short-stemmed epiphytes, sometimes terrestrial. Leaves mostly basal and
rosette-forming, rarely cauline, spirally alternate, often spiny-serrate and
troughlike, sometimes coarsely grasslike or linear to filiform, often brightly
coloured bracts. Flowers bisexual or rarely unisexual. Perianth of 2 series,
outer series of 3 calyxlike, inner series of 3 corollalike, free or connate.
Stamens 6, free or adnate to corolla. Pistil 1, ovary superior to inferior,
3-locular. Fruit a berry or capsule, often
enveloped by the persistent perianth, sometimes syncarpous. Seeds with copious mealy endosperm and small