Phylogenetics of the Antillean Goetzeoideae (Solanaceae) and Their Relationships within the Solanaceae based on Chloroplast and ITS DNA Sequence Data

Coeloneurum, Espadaea, Henoonia, and Goetzea are shrubs and trees that are endemic to the islands of Cuba, Hispaniola, and Puerto Rico in the Greater Antilles. A phylogenetic analysis was conducted to elucidate the evolutionary relationships among them and with other major lineages of the Solanaceae. DNA sequences of the chloroplast genes ndhF, rbcL, and trnL-trnF intron and intergenic spacer were obtained for twenty two taxa and sequences of the nuclear rDNA ITS region were obtained for eight taxa comprising a data set of over 5,000 bp. The inferred phylogeny groups the Antillean genera together with the South American Metternichia and Duckeodendron in a clade within the Solanaceae, pointing to a broader circumscription of the Goetzeoideae. Both chloroplast and nuclear datasets find the following relationships among the Antillean taxa: (Coeloneurum (Henoonia (Espadaea, Goetzea))). The South American genera Metternichia and Duckeodendron are the first and second sister groups, respectively, to the Antillean genera. The close relationship of Metternichia to the Antillean genera also is supported by pollen morphology. Phylogenetic inference suggests that the Antillean taxa first occuppied xeric environments and evolved into more mesic habitats. Floral characteristics indicate evolution of pollination systems from nocturnal, insect-pollination in Duckeodendron and Metternichia to diurnal, bird-pollination in the Antillean genera. Duckeodendron and the Antillean genera produce drupes, but their contrasting morphology and anatomy suggest that these fruit types originated from separate evolutionary events. Coeloneurum Radlk., Espadaea A. Rich., Goetzea Wydler, and Henoonia Griseb. are tropical plant genera distributed in three of the four islands of the Greater Antilles, the archipelago composed of the islands of Cuba, Hispaniola, Jamaica, and Puerto Rico. The Hispaniolan genus Coeloneurum and the Cuban genera Espadaea and Henoonia are monotypic, whereas Goetzea comprises two species, one endemic to Hispaniola, and the other endemic to Puerto Rico. None of the species in these genera occurs in Jamaica. The systematic placement of these taxa (in this work referred to as ‘‘the Antillean genera’’) has been problematic since the first member of the group was described by Wydler (1830). Wydler initially placed G. elegans in the Ebenaceae. Espadaea was subsequently described by Richard (1850) in the Verbenaceae, and Henoonia was named by Grisebach (1866) in the Sapotaceae. Miers (1869) was the first author to suggest a placement for the Antillean genera in their own tribe or family. Subsequent studies brought these four Antillean genera into or near the Solanaceae. A study by Radlkofer (1888) on the vegetative anatomy of Henoonia found that the presence of crystal sand and intraxylary phloem, and the lack of lactifers suggested that they belong to the Solanaceae. Wettstein (1895) included the Antillean genera in the subtribe Goetzeinae of tribe Cestreae in the Solanaceae. D’Arcy and Keating (1973) studied the leaves of Goetzea and other members of the Solanaceae and argued for the validity of the Goetzeaceae. A study by Gentry (1986) on the pollen morphology of selected genera to elucidate tribal and generic relationships of the Cestreae (sensu Wettstein 1895) found differences between the pollen of Goetzea and Coeloneurum and the other solanaceous genera examined, leading Gentry to conclude that the Antillean genera ‘‘clearly do not belong in the Solanaceae.’’ Further, Hunziker (1979) suggested the validity of the Goetzeaceae as a satellite of the Solanaceae, a hypothesis supported by Carlquist (1988) on the basis of wood anatomy. Studies on the leaf anatomy of the Antillean genera (Zona 1989; Vales and Fuentes 1990) found a set of features that together suggest a strong solanaceous affinity. These are the presence of glandular trichomes and uniseriate trichomes with long terminal cells, sinuous anticlinal epidermal walls, crystal sand and druses, and intrax-