POLYCTENIUM Greene, Leafl. Bot. Observ. Crit. 2: 219. 1912.
Ihsan A. Al-Shehbaz
Tribe: Boechereae Al-Shehbaz, Beilstein & E. A. Kellogg, Pl. Syst. Evol. 259: 111. 2006.
Name derivation: Greek poly, many or numerous, and ctenos, comb, in reference to the many comb-like leaves]
Type species: Polyctenium fremontii (S. Watson) Greene (based on Smelowskia fremontii S. Watson).
Herbs, perennial, cespitose, sometimes apically glaucous, pubescent at least basally. Trichomes dendritic mixed with fewer 2-rayed and larger simple ones. Multicellular glands absent. Stems erect to ascending, pubescent. Leaves cauline, lower ones short-petiolate, rigid, pectinate, with linear segments; uppermost leaves similar, subsessile, not auriculate at base. Racemes several-flowered, ebracteate, corymbose, congested or elongated in fruit; rachis straight; fruiting pedicels slender, divaricate-ascending, persistent. Sepals oblong-ovate, free, caducous, erect or slightly ascending, glabrous or pubescent, equal, base of lateral pair not saccate. Petals white or purplish, erect, longer than sepals; blade obovate to oblanceolate, obtuse at apex; claw undifferentiated from blade, glabrous, unappendaged, entire. Stamens 6, nearly included, slightly tetradynamous; filaments wingless, unappendaged, glabrous, free, not dilated at base; anthers ovate, obtuse at apex. Nectar glands confluent, subtending bases of all filament, median glands present. Ovules 30–46 per ovary, placentation parietal. Fruits dehiscent siliques or silicles, linear to oblong or rarely ovate-oblong, slightly to strongly angustiseptate, not inflated, unsegmented; valves papery, not veined, glabrous or sparsely puberulent, not keeled, not torulose, wingless, unappendaged; replum rounded, visible; septum complete, membranous, not veined; style distinct but short, persistent; stigma capitate, entire, unappendaged. Seeds uniseriate, wingless, oblong, plump; seed coat not mucilaginous when wetted; cotyledons incumbent.
Monospecific: W United States.
References: Rollins (1938a, 1983b).