed. Jointed goatgrass grows best in cultivated fields, but
can also invade grassland. |
Description
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Jointed goatgrass is a winter
annual, but about 5
percent of a populations may be spring annuals. Leaves are grass-like, up to
a 1/2-inch wide, and have evenly spaced fine hairs along the leaf edges and
down the sheath opening. The ligule is short and
membranous;
auricles are
short and hairy. Stems can grow up to 4 feet tall and are tipped with
slender, cylindrical spikes that appear to be a series of joints stacked on
top of each other. Reddish to straw-colored spikes emerge in May to June,
and uppermost joints are tipped by straight awns. Up to 3 "seeds" are
enclosed in each joint. |
Distribution
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J ointed goatgrass is found in all major U.S. winter
wheat production regions---from Texas to South Dakota and eastern Montana,
and in portions of the Northwest and Utah.
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Control
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No biological control agents are available for jointed goatgrass, and no herbicides are available that can selectively control it
in winter wheat; spring tillage and general grass killers provide excellent
control.
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© 1999 University of Idaho:
Text and photographs for these pages from Idaho's Noxious Weeds, by
Robert H. Callihan and Timothy W. Miller (revised by Don W. Morishita
and Larry W. Lass).
Please contact: Ag Publishing, University of Idaho, Moscow,
Idaho 83844-2240; 208 882-7982 visit the Resources for Idaho website at
http://info.ag.uidaho.edu, for more information about this or other
publications.
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