Penthorum sedoides is a perennial herb, to 70 cm, stems erect, banched above, hairless, sometimes reddish at nodes; colonial from stolons.
Leaves alternate, to 12 cm long, 3.5 cm wide (Yatskievych 2006) narrowly elliptic, pointed at both ends, margin toothed.
Flowers yellow-green, small, usually without petals, sepals 5, 0.1 cm long, persistent in fruit; stamens 10, yellow-pink, longer than pistils, forming a ring around them; pistils (carpels) 5, simple, ovaries fused at base in a ring, styles and stigmas simple, white, forming a ring of beaks in fruit; inflorescence with 5-6 branches, flowers along one side of each branch (secund), stems of inflorescence glandular-hairy (use lens); blooms July-Oct.
Fruit dry 5-horned capsules about 0.6 cm wide, splitting open around the circumference to release numerous small, warty seeds (Radford et al. 1968; Yatskievych 2006).
Wetland status: OBL.
Frequency in NYC: Infrequent.
Habitat: Open, undisturbed wet areas, marshes, pond shores, soil pH 5-7, moderately tolerant of shade, drought, intolerant of salt, anaerobic soil (USDA, NRCS 2006), however I have seen it growing in saturated soil (Gargiullo personal observation; Fern 2004).
Notes: Gleason and Cronquist (1991) put Penthorum in the Saxifragaceae. The USDA, NRCS plants database (2006) puts them in Crassulaceae as does Radford (1968).Cooked leaves apparently edible (Fern 2004).