Pericarp histology in the Archontophoenicinae provides little to characterize the subtribe as a whole, revealing instead two separate trends with parallels in other subtribes of the Areceae. The data support a close relationship among the three genera occurring in New Caledonia: Chambeyronia, Actinokentia, and Kentiopsis, in which there is a complex endocarp consisting of short, oblique fibrous bundles embedded in a thick mantle of brachysclereids, and a loose endocarp of heavily fibrous, flattened vascular bundles adjacent to a relatively thin locular epidermis. The data also support a close relationship between the two genera of the New Zealand/Tasman Sea region: Hedyscepe and Rhopalostylis, in which the pericarp is more or less fibrous throughout, with purely fibrous bundles in the outer pericarp and heavily fibrous vascular bundles in the inner pericarp. These results confirm relationships revealed by other morphological data. Archontophoenix appears to be most like the New Caledonian genera in its pericarp structure, with a similar mantle of short fibrous bundles embedded in a a mantle of brachysclereids in the outer pericarp, although it differs significantly in other aspects of morphology and anatomy.

Marina victoriae and M. brevis are newly described species from the southern Baja California peninsula, Mexico. The former is a perennial herb locally abundant in the eroded hillsides at the foothills of Sierra de la Victoria, where an oak woodland and a dry tropical forest meet. The latter is an elusive ephemeral inhabiting a narrow strip of land between the mangroves and the desert scrub on an island in the Gulf of California. These two new species belong to the series Chrysorrhizae, a group native to the Gulf of California basin.

Subtribe Oncospermatinae (Arecaceae: Arecoideae: Areceae) is a diverse group of spiny Old World palms. The subtribe includes Oncosperma, a widespread Asian genus of five species, along with seven monotypic genera, all endemic to the Seychelles and Mascarene Islands of the western Indian Ocean. A phylogenetic analysis was conducted in order to test the monophyly of subtribe Oncospermatinae with respect to other Old World genera of tribe Areceae. A matrix of 38 morphological characters was scored for 29 taxa, including 11 species of the Oncospermatinae. A single most parsimonious tree was found, resolving the subtribe as a polyphyletic group of two distinct clades. One clade containing Acanthophoenix, Deckenia, Oncosperma, and Tectiphiala was placed as sister to a large group that includes members of subtribes Archontophoenicinae, Arecinae, Iguanurinae, and Ptychospermatinae. The other clade of Oncospermatinae, including the Seychelles endemic genera Nephrosperma, Phoenicophorium, Roscheria, and Verschaffeltia, was resolved as sister to the Madagascar endemic subtribe Masoalinae, and may have arisen in the western Indian Ocean region.

In a survey of the genus Hybanthus in Brazil, it was found that Ionidium nanum A. St.-Hil. should be considered distinct from Hybanthus albus (A. St.-Hil.) Baill., based on characteristics of indument, habit and nectariferous appendages, and also habitat and geographical distribution. A new combination of I. nanum within Hybanthus is therefore proposed.

Plinia complanata and Plinia pauciflora, two new species from coastal forests of São Paulo state, southeastern Brazil, are described and illustrated.

Bletia purpurea is the most widespread species in its genus. Morphological variation has been recognized throughout the range of its distribution. In this paper, the morphological variation from 63 populations (583 individuals) of Bletia purpurea is assessed to determine whether more than one species were present. Forty-four quantitative and qualitative characters were examined by univariate analyses and exploratory multivariate analyses. Univariate analyses indicate that quantitative characters such as lateral sepal width, petal width, lip length, and lip width are significantly different for populations from Acazónica, Mexico. Floral parts in the populations from Acazónica are the smallest among all populations. Qualitative characters such as petals covering the lip midlobe and horizontal lip position are found exclusively in the same populations. We concluded that these populations should be described as a new species, B. riparia. Multivariate analyses indicated that morphological variation among the other populations cannot be ascribed to geographic distribution or ecological factors.

The present paper describes and illustrates the new species Averrhoidium dalyi and provides a key to the species of Averrhoidium. The new species is known from lowland, terra firme forest in the Purus River basin, in Acre, Brazil, and from Manu National Park in Madre de Dios, Peru.

Dahlia spectabilis (Asteraceae, Coreopsideae), a new species from San Luis Potosí, Mexico, is described and illustrated. The plant is distinguished by its large habit, big flowering heads, and overall lack of trichomes. It occurs within the natural range for the genus and is known from only one location where it is under heavy grazing pressure.

Trilepis tenuis is described from the state of Rio de Janeiro, southeastern Brazil. It differs from the other four species of Trilepis in its delicate habit and combined features of the contraligules and fructifications.

Five new species of Hypolytrum Rich. from South America are described and illustrated. Hypolytrum amorimii and H. jardimii, both of sect. Bullata T. Koyama, are species with pseudopetioles and colored leaves, and endemic to the rain forest of southeastern Brazil. Hypolytrum bahiense (sect. Hypolytrum), a species with a lax synflorescence and two, free and lightly scabridulous floral bracts, is endemic to the rain forest of southeastern Bahia, Brazil. Hypolytrum leptocalamum (sect. Hypolytrum), a species with lax synflorescence and spike ellipsoid to cylindrical, is restricted to area of tepuis in the Guayana Highland (Brazil, Guyana, and Venezuela). Hypolytrum paraense (sect. Hypolytrum), a species with three, partly connate and densely scabridulous floral bracts, is restricted to the rain forest of the Amazon Basin, in the state of Pará, Brazil.

Annona prevostiae, a new species from the northeastern margin of the Guayana Shield, is described and illustrated.