Inflorescence Position as a Taxonomic Character in the Cyclanthaceae

Abstract

Studies of 47-49 species of Cyclanthaceae indicate that inflorescence position and shoot morphology are taxonomic characters that aid in identifying specimens within the family, both in the field and laboratory. In all studied species of Carludovica, Cyclanthus, and Evodianthus, inflorescences are terminal, and individual rhizomes are composed of renewal shoots, whereas in Asplundia, Dicranopygium, Ludovia, Schultesiophytum, Sphaeradenia, Stelestylis, and Thoracocarpus, only axillary inflorescences and rhizomes lacking renewal shoots are known. Axillary inflorescences exhibit a prophyll (adaxially situated, bicarinate scale leaf) basally on the peduncle. In species with terminal inflorescences, prophylls form on rhizomes. In certain species of six genera, inflorescences may form a cluster axillary to a rhizome-borne leaf. The commonality and broad taxonomic distribution of axillary inflorescence clusters among extant Cyclanthaceae indicate that they represent a primitive feature within the family.