Pearl Snaps

Stories of a cowgirl living life by her own lights


Weedy Wednesday: Henbit



Henbit (Lamium amplexicaule L.) and purple deadnettle (Lamium purpureum L.) are winter annual species of the same genus and are frequently confused with each other. Both species are often called henbit. These weeds germinate in the fall and sometimes in the spring. They are found throughout the eastern United States and thrive in both cool-season and warm-season forage grasses. Both species also grow in fine turf, orchards, gardens, landscapes, and cultivated crops.

Purple Deadnettle

Henbit flowers are pink to red and occur in clusters, 6 to 10 inches tall in the upper leaf stalks. Purple deadnettle flowers occur near the tops of the plant and are less purple than henbit flowers. The most striking difference is that the purple deadnettle’s upper leaves and stems are very red in appearance compared to henbit.

These weeds are relatively easy to control with several herbicides; however, mowing is ineffective. Consult your local Cooperative Extension Service personnel for herbicidal control in your area.

William W. Witt, PhD, a researcher in the department of Plant and Soil Science at the University of Kentucky, provided this information.

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Weedy Wednesday: Bitter Sneezeweed

A few weeks ago while visiting Ryan Goodman (@AR_ranchhand, blog), I noticed  a weed growing in the pastures of the Middle TN Research and Education Center.  It was an unusual, yellow-flowered plant I had never seen before.   It turns out it was actually a fairly common pasture weed in Tennessee and other southern states.  Upon further research, I came to learn that this weed was known as bitter sneezeweed.  The Toxic Plants of Texas website provides some very useful information about this weed.

Bitter sneezeweed (Helenium amarumis an erect, upper-branching annual, 10 to 20 inches tall with narrow leaves, alternating on the stem. The flowers are noticeable in the late spring or summer and are located at the end of each branch.

Two varieties of this plant are identical except for the flower color: one is all yellow; the other is yellow with a red-brown center. Each bloom has about eight cleft ray flowers (petals) with three lobes, often bending downward at maturity.

In some years, the lower leaves are lost, new growth occurs up the stalk and new flowers appear in the fall. The entire plant has a strong odor and is bitter to the taste.

Photo courtesy of Jerry A. Payne, USDA-ARS

Bitter sneezeweed is found from Virginia to Florida to Texas and extending into southern parts of adjacent northern states; most abundant in coastal plain where it may be very abundant weed in pastures, roadsides and waste places.

A sesquiterpene lactone is responsible for the toxicity of bitter sneezeweed, which is greatest at time of lowering. This bitter plant is seldom consumed at a level high enough to produce clinical signs. However, it has been responsible for bitter, undrinkable milk and is suspected to be the cause of unpalatable meat from calves slaughtered off the range. The toxin is stable in plants contaminating hay.

Signs of bitter sneezeweed poisoning include: Weakness; Incoordination; Vomiting; Salivation; Diarrhea; Grinding of teeth.

Avoid cutting hay containing a large amount of bitter sneezeweed. Do not feed hay containing any of the plant to lactating dairy cows. Do not slaughter grass-fed cattle from a pasture that contains bitter sneezeweed.

Severe infestations may be controlled with broadleaf herbicides such as 2,4-D or Grazon P+D® at 0.5 to 1.0 pound a.i./acre in the spring with good growing conditions.

Additional information can be found on the Poisonous Plants of the Southern United States website.


Weedy Wednesday: Spiny Pigweed

Photo courtesy of John D. Byrd, Mississippi State University


Spiny pigweed (Amaranthus spinosus L.), also known as Spiny amaranth is a warm season annual native to the Tropical Americas.  It is not considered a poisonous plant.  Spiny pigweed is distributed widely across the United States and grows most frequently along fence borders, feeding and watering sites, and other compacted areas. Spiny pigweed can sometimes infest entire overgrazed pastures. Seeds germinate in late spring or early summer. Stems are reddish, stout, and branched, and mature plants can grow to three feet tall. Sharp spines that inhibit grazing are found in stem axils and are surrounded by dense clusters of female flowers. The male flowers are long terminal clusters.

Spiny pigweed control is relatively easy when herbicides are applied to plants less than 12 inches tall. Mowing and hand weeding are effective if done before flower production to prevent seeding. Consult your local Cooperative Extension Service personnel for herbicidal control in your area.

William W. Witt, PhD, a researcher in the department of Plant and Soil Science at the University of Kentucky, provided this information.


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