Comprehensive DescriptionRead full entry
DescriptionThis herbaceous plant is a winter or spring annual, producing leafy and flowering stems about 4-18" (10-45 cm.) long. These stems branch primarily near the base of the plant and they are ascending to widely sprawling. Individual stems are whitish green to light reddish green, terete, and woolly-pubescent. Alternate leaves occur along these stems that are ¾-2" (2-5 cm.) long and about one-half as much across; they are broadly oblong in outline, while their structure is deeply bipinnatifid. The ultimate leaf segments are 1.5-5.0 mm. long and about one-third as much across; these segments are oblong-acute in shape. The leaves are pale green and they are covered with short woolly pubescence that becomes more sparse with age. The short petioles are relatively broad, flattened, and whitish green to nearly white; they usually have simple or pinnate lobes along their margins that resemble the leaf segments. The upper stems terminate in individual flowerheads that span about ¾-1¼" (2-3 cm.) across; these flowerheads have peduncles that are 1½-6" (4-15 cm.) in length. These peduncles are pale green, terete, and woolly-pubescent. Usually, small alternate bracts occur along the peduncles that resemble the leaves. Each daisy-like flowerhead has 10-18 ray florets that surround numerous disk florets; the ray florets are fertile and pistillate, while the disk florets are fertile and perfect. The petaloid rays of the ray florets are white, oblong in shape, and notched at their tips. The tiny corollas of the disk florets are yellow, tubular in shape, and 5-lobed at their apices; these lobes are triangular in shape. Alongside the disk florets, there are chaffy scales about 4 mm. in length. These scales are oblanceolate in shape and their tips are acute; sometimes these tips are awn-like. At the base of each flowerhead, there are 1-2 series of phyllaries (floral bracts) that are broadly oblong in shape. Individual phyllaries have convex central ridges that are light green, wide membranous margins that are white to light brown, and woolly pubescence; the phyllaries become chaffy with age. The foliage of this plant lacks a significant fragrance, although the crushed flowerheads are mildly fragrant (resembling apple-pineapple). The flowerheads are solid, lacking hollow centers. The blooming period usually occurs from late spring to mid-summer, lasting about 1-2 months, although some plants may bloom later in the year. At maturity, the seedheads are ovoid in shape. The achenes are 1.5-2.5 mm. in length, oblanceoloid in shape, and slightly 4-angled; they are truncate at their apices, where they lack tufts of hair or significant scales. The sides of mature achenes have longitudinal ribs that are readily visible. The achenes are distributed to a limited extent by wind and probably by water at some locations. The root system consists of a shallow much-branched taproot or it is fibrous. Reproduction is by seeds.