Studies on Pseudo-terminal Buds of Broad-leaved Tree and Shrub Species in Japan

Abstract

The formation of pseudo-terminal buds as a normal habit was ascertained in 236 spp. among about 700 broad-leaved tree and shrub species common to the japannese flora. The majority of them are with alternate phyllotaxis (89%) and deciduous (94%). The apical parts of the shoots, on which pseudo-erminal buds are formed, are abscised leaving more or less distinct branch scars near the base of the buds in 162 spp.(69%), or aborted leaving shrunk tops or spines in 74 spp.(31%). There is not found any clear correlation between these sorts of these of shoot-top conditions and the taxonomic position of these species. On the other hand, about three fourths of the species with pseudo-terminal buds are those distributed in cooland warm-temperate zones. And these facts may suggest that the formation of pseedoterminal buds is a habit acquired by those species through the process of spreading their distribution to areas of lower temperatures and of changing to deciduousness.