Abstract

AbstractThe cone morphology in Tetraclinis was studied to elucidate the taxonomic position of the genus. A careful analysis of the cone development shows that the characters used as arguments for an affiliation within Callitroideae are superficial and of little taxonomic significance. The developmental patterns indicate a position of Tetraclinis within Cupressoideae. Tetraclinis displays ovules inserted directly at the distal end of the cone axis and not born in the axil of a seed scale as recently shown for Juniperus (Schulz et al. 2003) and Microbiota (Jagel & Stützel 2001b). The close relationship between Tetraclinis, Juniperus and Cupressus as suggested by Saxton (1913) based on embryological data, by Gadek & Quinn (1985) based on biflavones and by Gadek et al. (2000) based on DNS‐sequences is supported by the morphological data presented here. Conflicting morphological concepts or morphological trees (e.g. Gadek et al. 2000) are in parts weakly supported and suffer either from ambiguous coding of morphological data or are based on historical morphological errors. To calculate reliable morphological trees, however, requires data of similar quality and cannot be achieved by using data which are tailed to the use in effective diagnostic keys.

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