The new name Ouratea cataniapoensis (Ochnaceae) is proposed to replace the illegitimate homonym O. megaphylla. Chorological and taxonomic notes about these taxa also are provided.

Thirty-eight species of the genus Stelis (Orchidaceae) from Colombia, or species that can be expected to be found in Colombia, are described, three as new species (S. dapidis, S. nostalgia, and S. peregrina). Thirty-two species are illustrated, thirteen multiple times. Already existing illustrations are cited for six species. A lectotype is selected for Pleurothallis pristis and a neotype for S. guatemalensis.

The 90 new combinations on Neotropical Capparaceae published in The Global Flora (Plant Gateway, 2018) are here discussed and clarified. On the basis of morphologic and molecular studies, the name of Morisonia L. cannot be applied in a broad sense for all Neotropical Capparaceae. Therefore, the names proposed by Christenhusz and Byng are placed in synonymy here.

An amended authorship and lectotypification are proposed for Gustavia pubescens (Lecythidaceae), a treelet endemic to western Ecuador, and its IUCN conservation criteria are assessed.

We present here a taxonomic synopsis of the native representatives of the family Acanthaceae in Paraíba State, northeastern Brazil. Fertile material was collected during monthly excursions between November 2014 and November 2015. We also analyzed specimens deposited in the Lauro Pires Xavier (JPB) and the Jayme Coelho de Moraes (EAN) herbaria, as well as consulted the REFLORA—Virtual Herbarium of the Flora and Fungi from Brazil and the Species Link databank. Taxonomic identifications were based on morphological analyses and consulting the literature. A total of 24 species belonging to 10 native genera were encountered, 11 species being reported for the first time for Paraíba State in this work. The most representative genera were Ruellia L. (8 spp.), Justicia L. (6 spp.), Harpochilus Nees (2 spp.), and Hygrophila R. Br. (2 spp.); the other genera were represented each by a single species. A key to the species, illustrations, and data concerning their geographic distributions, flowering, and fruiting are included. Additionally, a lectotype is designated for Beloperone thunbergioides and a neotype for Hygrophila costata and Justicia imbricata.

Four new combinations in Euploca from South America (Heliotropiaceae), all them endemic to Peru, are proposed in this paper: Euploca lobbii, Euploca oxyloba, Euploca polyanthella, and Euploca toratensis.

Macaranga stolonifera sp. nov. is a taxonomic oddity instantly distinguished by its diminutive stature, monocaulous architecture, and stoloniferous habit. In marked contrast to other Papuasian congeners, the new species is found only in dark understories of mature growth forest. This latest addition to the euphorbiaceous flora of New Guinea is described and diagnostically depicted with in situ photos.

Eugenia walkerae, a new species from the island of Anguilla, is described and illustrated. This species is known only from five herbarium collections, and additional fieldwork is needed to determine its current conservation status. It resembles the Puerto Rican endemic E. woodburyana, and its seeds are comparable to those described for certain species of Eugenia from southern Africa. This is the second species of seed plant currently recognized as endemic to Anguilla.

Literature and herbarium studies of the Neotropical orchid genus Fernandezia Ruiz & Pav. reveal that a number of previously recognized taxa should be synonymized, while at the same time it is necessary to propose several new taxa (45 species and 11 varieties). Fernandezia distichoides (Pachyphyllum distichum) and F. pectinata are lectotypified, and F. vaginata is neotypified. An infrageneric subdivision is proposed for Fernandezia, in which six sections are recognized. Section Capitata is transferred from Pachyphyllum, Orchidotypus is reduced to sectional level (as it was in Pachyphyllum), and three new sections are proposed, namely, section Breviconnata, section Gracillima, and section Lamellata.

Notes are supplied on various species of the Jewel Orchid genus Zeuxine, particularly those taxa found in western Malesia, nearby Thailand, and Cambodia. Narrower circumscriptions are proposed for Z. gracilis and Z. parvifolia, whereas Z. flava is expanded into a broader concept. Zeuxine leucochila is reinstated, and the identities of Z. exilis and Z. rupestris are clarified. Zeuxine leucochila var. cambodiana is raised to species status as Z. cambodiana, and three new species are proposed, namely, Z. eryliae, Z. pseudogracilis, and Z. subquadrata.

A reinstatement, three new combinations, and one new species are proposed for orchids that occur in India and Sri Lanka. The name that is reinstated is Dendrobium crispum, with D. peguanum treated as a synonym; the new combinations are Cylindrolobus lindleyi, Peristylus caranjensis, and Trichotosia thwaitesii; and Dendrobium turbinatum is proposed as a new species.

The species traditionally included under the synonymy of Trichocentrum albococcineum are re-evaluated, and T. orthoplectron is reinstated as a separate species. A new species of Trichocentrum from Bolivia, T. moreniorum, is described and illustrated, and its relationships with other species of the genus are discussed. A key to the species of the Trichocentrum fuscum group is presented.

This work presents 11 new records for species of Malvoideae (Malvaceae) found in Paraíba state, northeastern Brazil: Herissantia crispa, Malachra fasciata, Malvastrum coromandelianum, Pavonia malacophylla, Sida acuta, S. castanocarpa, S. glaziovii, S. glomerata, S. jussiaeana, S. urens, and Sidastrum micranthum. Data on geographical distribution, habitats, flowering, and fructification and notes about morphological characters are presented for the species

The most recent phylogenetic analyses using molecular and morphological data of Hechtioideae revealed the presence of three well-supported, morphologically distinct clades related to each other as follows: (Hechtia tillandsioides complex [Hechtia guatemalensis complex (Hechtia s.s.)]). (1) H. tillandsioides complex is recognized here at the generic level (under the reestablished name Bakerantha), characterized by its grass-like leaves, which are almost entire or minutely dentate, central inflorescences with pedicellate flowers, and papyraceous, pendent fruits; this clade includes four species confined to the Veracruzan, Sierra Madre Oriental, Balsas Basin, and Transmexican Volcanic Belt biotic provinces. (2) The H. guatemalensis complex, here proposed as the new genus Mesoamerantha, is characterized by the presence of central inflorescences and flowers with ¾ superior ovaries and is confined to the Pacific Lowlands, Veracruzan, Mosquito, and Chiapas Highlands provinces (in Belize, Guatemala, Honduras, El Salvador, and Nicaragua). The remaining sampled taxa are grouped into a clade (3) that consists of three well-supported lineages: the Hechtia glomerata complex distributed in the drainage of the Gulf of Mexico; a clade conformed by two species (H. deceptrix and H. epigyna) from the Sierra Madre Oriental that share an inferior ovary, and a poorly resolved internal clade (Core Hechtia) with the remaining species containing several well-supported, geographically restricted clades.

Four new species of Meconopsis—M. huanglongensis, M. inaperta, M. hispida, and M. trichogyna—are described and illustrated, M. barbiseta is redescribed, and a new series of Meconopsis, series Barbisetae, is proposed.

A new species, Knoxia hookeri (Rubiaceae), is proposed here, and a discussion about the invalidity of the three previously published names is presented. A dichotomous key is provided to distinguish the two Knoxia species: K. hookeri from K. sumatrensis. The synonymy of both species is presented with comments on typification.

The background and accomplishments of Darwin's work on Catasetinae are analyzed, and issues that he and others did not resolve are discussed in detail. The segments on Catasetinae published by Darwin in the Annals and Magazine of Natural History in September 1869 and in the second edition of his orchid pollination opus (as Catasetidæ) published in 1877, as well as his paper “On the three remarkable sexual forms of Cataseum tridentatum,” all including the text, plates, and notes, are presented in three appendixes.