Data from: Piper globirhachis, a segregate species across the Marañon River Valley and the resurrection of Pleiostachyopiper Trel. as a distinct subgenus of neotropical Piper

Piper globirhachis, a new species from northwestern Amazon, is described
and illustrated. It occurs across the Marañon River Valley from its close
relative P. nudilimbum C. DC. with which it has been confounded for ca.
100 years. Piper globirhachis differs morphologically from P. nudilimbum
in having ovate to long–ovate leaf blades, and globose inflorescences, vs.
elliptic leaves, and elongate inflorescences in P. nudilimbum. These
species also differ in geographic distribution and ecological niche. A
molecular phylogeny based on 135 ITS sequences (125 from Neotropical Piper
species and 5 Asian Piper species) enabled the species boundary test
(Poisson-tree-processes, PTP) corroborating that these are distinct
species. Furthermore, these two species formed a well-supported clade
sister to subgenus Oxodium (=Schilleria). This phylogeny highlights the
importance of allopatric speciation in Piper and provides evidence for the
resurrection of Pleiostachyopiper as a subgenus of Neotropical Piper. An
identification key for the subgenera of Neotropical Piper is provided