Comprehensive DescriptionRead full entry
DescriptionAnnual or perennial herbs, usually with short stems. Leaves narrow, spirally arranged in a crowded basal rosette (rarely (setaceum) borne on elongated stems). Inflorescence capitate, white, dirty grey, brown or black. Capitula of many small unisexual flowers on a central receptacle, surrounded by 1-several whorls of involucral bracts; each flower often subtended by a floral bract. Flowers (2-)3-merous, ± actinomorphic to strongly zygomorphic. Perianth usually composed of 2 distinct whorls; calyx of free to almost connate sepals, sometimes spathe-like especially in male flowers. Petals free or partly connate, often with a subapical black gland. Male flowers: stamens as many as or twice the number of sepals. Female flowers: ovary 2-3-locular, superior; style branched. Fruit a loculicidally dehiscent capsule; each loculus 1-seeded.