Herbs, epiphytic, without evident stems. Leaves many-ranked, rosulate; blade linear to triangular, base usually with chalklike bloom, margins entire, appressed-scaly. Inflorescence central, 5--many-flowered, always many-ranked, simple or compound, flowers laxly arranged; floral bracts small, inconspicuous, not obscuring rachis. Flowers bisexual in flora or functionally unisexual; sepals distinct, strongly asymmetric; petals distinct; stamens included, usually in 2 unequal sets, filaments free; ovary superior. Capsules ovoid to ellipsoid, dehiscent. Seeds with light tan to brown, apical, plumose appendage.