A Synopsis of the genus Habenaria is presented for the New World species in two parts. The taxonomic status, typification, geographical distribution and taxonomic notes are presented for each species. A total of 672 names have been proposed for New World Habenaria, 298 of which are presently accepted. 235 are synonyms in Habenaria and 133 belong in other genera, mostly Platanthera. At least 22 of the accepted species are obscure or poorly understood. 107 lectotypifications, one new combination and 44 new synonyms are proposed. Brazil, with 167 taxa, has most species, followed by Mexico, with 72 species, and Venezuela with 44 species. Brazil (105 spp.) and Mexico (53 spp.) also have the greatest number of endemic species. Other apparent centers of endemism are Bolivia and Costa Rica. 205 species are restricted to a single country, but narrow endemics are few. None of the New World species occurs in other continents. The first part of the synopsis lists species in the range A—L.

Xyris bracteicaulis (Xyridaceae) is described as a new species known only from a single collection from Long Island, New York. The Coastal Plain pondshore habitat in New York supports dynamic plant communities with species rare for the state. The new species is described, illustrated, and compared to morphologically similar specimens.

Sobralia rhizophorae, from the mangroves of Reserva Ecológica Manglares Cayapas-Mataje (REMACAM) in northwestern Ecuador, is described and illustrated. The new species is characterized by stems with a terminal, cone-like inflorescence bearing white flowers, produced singly in succession, and the obovate labellum with five parallel longitudinal keels, a yellowish-brown spot within, and a heavily undulate margin at the distal third.

Field and herbarium studies for a taxonomic revision of Cambessedesia have led to the discovery of two new species, Cambessedesia angelana and C. uncinata. Each of these new species has a restricted distribution in campo rupestre, rocky field habitats above 1200m, of Minas Gerais and Bahia states respectively. These new species are described, illustrated, and compared with their presumed closest relatives.

Two new genera and three new combinations are proposed herein for Neotropical Capparaceae: Caphexandra, a monospecific genus of shrubs or small trees from southern Mexico to Panama, distinguished by the branchlets with subterminal small cataphylls on the raceme axis, calyces with closed aestivation in bud with the outer pair of sepals enclosing the dimorphic inner pair, asymmetric corollas with large unguiculate petals, long (2–5 mm) narrowly-lanceolate floral nectaries, and six stamens arranged in one whorl, which at anthesis forms adaxially an hemiorbicular arc opposite to the gynophore. Caphexandra is represented only by the new combination C. heydeana, a species of horticultural interest herein transferred from Capparis, and Preslianthus, a genus of shrubs or trees from Nicaragua to Brazil, characterized by a stellate pubescence, and flowers with stamens conspicuously accrescent just before anthesis. Preslianthus comprises the following two species, herein proposed as new combinations, also transferred from Capparis: Preslianthus detonsus and Preslianthus pittieri. Capparis schunkei is synonymyzed under P. pittieri. The new genera are illustrated and their relationships discussed.

Between 1881 and 1884, botanical collector Cyrus Guernsey Pringle made almost 2,700 collections of vascular plants in the western United States and Mexico. Of these, about 8%, representing 57 families, were considered new to science. This paper presents 230 taxa for which Pringle's fieldwork supplied nomenclatural types. Questions are identified and discussed regarding both Pringle's collections and the type status of these names. Fifteen lectotypes are designated herein.

Five South-American species of the genus Ocotea from Bahia, Brazil, are described and illustrated. The new species are Ocotea adamantina, O. rohweri, O. sperata, O. thinicola, and O. vegrandis. Their relationships within the genus are discussed.

The long-petaled slipper orchid of Central American has a complex nomenclatural history. Since the first publication of the name Cypripedium humboldtii, this plant has been treated under a number of different synonyms. Here we reconsider the oldest name, suggesting that Warszewicz validly published it, and that the name Phragmipedium humboldtii must be used for this taxon.

A new combination is provided for Asplenium ×joellaui as a nomenclatural correction for Asplenium ×laui (2011), the later being a later homonym of A. laui (1964).

Myrciaria racemosa, a new species of Myrtaceae from Ecuador, is described and illustrated, with notes on distribution and phenology.