THE DIVERSITY OF MICROMORPHOLOGICAL FEATURES IN THE GENUS COCCOLOBA (POLYGONACEAE)

Coccoloba P. Browne ex is a large and taxonomically complex genus of woody neotropical Polygonaceae. In this study, which includes 70 taxa, leaf and perianth epiderms and pollen surfaces were studied by scanning electron microscopy (SEM). Stomata, primary sculpture, epicuticular wax deposits, and multicellular glandular hairs of leaf blades together with secondary sculpture of perianth epiderms constitute taxonomically important micromorphological characters. Pollen morphology of the examined species is relatively uniform. Types based on surface ornamentation vary continuously from finely punctate‐striate to deeply punctate‐striate or microreticulate. Two species, C. acapulcensis and C. cordata, differ markedly from the rest of the investigated species by having spinulose ektexines. The diagnostic‐descriptive value of the characters studied is more pronounced than the taxonomic‐phylogenetic value. The disjunct distributions of two closely related species pairs C. acapulcencis/C. cordata and C. brasiliensis/C. schomburgkii are discussed. Copyright © 1990, Wiley Blackwell. All rights reserved