Structure and systematics of Hanguana, a monocotyledon of uncertain affinity

Floral anatomy and some aspects of leaf and root anatomy of Hanguana are de scribed for the first time and reviewed with respect to its systematic posi tion in monocotyledons. Several characters support its placement in the com melinoid clade, including cell wall ferulates, silica bodies and tetracytic stomata with non-oblique cell divisions. Analysis of morphological data in dicates that Hanguana is the sister taxon to Zingiberales. Characters suppo rting this association include spinulate inaperturate pollen, plasmodial ta petum type, mucilage-secreting intra-ovarian trichomes and modified septal nectaries. Gynoecial nectaries were present in male flowers (probably modif ied septal nectaries, as in some Zingiberales) and staminodial nectaries in female flowers examined.