Flower:

Flowers are in whorls of 4 to 10 at the top of the plant and at leaf axils in the upper half of the stem. Individual flowers are ½ to ¾ inch long, pinkish-purple, irregular with 2 lips at the end of a long, slender tube. The upper lip is rounded like a hood, darker colored than the tube and densely covered in short hairs. The lower lip is sac-like, cleft into 2 spreading, oblong lobes. The small lateral lobes and lower lobes are white near the mouth of the sac, spotted with dark pinkish-purple. Inside the tube are 4 stamens. The calyx surrounding the base of the tube is 5-lobed, densely hairy, and up to about 1/3 inch long.

Leaves and stems:

Leaves are opposite, up to 1 inch long and nearly as wide, hemispheric to nearly round to kidney-shaped, rounded at the tip, straight across to somewhat wedge-shaped at the base, with rounded teeth along the edges and sometimes with a few shallow lobes. Surfaces are sparsely hairy; lower leaves are stalked, becoming stalkless about midway up the stem and reduced to bracts on the upper stem. Stems are erect to ascending, square, rough-textured from minute stiff hairs, green to reddish, and typically many-branched near the base.

Fruit:

The calyx persists and holds 4 bristly nutlets, each containing a single seed.

Notes:

Henbit is a garden escapee that is not yet very widespread in Minnesota, but is considered invasive in many areas of the US. Best to nip this one in the bud! It is likely already more widespread than the distribution map indicates—one of my own neighbors has been battling volunteers in his yard for some years now. An annual, a single plant generates hundreds of seeds which stay viable for several years. The seeds drop near the mother plant and masses of seedlings can pop up the following spring. There are no Lamium species native to North America, but there are several introduced species (not counting the numerous cultivars) available in the nursery trade, all of which may escape cultivation. Yellow Deadnettle (Lamium galeobdolon) and Spotted Deadnettle (Lamium maculatum) have already arrived here. Henbit is more or less the size of Creeping Charlie (Glechoma hederacea), but with larger flowers that are more pinkish-purple and have longer tubes. The spot pattern on Henbit flowers is also different, with the single dots on the lateral lobes and a larger dot near the base of the split lower lobe always reminding me of a face on some strange cartoon character. So my new common name is Cartoon Flower :-)