Plants perennial, tufted, pubescent or glabrous. Stems ascending to loosely spreading or prostrate, simple or with few to many lateral branches bearing only tiny, succulent, subulate leaves, not filiform. Leaves: axillary fascicles of subulate, fleshy leaves among distal cauline leaves, giving knotted appearance; basal ascending, forming tuft, not in rosettes, blade linear, ca. 15-30 mm, herbaceous, apex apiculate to mucronate, glabrous or glandular; cauline conspicuously connate basally, cuplike, proximal with blade linear to subulate, apex apiculate to mucronate, glabrous or glandular-pubescent, axillary fascicles of leaves absent; distal with blade subulate, 1-1.5 mm, fleshy, apex mucronate, glabrous. Pedicels filiform, base glabrous or glandular-pubescent. Flowers terminal and axillary, 5-merous or 4- and 5-merous; calyx base glabrous or glandular-pubescent; sepals elliptic, 2-3 mm, hyaline margins rarely purplish, apex frequently purplish, obtuse to rounded, remaining appressed after capsule dehiscence; petals elliptic to orbiculate, 3-4.5 mm, ca. 2 times sepal length; stamens 8 or 10. Capsules 3-4 mm, longer than sepals, dehiscing to base. Seeds dark brown, ovoid to reniform, laterally compressed, 0.5 mm, smooth or distinctly pebbled, abaxial groove present or absent.Subspecies 2 (2 in the flora): North America, Europe.