Flower:

Single short-stalked flowers arising from the leaf axils at the top of the plant and along branching stems. Flowers are funnel-shaped, ¾ to 1+ inch long, up to 1 inch across, pinkish-purple with 5 spreading lobes that are finely hairy around the edges, the upper 2 lobes slightly smaller than the lower 3. The inside of the tube is white with darker reddish-purple spots and usually a pair of pale yellow stripes. The 4 hairy, white-tipped stamens and a single white style are about as long as or slightly longer than the floral tube.

The calyx cupping the flower is hairless and has 5 sharply pointed triangular to awl-shaped lobes that are 1/3 to half as long as the calyx tube. Flower stalks are hairless and shorter than the calyx.

Leaves:

Leaves are opposite, 1 to 2 inches long, linear to narrowly lance-linear, toothless, stalkless, with a prominent central vein, may be rough textured on the upper surface and are sometimes purple tinged. Smaller leaves may develop in the axils. Stems are angled and smooth or slightly rough, usually branched, erect to ascending.

Fruit:

Fruit is a shiny globular capsule about ¼ inch across, containing many tiny, dark brown seeds.

Notes:

Purple False Foxglove is uncommon in Minnesota, primarily found in saturated or seasonally wet meadows with sandy soil. It is easily confused with the much more common Small-flower False Foxglove (Agalinis paupercula, formerly A. purpurea var. parviflora) with which it may grow. A. paupercula is generally a smaller plant with flowers about half the size (not more than ¾ inch long, usually ½ to 2/3 inch), flowers typically a lighter pink, the stamens and style can be shorter than the floral tube, and its calyx lobes are shorter than to about as long as the calyx tube, where A. purpurea flowers are at least ¾ inch long, typically a deeper purplish-pink, stamens and styles are usually at least as long as the floral tube, and calyx lobes are not more than half as long as the tube. When flowers are not present it is very difficult to distinguish the two.

A. purpurea is also similar to Slender-leaved False Foxglove (Agalinis tenuifolia), which is most easily distinguished by its long flower stalk. Agalinis spp. are partially parasitic, though it is unknown (to me) what species are host plants. This trait has moved the Agalinis genus from the Scrophulariaceae (Figwort) family to the Orobanchaceae (Broomrape) family.

Of note is that prior to A. purpurea and A. paupercula being split into separate species, we had dozens of photos all simply identified as A. purpurea without regard to var. Chances are those taken around the Anoka Sandplain could be either and those taken in other parts of the state are more likely A. paupercula, but without clear diagnostic images of the flowers there is no reliable way to distinguish them at this point.