Coarse to low and moss-like, perennial or annual, caulescent to acaulescent rosulate herbs with fibrous roots and perennating by rhizomes or axillary buds. Principal foliage leaves with broadly clasping sheaths, blades linear-triangular to linear, flat to thickened, angled or lingulate, the tip frequently excentrically or symmetrically aristate or conic-subulate. Inflorescences consisting of a single sessile flower or a 2-or more-flowered spike, this sessile or more often terminal on a scape (rarely a terminal cluster), usually with 1 or more pairs of subopposite, sessile, erect, bract-like leaves; bracts paired at spike base, spirally arranged upward, or all spirally set, all fertile or the lowermost sterile, mostly glumaceous, usually rigid, lanciform-navicular with a thickened dorsal area and broad, mostly entire, scarious margins, frequently apically produced to a stiff mucro, cusp or seta. Sepals 2-3, the laterals often similar to bracts but thinner with narrow, thickened, curvate-keeled (at least apically) back, subopposite, the third (inner) sepal reduced or lacking; corolla salverform, tube variously elongate, lobes equal, broad, blue to white or violet; stamens 3, filaments adnate near base of petal blades, shorter or longer than anthers, flat or terete, anthers mostly narrow, with locule bases variously divergent on a broadened, flattened connective; staminodes 0-3; ovary trilocular, placentation axile, ovules numerous, style typically elongate, bearing 2-3 usually pendent, less often ascending, claviform (to filamentous, rarely bifid) appendages at or near base, apically with 3, usually distally dilated and flattened stigma branches, these variously divided or connivent, mostly lacero-fimbriate. Capsule with 3 valves firm and mostly much thickened at the crested, lobed, or toothed, smooth to papillose apex; seeds mostly tumid and irregularly obovoid, 0.5-1 mm long, short-apiculate or umbilicate, the broad body dark, spirally-longitudinally coarsely ribbed, frequently with strong, irregular cross-ridges