Cichorioideae

Cichorioideae is a subfamily of the Asteraceae (the sunflower family). It comprises a diverse group of mostly herbaceous plants, many of which produce a milky latex. A defining feature of many genera in this subfamily is the capitulum (flower head) composed exclusively of ligulate, or strap-shaped, florets, rather than the mixed heads seen in other Asteraceae. The pappus is often absent or reduced in this group.

The subfamily includes several well-known genera, such as Taraxacum (dandelions), Cichorium (chicory), Lactuca (lettuce), Sonchus (sow thistles), and Hieracium (hawkweeds). These plants range from common weeds to agricultural crops and garden ornamentals. They are found in a variety of habitats, with a strong presence in temperate regions, though some species extend into subtropical zones.

Taxonomically, Cichorioideae has been treated historically as a separate family (Cichoriaceae), but modern classifications place it as a subfamily within Asteraceae. Within the subfamily, the tribe Cichorieae contains many of the familiar ligulate genera and is a major line of the group. Molecular phylogenetic studies have supported the monophyly of Cichorioideae and clarified relationships among its tribes, integrating traditional morphology with DNA data.

Economically and ecologically, members of Cichorioideae are important as crops (lettuce and chicory), foraged greens, and often as pioneer weeds in disturbed habitats. Their characteristic ligulate florets and milky sap remain key diagnostic traits for identification.