Taraxacum index

Taraxacum index is an apomictic microspecies within the Taraxacum officinale aggregate, the common dandelion complex, one of many hundreds of narrowly defined microspecies that European taxonomists distinguish within this notoriously polymorphic group. Like other members of the aggregate, it is a perennial herb arising from a long, fleshy, white-fleshed taproot that exudes copious milky latex when cut. The leaves form a flat basal rosette and are oblanceolate in outline, pinnatifid to runcinate with retrorse (backward-pointing) triangular lobes, glabrous and rich green with a paler midrib. A solitary, hollow, leafless scape 10 to 30 cm tall bears a single bright yellow capitulum 2 to 4 cm across composed entirely of ligulate (ray) florets, the outer involucral bracts reflexed in a characteristic dandelion fashion. The mature head produces the familiar globose pappus “clock” of plumed cypselas dispersed by wind. It occurs in meadows, lawns and disturbed grassland habitats within the European range of the aggregate.