Update on the systematics of Benstonea (Pandanaceae): When a visionary taxonomist foresees phylogenetic relationships

The paleotropical monocot Pandanaceae family comprises c. 700 species distributed into five genera: Benstonea (c. 60 spp.), Freycinetia (c. 250 spp.), Martellidendron (6 spp.), Pandanus (c. 450 spp.) and Sararanga (2 spp.). Benstonea was circumscribed to include species previously placed in Pandanus section Acrostigma (one of the four sections of Pandanus subgenus Acrostigma). New phylogenetic data show that the six species of the remaining three sections of subgenus Acrostigma (sections Epiphytica, Fusiforma and Platystigma) and a seventh species doubtfully placed in section Acrostigma (Pandanus microglottis) also belonged to Benstonea. This genus is therefore characterized by a suite of morphological characters, viz. stigmatic groove on the adaxial side of the stigma and a staminate flower reduced to 1 to 3 free stamens (sometimes joined at base). We therefore make here the necessary seven new combinations accompanied by one lectotypification in Benstonea, a genus that now reflects the view of the visionary Benjamin Stone who had already grouped these species in Pandanus subgenus Acrostigma based solely on morphology.