TAXONOMIC SIGNIFICANCE OF CHROMOSOME OBSERVATIONS IN CARIBBEAN SPECIES OF LANTANA (VERBENACEAE)

Chromosome numbers and, in most cases, meiotic configurations are provided for 12 taxa and 5 morphological intermediates of Lantana collected in the Bahamas, Dominican Republic, Florida, the Lesser Antilles, Puerto Rico, and Texas. Reported for the first time are Lantana bahamensis, n = 11; L. microcephala, n = 12; L. leonardiorum, n = 11; L. odorata, n = 12; L. reticulata, n = 24; L. subcordata, n = 11; L. urticifolia, n = 11, 22. Numbers differing from previous reports were obtained for L. involucrata, n = 12, 24, and L. trifolia, n = 27. Triploids indicate the natural occurrence of hybridization between diploid and tetraploid taxa. Bivalents are formed regularly, except in the triploids and in morphologically intermediate tetraploids. These reports confirm that Lantana is based on at least two numbers, x = 11 and 12, and that the genus comprises polyploid complexes in each of these basic lines. The polyploids are weedier and more widely distributed than are the diploids. Chromosome numbers and configurations aid in the delimitation of diploid foundation species and in the recognition of naturalized hybrids.