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DICHOTOMOUS BRANCHING IN MAMMILLARIA (CACTACEAE)
Author(s) -
Boke Norman H.
Publication year - 1976
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1976.tb13223.x
Subject(s) - biology , phyllotaxis , botany , branching (polymer chemistry) , genus , shoot , meristem , composite material , materials science
Cruciate dichotomous branching is a regular phenomenon in at least two species of cacti: Mammillaria perbella and M. parkinsonii , and there is exomorphic evidence that it occurs in other species of this genus. The specimens examined showed no obvious changes in the phyllotaxy of the two shanks derived by dichotomy. In the ecologically and morphologically specialized Cactaceae, it is quite unlikely that dichotomous branching represents the retention of a primitive character. It is furthermore improbable that it is of taxonomic value above the species level.