Internodal Meristems of Monocotyledons: Further Studies and a General Taxonomic Summary

The occurrence of uninterrupted (UM) and intercalary (IM) meristemsin the internodes of vegetative and/ or reproductive axes isreported for 90 species in 34 familie of monocotyledons. Meristemtype was determined by measuring regions of surface elongationand cell division in developing internodes. Many aquatic andpredominantly tropical families are included. These new dataand previously published information are presented in a summaryof 45 families in 19 orders of monocotyledons (sensu Takhtajan,1969). The distribution of UM's and IM's is about equal amongfamilies and orders. Phylogenetic trends are not apparent inthe distribution. Generally, UM's tend to predominate in vegetativeinternodes, and IM's tend to predominate in reproductive internodes.