Regarding the structure and possible function of the columella in seed cones of Callitroideae (Cupressaceae) : a morpho-anatomical approach

Abstract

‘Columella’-named structures in seed cones of callitroid Cupressaceae were investigated. In the past, the term columella was used for different structures, which should not be summarised and treated under the same name. We suggest that all apices should be called columella, which exclusively represent the prolonged tip of the cone axis and do not reach the periphery of the seed cone and do not take part in it. The three distal lobes in Fitzroya Lindl. represent a sterile, strongly reduced, distal whorl of cone scales and not naked nucelli or resin glands as suggested in former studies. They should not be termed columella. The columellae and also the three lobes in Fitzroya may play a role within the pollination process and possibly in the chemical defence against pathogens. The columella, as it is defined here, is not restricted to the Callitroideae and is also present in other Cupressaceae, including Cupressus L. and Thujopsis Siebold & Zucc.