Annual herb with a thread-like to slender taproot 5 - 30 cm tall Stem: upright, forking, much-branched, minutely hairy (mostly on one side). Leaves: opposite, 0.5 - 2.5 cm long, 0.5 - 7 mm wide, reverse lance-shaped to elliptic with a blunt to pointed tip, one-veined, often dotted or blotched, sometimes leathery, sometimes having hair-like growths along the midrib, with conspicuous stipules. Stipules two per node, 0.5 - 4.5 mm long, awl-shaped to lance-shaped with a long-pointed tip, papery. Inflorescence: a terminal, forked, loose to compact cluster (cyme) of 25 to 70 flowers, 3 - 10 mm wide. Flowers: without petals, tiny, hypanthium (a floral tube formed by the sepals and stamens) cup-shaped, sometimes with a few scattered hairs, subtended by stipular bracts that are equal to or longer than the calyx (the sepals, collectively). Stamens usually five. Styles two, short. Sepals: five, ascending or slightly descending, fused at the base, greenish to brownish with white or translucent margins, lance-shaped to linear with a point at the tip, without veins, leathery to rigid, scarious-margined (dry, thin, and membranous), with a prominent, narrowly rounded hood at the end. Calyx (the sepals, collectively) 2 - 3 mm long. Fruit: bladder-like, one-seeded (utricle), indehiscent, about 1 mm long, reverse egg-shaped to reverse conical, membranous, on an upright stalk. Seed brown, laterally compressed.
Similar species: The similar Paronychia canadensis differs by having hairless stems and shorter calyxes (1 - 1.5 mm).
Flowering: June to October
Habitat and ecology: Woods, grassland, and in the shade of picnic areas.
Occurence in the Chicago region: native
Etymology: Paronychia comes from the Greek words para, meaning near, and onyx, meaning nail, referring to the flame colored flowers. Fastigiata means "having close together, erect branches, which often form a column."