Baptisia lactea var. lactea

Native

Minnesota special concern species

Dry to moderate moisture. Prairies, savannas, open, upland woods, railroads. Full to partial sun.

June to July

White

40″ to 80″

This is a 40″ to 80″ tall, erect, long-lived, perennial forb that rises from a deep taproot and rhizomes.

The stems are unbranched in the middle and below, with ascending branches near the top below the inflorescence. They are light green or reddish-purple, hairless, and covered with a whitish, waxy bloom (glaucous).

The leaves are alternate and on leaf stalks that are a little over ¼″ to ½″ long. There are a pair of 3 ⁄16″ to ⅜″ long, leaf-like appendages (stipules) at the base of the leaf stalk. The stipules are usually deciduous, with some falling off as the plant matures, but usually a few remaining on the plant at maturity. The leaves are divided into 3 leaflets. The leaflets are inversely lance-shaped or inversely narrowly egg-shaped, attached at the narrower end. They are 1¼″ to 2⅜″ long, and up to ¾″ wide. The upper side grayish-green or bluish-green and hairless. The underside is paler, hairless and glaucous. The margins are untoothed.

The inflorescence is an erect, 8″ to 24″ long, spike-like cluster (raceme) of large, showy flowers at the end of the stem and branches. The central raceme is longer than the lateral ones. Below the inflorescence there are small, leaf-like appendages (bracts). The bracts are are ¼″ to ½″ long and fall before or when the plant is in flower.

The individual flowers are ½″ to ¾″ long and white. They are on ⅛″ to ⅜″ long flower stalks. There are 5 green sepals united at the base into a cylinder-shaped, 5 ⁄16″ long calyx tube, then separated at the tip into an upper and a lower lip. The upper lip is unlobed or notched. The lower lip is divided into 3 triangular lobes. There are 5 white petals. The petals form a butterfly-like corolla, as is typical of plants in the Pea family. They are organized into a broad banner petal at the top, two narrower, lateral, wing petals, and between the wings two petals fused into a keel. The banner is upright, folded back along the edges, notched in the middle, and shorter than the wings or keel. The wings and keel are straight. There are 10 stamens. The stamens are distinct, not fused together. The flowers are pollinated by bumble bees (Bombus spp.). There is no fragrance.

The fruit is a large, drooping seedpod. It is ellipse-shaped to oblong, inflated, 1″ to 1½″ long, and 5 ⁄16″ to ½″ wide. It is green at first, turning brown as it ripens and black when it dries.

Longbract wild indigo (Baptisia bracteata var. leucophaea) is a much smaller plant, no more than 24″ in height at maturity. The stipules are larger, ⅜″ to 1¼″ long, and are persistent, remaining on the plant at maturity. The floral bracts are much larger, ⅜″ to 1¼″ long, and remain on the plant at maturity. The flowers are creamy yellow and appear earlier, May to June.

Taxonomy
Most sources still use the former name, Baptisia alba var. macrophylla, for this plant.