Annual or biennial herb with a slender taproot to 15 cm tall Stem: low, diffusely forked, spreading, sometimes minutely hairy. Leaves: opposite, fused at the base, stalkless, 0.5 - 2.5 cm long, linear, one-veined. Inflorescence: a terminal and axillary, compact cluster (cyme) of flowers, subtended by paired bracts. Flowers: without petals, stalkless to nearly stalkless, hypanthium (a floral tube formed by the sepals and stamens) pitcher-shaped, abruptly expanded above. Stamens usually five to ten. Styles two. Sepals: five, distinct, greenish, equaling or longer than the hypanthium, lance-shaped with a more or less pointed tip, narrowly scarious-margined (dry, thin, and membranous) near the tip. Fruit: bladder-like, one-seeded (utricle), indehiscent, egg-shaped, enclosed in the persistent hypanthium. Seed yellowish, rounded.
Similar species: No information at this time.
Flowering: April to late November
Habitat and ecology: Introduced from Asia. An occasional weed of sandy, disturbed areas such as lawns, vacant lots, and nursery plots.
Occurence in the Chicago region: non-native
Etymology: Scleranthus comes from the Greek words skleros, meaning hard, and anthos, meaning flower, referring to the hardened flowers. Annuus means annual.
Low, diffuse, spreading, glabrous or puberulent annual or biennial to 15 cm; lvs linear, the larger ones 5-25 mm; fls sessile or subsessile; sep equaling or longer than the hypanthium, lanceolate, ±acute, with a very narrow scarious border (ca 0.1 mm wide) near the tip; stamens usually 5-10; 2n=22, 44. A weed in fields, roadsides, and waste places; native of Eurasia, established in our range from Que. to Wis., s. to S.C. and Mo. All summer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.