Chromosomes of Tuxtla pittieri (Asteraceae; Heliantheae)

Abstract

Tuxtla pittieri (Asteraceae; Heliantheae), which was recently described as the only species of a new genus from Costa Rica and Mexico, is found to have 2n=34 (x=17) and interphase nucleus of diffuse-complex chromocenter type. Of 34 metaphase chromosomes, 30 have centromeres at median position, two at submedian position, and two at terminal-subterminal position. Shared basic chromosome number x=17 suggests close relationships of Tuxtla to Verbesina.