Hieracium

Hieracium is a large and complex genus in the family Compositae; its common name is hawkweed. Plants of this genus are widely distributed in the temperate and subarctic regions of the Northern Hemisphere. An excellent account, including a detailed history concerning the British Hieracia written by Pugsley, was published in 1948 by the Linnean Society of London. ¹⁰ According to Pugsley, ¹⁰ although the name Hieracium was first mentioned in the treatise “De Medica Materia” of Dioscórides, the two species identified were not Hieracia in the modern sense. ¹⁰ The first true Hieracium to be identified appears to have been H. pilosella which was described by Brunfels in 1530 as Pilosella or Auricula Muris. The earliest unmistakable description of todays Hieracia can be found in Ray’s “Historia Plantaram” which was published in 1686. Since that time, many more species have been described. The most notable monograph on the taxonomy of this genus is found in the work of Zahn in which he described 756 species and their subspecies. ¹⁵ This genus is composed of perennial herbs and is well known for its apomictic members and taxonomic complexity. ⁵ This group of plants has a rosette habit of growth in the vegetative phase. Flowers are usually yellow, sometimes red-orange, and occasionally white. Plants of this genus have long been used for the study of apomixis, ⁷ population biology and flowering ecology, ^{2 , 3 , 11-13} and natural product chemistry. ⁴