Glabrous, perennial herb, forming very loose mats; stems numerous, freely rooting at nodes, decumbent with ± erect apical parts to c. 7 cm high. Lvs alternate, sessile, densely crowded and imbricate in a cone-like cluster occupying the terminal 2-3 cm of stem, c. 10-25 × 1.2-2.5 mm, c. 1 mm thick, linear or narrowly linear-lanceolate, with lower surface convex and upper surface flat, with angular, entire margins, green or possibly sometimes glaucous-white; apex obtuse or acute. Infl. terminal, usually 8-22 cm high, with numerous, long, leaflike bracts along main rachis; cyme corymbose, usually 2.5-6 cm across, with 2-5 forked branches. Fls numerous, ± subsessile, secund. Sepals ± equal, 2-3 mm long, triangular or triangular-ovate. Petals 5, ± patent, c. 4-5 × 1-1.5 mm, elliptic-lanceolate to elliptic-ovate, yellow, subacute. Stamens 2.5-3.5 mm long; filaments yellow; anthers yellowish. Carpels and styles ± yellow. Scales ± rectangular-oblong, longer than wide. Follicles yellow, ± parallel. Seed c. 0.7 mm long, ellipsoid, papillate but not longitudinally ribbed.