Lakeside Daisy
Tetraneuris herbacea
Aster family (Asteraceae)

Description: This perennial wildflower consists of a rosette, or clustered rosettes, of basal leaves from which one or more flowering stalks develop. The ascending to spreading basal leaves are 1-6" long and 1/8–1/2" (3-12 mm.) across; they are dark green, linear-oblanceolate in shape, smooth along their margins, and mostly hairless. The leaves of plants that are under stress from drought may become grayish green. Individual flowerheads develop at the apex of unbranched stalks that are 4-12" high; these flowering stalks are more or less erect. The stalks are rather stout and more or less finely pubescent. Individual flowerheads span 1-1" across, consisting of 10-30 ray florets that surround a dense cluster of 50 or more disk florets. The petal-like rays of the ray florets are –" long, bright yellow, oblong in shape, and divided into 3 blunt teeth at their tips. The tiny disk florets are golden yellow, tubular in shape, and lobed along their upper rims. Both ray and disk florets are fertile. Around the base of each flowerhead, there are green floral bracts (phyllaries) in 2-3 series. Individual floral bracts are about " in length, finely pubescent, and oblong-ovate with rounded tips. The blooming period usually occurs from late spring to early summer. A colony of plants may bloom for about a month. The florets are replaced by small achenes that are angular and finely pubescent; they become mature during the summer. At the apex of each achene, there is a tiny crown of 5 or more chaffy scales that are lanceolate in shape. The achenes are distributed by gravity and wind, although they usually don't travel far from the mother plant. The root system consists of a short stout caudex that eventually branches, forming a cluster of plants from vegetative offsets.

Cultivation: The preference is full sun, well-drained mesic to dry conditions, and a gritty alkaline soil containing gravel or rocky material. This wildflower can be cultivated in rock gardens. The seeds require no winter dormancy and should be sowed during the same year that they are produced.

Range & Habitat: Lakeside Daisy is a rare native wildflower in Illinois, having been found in only Tazewell and Will counties (see Distribution Map). It is state-listed as 'endangered' and federally listed as 'threatened.' At one time, this wildflower was extirpated from the wild in Illinois, although it still existed in private gardens in the Chicago area. More recently, it has been successfully reintroduced in various natural areas of the state. The largest population in the United States exists in Marblehead Peninsula along Lake Erie in Ohio. Habitats consist of dry dolomite prairies and gravel prairies, gravelly hill prairies, sand-gravel terraces along major rivers, ledges along cliffs, and limestone quarries. This wildflower is found in rocky areas with sparse vegetation and can tolerate minor amounts of disturbance.

Faunal Associations: Both nectar and pollen are available from the flowerheads, which attract bees, flies, beetles, butterflies, and skippers. Floral bee visitors include bumblebees, small carpenter bees (Ceratina spp.), and Halictid bees. Cross-pollination is required because individual plants are genetically self-incompatible. Insects that feed on the Lakeside Daisy include grasshoppers and the larvae of an unidentified weevil; the latter feeds on the seeds. The flowering stalks are eaten occasionally by the White-Tailed Deer and Cottontail Rabbit. In the Western states, related species in the Hymenoxys/Tetraneuris complex are known to have toxic leaves that can poison cattle and sheep, however the toxicity of the more eastern Lakeside Daisy has not been determined.

Photographic Location: A botanical garden in the Chicago area. The photographs of the Lakeside Daisy were taken by Jim Ault (Copyright 2010).

Comments: The Lakeside Daisy is an attractive plant. This wildflower is rare because of its restrictive habitat requirements and the limited distribution of its seeds. Lakeside Daisy is one of several spring-blooming species in the Aster family that have yellow flowerheads and rosettes of basal leaves. It can be distinguished from these other species by its narrow dark green leaves, unbranched flowering stalks, three-toothed rays, and achenes with tiny crowns of scales (rather than a tufts of hairs). Other closely related species exist in the Western states. The Lakeside Daisy is sometimes classified as var. glabra of the western Hymenoxys acaulis. However, this latter species differs by having fewer ray florets (less than 15), floral bracts (phyllaries) with awned pointed tips, and basal leaves that are gray-green with silky hairs.