Symphyotrichum ericoides var. pansum

Native

Dry to moderate moisture. Prairies, meadows. Full sun.

July to September, rarely October

White

6″ to 36″

This is a 6″ to 36″ tall, erect, perennial forb that rises rises in a dense cluster of stems from a corm-like caudex.

The stem is ascending to erect. It is moderately to densely covered with straight, stiff, sharp hairs that are pressed flat against the stem, making the stem rough to the touch. It is sometimes almost hairless toward the base. It is green when young, becoming grayish-brown to brown when the plant matures.

The leaves are of two types. At the base of the plant the leaves are ½″ to 2″ long, ½″ to 1″ wide, inversely lance-shaped or spatula-shaped, with the attachment at the narrow end. They are usually untoothed and rough to the touch. They are rounded at the tip and taper gradually to a narrow base where they are attached to the stem without a leaf stalk. The upper surface is usually sparsely hairy but may be hairless. By the time the plant is in flower the basal leaves have withered. The stem leaves are alternate, numerous, untoothed, rigid, and linear to lance-shaped. Near the base they are ½″ to 1½″ long and up to ⅛″ wide. They become progressively smaller as they ascend the stem.

The inflorescence is a dense cluster of 1 to 200 flower heads near the top of the plant. The flower heads are mostly on one side of curving, widely-spaced branches.

The flower heads are mostly ¼″ to ½″ in diameter. The whorl of bracts at the base of the flower head (involucre) is broadly bell-shaped. Each bract in the involucre has a minute, white to yellowish or purplish spine at the tip. There are 8 to 20 (usually 10 to 18) white, ⅛″ to ¼″ long ray florets and 6 to 20 (usually 6 to 12) yellow disk florets. The disk florets become brown with age.

The fruit is a tiny seed-like achene with a tuft of whitish, ⅛″ long hairs at the tip.

Hairy white oldfield aster (Symphyotrichum pilosum var. pilosum) flower heads are larger, mostly 9 ⁄16″ to ¾″ or more in diameter. The involucral bracts are not spine-tipped. The ray florets are longer, 3 ⁄16″ to ⅜″ long.

White heath aster (Symphyotrichum ericoides var. ericoides) rises on a single stem from a creeping rhizome. The involucre is narrowly cup-shaped or nearly cylinder-shaped. Flowering time is slightly later, August to October.