Taraxacum mirabile, an enigmatic sexual halophilous endemic dandelion, represents a new section

Abstract

Taraxacum mirabile Wagenitz (Asteraceae, Cichorieae, Crepidinae), a remarkable but taxonomically unexplored endemic species of Central Anatolia, is examined in detail. It is shown to be a sexually reproducing diploid (2n=16) species. It used to be included in Taraxacum sect. Orientalia in the literature. However, the nrDNA analysis revealed that T. mirabile is remote from that section. Moreover, it exhibits a munber of unique features, such as fleshy leaves with a white, cartilaginous apex, long, dense, bright white tomentum at the plant base, multiple root heads, achenes with an extremely short conical cone and with very few minute spinules, a very narrow involucre with imbricate outer phyllaries, and white, not numerous florets. The most specific feature of T. mirabile is the fine, microscopic sculpture of achene surface, consisting of hair-like protuberances, not known in other Taraxacum species. These attributes, together with the convincing result of the nrDNA analysis, qualify T. mirabile to be recognized as a member of a separate section, T. sect. Echinulata, sect nov. The habitat and distribution of T. mirabile are described, and the character of its endemism is discussed.