Phylogeny and Systematic Position of Feddea (Asteraceae: Feddeeae): a Taxonomically Enigmatic and Critically Endangered Genus Endemic to Cuba

The systematic position of Feddea (Asteraceae) has been enigmatic ever since its publication in 1925. The latest taxonomic accounts of the family left it either unplaced within subfamily Asteroideae or unplaced within tribe Inuleae. Macro-morphological and electron microscopy data (scanning electron microscopy and transmission electron microscopy) indicated that Feddea is not part of an early branching lineage of the Asteraceae, contrary to what had been suggested in initial taxonomic accounts. Feddea has style branches with a 2-banded (vs. continuous) stigmatic surface, thus differing from early diverging lineages of the family. Among Asteroideae, Feddea is diagnosed by discoid capitula with all florets bisexual, long-caudate anthers, noncarbonized cypselae, and pollen with a narrow cavus region, columellae without internal foramina, but with a complex basal columellate layer. A phylogenetic reconstruction based on nucleotide sequences of the chloroplast gene ndhF showed that Feddea is sister to the Heliantheae s.l. There were, however, no clear morphological synapomorphies shared with that tribe and we therefore propose Feddeeae as a new unispecific tribe to accommodate this critically endangered genus restricted to Eastern Cuba.