Fls sessile or subsessile in the axils of bracts, aggregated into spikes or heads; sep 4, the 2 next the bract often slightly different from the 2 next the axis (sometimes ±connate); cor long-persistent, its tube investing the summit of the fr; capsule circumscissile at or below the middle; ours annual or perennial herbs, most spp. acaulescent.
200+, cosmop.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.