Ornamentation pattern of the upper anthecium in Urochloa and related genera (Poaceae, Panicoideae, Paniceae)

Abstract

The ornamentation pattern of the upper anthecium in species of Paniceae belonging to the PCK group, in particular of the genus Urochlo, was analyze. Nineteen different ornamentation patterns were recognized, of which 11 are reported for the first time. Several epidermal elements are described, including simple papillae, compound papillae and ridges in the anticlinal or periclinal cell walls. The ornamentation patterns were useful for infrageneric delimitation in the genus Urochloa but not to delimit the genus from related ones; on the contrary, this character provided more evidence to sustain the paraphyly of the genus. Systematic and phylogenetic value of this character in Urochlo and other related genera are also discussed.