Hedychium J. Koenig (ginger lilies: Zingiberaceae), a genus known for its ornamental value and invasive potential, is undoubtedly a taxonomically challenging genus within Zingiberaceae. Much of the confusion surrounding the taxonomy of Hedychium arises from the introduction of redundant names for the same taxa in various regions of the Indo-Malayan Realm, which has led to a proliferation of synonyms that remain insufficiently explored. Additionally, taxonomic confusion in this genus is also due to the occurrence of numerous natural hybrids and polyploids. In this article, we propose that H. peregrinum N. E. Br. from Madagascar is a synonym of H. roxburghii Blume, and H. sinoaureum Stapf from China is a synonym of H. densiflorum Wall. Additionally, we lectotypify three of these species names. We also identify and characterize two natural hybrid zones of Hedychium from the northeastern states of India. Further, we highlight the importance of naming intermediate taxa or natural hybrids, and propose a curated online repository for Hedychium (including valid species and hybrids), aided by citizen science, which will help us digitally collate information on polymorphism, morphological diversity, and geographic variations within the genus.

Alwyn Gentry’s ecological legacy is rich and vibrant. It comes from his drive to revolutionize plant identification and to apply these innovations to understand tropical forests both in detail and as a whole. It stems too from his passion for plants and forests, and the attention he gave those who shared his love for the natural world. Here I explore the impacts of Gentry’s approach and findings on tropical ecological science today. The big challenges that always face those wanting to understand tropical forests are their high diversity and the fact that most of the time plants here are sterile, while identification depends on reproductive structures. Because flowers are least accessible for the canopy trees and lianas that dominate tropical forests, this affects our ability to measure biodiversity, understand it, and monitor its persistence over time. Gentry has helped to make all these possible. Thanks to his innovations in plant identification and his vision in applying them to whole forests, tropical floristic inventory and ecological monitoring have become almost commonplace and, crucially, replicated across time and space. We now know which forests are most diverse, and why, and how their composition changes over space, climate, and soil. Gentry’s insights and methods help us better understand where conservation needs to focus, how forest people use their environment, and how global changes impact the biodiversity and carbon of Earth’s most complex ecosystems. Finally, his influence includes lasting impacts not simply on what we have learned, but also on how we do our science, and even on who does it.

We compiled a list of the fern and lycophyte species that occur in Mesoamerica and extend into Colombia and Ecuador, where they are restricted to the western side of the Andes; that is, they occur only west of the crest of the easternmost cordillera and are absent from that cordillera’s eastern slope and in adjacent Amazonia. We found 131 species with this Mesoamerican and west-of-the-eastern-cordillera distribution. Those 131 species constitute 7% of the total 1805 fern and lycophyte species that have been recorded west of the crest of the easternmost cordillera in Colombia and Ecuador. All 131 species have elevation ranges with midpoints at low (0–900 m) or middle (900–3000 m) elevations, and none occur above 3000 m. This suggests the cordilleras have acted as elevational barriers. We also investigated the blockage of these 131 species by each of the Andean cordilleras. We found that 75 (57%) of the 131 species were limited eastward by the western cordillera, 15 (11%) by the central cordillera (this cordillera in Colombia only), and 40 (31%) by the eastern cordillera. If estimates of endemics to the western Andean region are considered, then at least 20%–22% of all fern and lycophyte species in the region are restricted west of the crest of the easternmost cordillera. Although usually exhibiting larger geographic distributions compared to angiosperms, fern and lycophyte species may show significant geographic restriction by mountain ranges.

Introduction to the special collection commemorating the life and work of Alwyn Gentry

The Sierra Nevada de Santa Marta (SNSM) is a large, isolated mountain on Colombia’s Caribbean coast. Its isolation has led to high diversity and endemism in its fauna; however, knowledge of the mountain’s floristics remains limited. Here, we aim to better characterize the flora of the SNSM above 1700 m.s.m. Using occurrence records and a literature review, we compile a list of all known seed plants endemic to the SNSM montane flora and perform biogeographical analyses to compare the cloud forest and páramo floras of the SNSM to those of surrounding mountain ranges in the northern Andes and Central America. We first compared broad patterns in collection efforts and species diversity across mountain ranges. We then analyzed the elevational limits of plant species on the SNSM and surrounding mountain ranges to test for the Massenerhebung effect (i.e., the phenomenon that species have higher elevational limits on large mountains rather than small mountains). Finally, we performed a cluster analysis to explore compositional similarities among floras. We identified 164 plant species that are endemic to the SNSM and that occur above 1700 m.s.m., the largest list of SNSM endemics to date. Overall, the SNSM has lower plant diversity than surrounding mountain ranges but also much lower collection effort, indicating a need for continued botanical exploration of the mountain. Our analysis supported the Massenerhebung effect, with the SNSM showing lower elevational limits when compared to larger mountain ranges. The cloud forest and páramo floras of the SNSM were most similar to those of the Cordillera de Mérida in Venezuela. Our results highlight the importance of increasing efforts to explore and conserve the SNSM’s unique flora.

Nothoscordum Kunth is a New World genus distributed from the United States into South America, where its highest diversity is found in Argentina, Chile, Bolivia, Brazil, Peru, and Uruguay. The circumscription of the genus, as well as the taxa included, has been a source of confusion. The large number of taxa described, combined with incomplete keys to species and the difficulty or impossibility of contrasting published descriptions with type material, and with illustrations when available, has created a deep-rooted taxonomic confusion. The convergence of this challenging scenario with the difficulty of finding diagnostic morphological characters has transformed species circumscription into a formidable task. As a first step toward a comprehensive revision of Nothoscordum, a description and nomenclatural account of Nothoscordum sect. Gracilia (Aiton) Sassone, S. Arroyo & P. Moroni (including the cosmopolitan weed N. gracile (Aiton) Stearn) is addressed. Following an extensive review of specimens covering the entire distributional range of the section, a list of names and their types is provided here. It also entails the lectotypification of 10 names, alongside the designation of eight neotypes and one epitype. Fifteen names are synonymized. Additionally, six doubtful species are discussed and one excluded.

Lauraceae are a diverse family of the Neotropical flora that have recently undergone extensive taxonomic changes in the delimitation of genera. Here we review 30 currently accepted Neotropical genera of Lauraceae based on the combination of vegetative and reproductive characters, with a focus on floral characters. We present an identification key, as well as diagnostic descriptions, number of species, distribution, and phylogenetic information for the accepted Neotropical genera.

The “Pacific” clade of Eryngium L. is a group comprising ca. 40 species that grow in Australia, Chile, the western United States, and east-central South America. Taxonomic studies of the American lineages of this clade have recently been published. However, the Australian species of Eryngium have not been taxonomically revised for more than a century. The objective of this study was a taxonomic revision of the Eryngium species native to Australia, including an analysis of their conservation status. For this, the morphology, geographic distribution, and habitat of ca. 550 herbarium specimens were analyzed. In addition, the conservation status of each species was informally evaluated following the IUCN Red List categories and criteria of the International Union for Conservation of Nature. In total, nine Eryngium species native to Australia are recognized, eight of which are endemic. A key for the recognition of these species is provided. For each species, a list of accepted synonyms, a morphological description, an illustration, a distribution map, and a discussion of habitats are presented. Two new synonyms are proposed, a new combination is presented, and nomenclatural problems are analyzed and resolved, including the typification of seven names. The morphological analyses of this study show that the majority of Eryngium species from Australia are heterophyllous. This characteristic had been reported previously for only two Australian Eryngium species. Two of the nine Australian species of Eryngium were found to be in a threatened category.

Pierfelice Ravenna was a controversial Chilean botanist active from the late 1960s through the first decade of the 21st century. He died in 2022. During his active years he described ca. 650 species and infraspecific taxa of plants, mostly in Amaryllidaceae and Iridaceae. Unfortunately, the fate of his type specimens, a majority of which were located in his personal herbarium along with many loans from other herbaria, is not clearly known, but by all indications they were destroyed. In this article, we briefly review his life, compile an annotated list of all validly published specific and infraspecific taxa that he described, and determine which have available holotypes and isotypes.

Lippia L. is the largest genus in Verbenaceae, with ca. 140 species distributed mainly in temperate and tropical South America and the Caribbean, and some lineages in Africa and Asia. A complete taxonomic revision of Lippia in Paraguay is here provided, based on the study of almost 700 herbarium specimens. As a result, 27 taxa, 25 species (two endemic), and two varieties are here recognized. A key for species identification is provided, plus detailed morphological descriptions, illustrations, photographs, updated synonymy with eight new synonyms, discussion about the relationships among closely related taxa, notes on geographic distribution and ecology, distribution maps, and a list of selected specimens analyzed. Fifteen lectotypes are designated for Lantana aristata Schauer var. brachypoda Briq., Lantana aristata (Schauer) Briq. var. latiuscula Briq., Lippia aristata Schauer f. pluripedunculata Kuntze, Lippia balansae Briq., Lippia calliclada Briq., Lippia citrata Cham., Lippia globiflora (L’Hér.) Kuntze f. lilacina Kuntze, Lippia gracilis Schauer, Lippia heterophylla Briq. var. ciliatifolia Briq., Lippia lasiocalycina Cham., Lippia recolletae Morong, Lippia tegulifera Briq. var. parvifolia Briq., Lippia turnerifolia Cham. var. camporum Griseb., Lippia villafloridana Kuntze, and Verbena globiflora L’Hér. Four second-step lectotypes are designated for Lippia lupulina Cham., Lippia morongii Kuntze, Lippia obscura Briq., and Lippia phryxocalyx Briq.