Neotropical Costus species may be divided into four artificial (morphological) groupings for ease in identification. Some species have bracts with leafy appendages, or the bracts curve outwards to give that appearance. Other species, the bracts are non-appendaged and the inflorescence forms a tight cone.
The general shape of the flowers is another character that can be used to group neotropical Costus species. In some species the labellums close around the stamens to produce a tubular type flower. Others produce flowers with a more open labellum. The boundaries between these four artificial groupings are not always hard and fast but can provide a very useful start in identifying a species. The thumbnails below are divided between these four groups:
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