Flower:

Flowers are tubular, irregular trumpet shaped, ½ to ¾ inch (1 to 2 cm) long, borne in pairs from opposite leaf axils along the stem. Petals are blue to violet, covered with fine hairs with a broad, wavy lower lip patterned with blue dots against a white throat. The upper lip forms a rounded hood over the mouth of the tube. Flowers typically bloom 2 to 3 pairs at a time from axils a bit below the tip of a stem. The calyx holding the flower has a small ridge-like protuberance at the top.

Leaves and stems:

Leaves are ¾ to 2¼ inches (2 to 6 cm) long, ¼ to ¾ inch wide, opposite, lance-like to more oval and oblong, toothed with rounded or bluntly pointed teeth, veiny, somewhat glossy on the upper surface with soft short hairs on the underside, and little or no leaf stalk. Stems are square with fine rough hairs on the angles. Branches are many, weak but erect, often supported by surrounding vegetation.

Fruit:

Fruit is a spherical cluster of 4 brown nutlets that forms inside the persistent calyx.

Notes:

Marsh skullcap is a common species of wetlands, lakeshores and riverways throughout Minnesota but not always apparent. The progression of seasonal growth and blooming branches are intertwined with other wetland species making them difficult to spot (and more difficult to photograph!). Another skullcap found in the same habitat is Mad-dog Skullcap (Scutellaria lateriflora), which has racemes of flowers about half the size and without the blue-spotted lower lip, and with broader leaves.