The tropical angiosperm order Zingiberales comprises a clade of eight tropical monocot families including approximately 2500 species believed to have undergone an ancient, rapid radiation during the Cretaceous era. Zingiberales show substantial variation in floral morphology, and several members are ecologically and economically important – such as ginger, cardamom, turmeric, galangal, bananas and plantains. Deep phylogenetic relationships among primary lineages of Zingiberales have proved difficult to resolve in previous studies, representing a key region of uncertainty in the monocot tree of life. The Zingiberales comprises a diverse clade of eight families, but deep phylogenetic relationships within them are poorly understood.
A recent paper in Annals of Botany uses next-generation sequencing to generate complete plastid gene sets and finds that plastid genomes provide strong support for many relationships, but only weak support for inclusion of the Heliconiaceae order. Manipulation of various data matrix properties affects tree topology in an unpredictable fashion, suggesting that complete coding regions of the plastome do not provide sufficient character information to resolve this rapid, ancient radiation.
Barrett, C.F., Specht, C.D., Leebens-Mack, J., Stevenson, D.W., Zomlefer, W. B., & Davis, J.I. (2014) Resolving ancient radiations: can complete plastid gene sets elucidate deep relationships among the tropical gingers (Zingiberales)?. Annals of Botany, 113(1), 119-133.