Tradescantia occidentalis var. occidentalis

Native

Dry or moderate moisture. Prairies, meadows, roadsides. Full sun.

June to July

Bright blue to rose or magenta

8″ to 24″

This is a 16″ to 40″ tall, erect, perennial forb that rises on 1 to many stems from thick, fleshy, fibrous roots.

The stems are erect or ascending, often branched, usually hairless, green, and covered with a whitish, waxy or powdery film (glaucous). There are 2 to 6 nodes on the stem and up to 10″ between nodes.

The leaves are alternate, linear, 3½″ to 12″ long, and 1 ⁄16″ to ½″ wide but usually less than ⅜″ wide. They are hairless, bright green, and glaucous. The upper leaves are as narrow or narrower than the part of the leaf that surrounds the stem when it is opened and flattened. The base of the leaf sheaths the stem. The tip tapers to a point with concave sides along the tip. The margins are untoothed and rolled inward toward the upper side.

The inflorescence is a tight, umbrella-like cluster of up to 25 flowers arising from the same point. They appear at the end of the stem, at the ends of branches, and often on long stalks rising from the leaf axils. A pair of bracts below the inflorescence are similar to the leaves and about the same size, 2″ to 8″ long.

The flowers are 1″ to 1½″ wide. They are on ⅓″ to 1⅛″ long stalks which droop when in bud, becoming erect when the flower opens. The flower stalks and sepals are sparsely hairy with minute, glandular hairs. The sepals may have a tuft of hairs at the tip. The 3 petals are bright blue to rose or magenta and broadly egg-shaped. There are 6 stamens with bright yellow anthers. The petals last only one day, opening in the morning then turning to jelly in the mid-day heat. The central flowers bloom first. There is no floral scent.

The fruit is a papery, nearly round to oblong capsule ¼″ or less in diameter with 2 to 6 seeds.

Bracted spiderwort (Tradescantia bracteata) stems are usually unbranched and bright green. The leaves are bright green and keeled, not rolled inward. Neither the stems nor the leaves are glaucous. The bracts are 2″ to 12″ long, often longer and wider than the leaves. The sepals and flower stalks are densely hairy with both long and short hairs.

Ohio spiderwort (Tradescantia ohiensis) is a taller plant, 16″ to 40″ tall at maturity. The stems are glaucous. The leaves are glaucous and flat, not rolled inward. The bracts are 2″ to 8″ long and no wider than the leaves. The sepals and flower stalks are sparsely hairy with minute, glandular hairs.