Bracteole Types

By far the most common type of bracteole in Costus is a single-keeled (unicarinate), "canoe shaped" bracteole (referred to as "boat shaped" in the formal descriptions). However, there are two species (Costus osae and Costus ricus) that always have a two-keeled (bicarinate) bracteole that is shaped more like a flat-bottom boat. There are other species that sometimes have ths two-keeled bracteole, but that is an exception to the norm.