Arnoglossum atriplicifolium

Native

Wood edges, prairies, roadsides. Full to partial sun.

July to September

White to cream-colored

3′ to 9′

This is a 3′ to 9′ tall, erect, perennial forb that rises on a single stem from somewhat fleshy roots.

In the spring it forms a rosette of a few basal leaves. The basal leaves are triangular egg-shaped, up to 8″ long, and up to 6″ wide. They are on slender leaf stalks that are up to 6″ long, have a U-shaped groove on the upper side, and are sometimes purplish at the base. The blades are usually heart shaped, sometimes squared off, at the base. They are often shallowly palmately lobed, with usually broadly pointed lobes. They are palmately veined with 7 to 10 main veins. The upper surface is dark green and hairless. The lower surface is pale green, hairless, and conspicuously covered with a whitish, waxy bloom (glaucous). The margins are coarsely, irregularly toothed.

In the late spring a single flowering stem rises from the center of the rosette. The stem is erect, round in cross section, smooth or finely grooved, leafy, glaucous, and unbranched below the inflorescence.

Stem leaves are alternate. Lower stem leaves are on long leaf stalks and similar to basal leaves, becoming smaller and on shorter leaf stalks as they ascend the stem. Upper stem leaves are short-stalked, egg-shaped to triangular egg-shaped, sometimes narrowly egg-shaped, coarsely toothed, and tapered at the base.

The inflorescence is a branched, flat-topped, up to 8″ wide cluster (corymb) of up to 100 or more flower heads at the end of the stem and rising from the upper leaf axils.

The whorl of bracts at the base of the flower head (involucre) is more or less cylindrical, 5 ⁄16″ to ⅜″ long, and about ⅛″ in diameter. There is a single series of 5 or 6 linear, overlapping, greenish-white bracts. The bracts are rounded on the back, not keeled.

There are 5 white or cream-colored, rarely pinkish, disk florets and no ray florets.

The fruit is a ⅛″ to ¼″ long, spindle-shaped or egg-shaped achene containing a single seed. It is dark brown and has 10 ribs.

Sources: 7.

False Indian plantain (Arnoglossum plantagineum) basal leaves are triangular to arrow-shaped, with spreading, outward-pointing lobes at the base but otherwise unlobed.

Great Indian plantain (Arnoglossum reniforme) stem is angled in cross section and is not glaucous. Basal leaves are larger and kidney-shaped. The underside of the leaf is not glaucous or only slightly glaucous.

Tuberous Indian plantain (Arnoglossum plantagineum) stem is angled in cross section and is not glaucous. Basal leaves are larger and kidney-shaped. The underside of the leaf is not glaucous or only slightly glaucous.