Ontogeny and diversity in staminate flowers of Nothofagus (nothofagaceae)

Abstract

In Nothofagus, the staminate inflorescences occur in the proximal leaf axils of proleptic seasonal growth units. The subgenera Brassospora, Fuscospora, and Nothofagus have either dichasia of three flowers or a single flower; subgenus Lophozonia has only solitary flowers. Flowers of Lophozonia differ significantly from those of the other subgenera. They have substantially more perianth lobes and stamens, stamen initiation follows a pseudocentrifugal pattern, and the floral meristem is distinctly oval in shape. The solitary 'flower' of Lophozonia is interpreted as a complex structure: a 'pseudanthium' formed by the failure to ramify of a three-flowered dichasium. Pseudanthium development is a ..