Annals of the Missouri Botanical Garden

Toward a New Generic Delimitation in Polygalaceae III: Chamaebuxus, Chodatia, Heterosamara, and Paivanthus

José Floriano Barêa Pastore — 2026-03-06

The Chamaebuxus alliance (Polygalaceae) comprises the Old World genera Heterosamara Kuntze, Chamaebuxus Tourn. (formerly known as Polygaloides Haller), and Polygala L. subg. Chodatia Paiva and represents the last unresolved lineage of Polygala s.l. that has not yet been comprehensively analyzed in a phylogenetic study. Based on phylogenetic and morphological evidence, we accommodate these taxa into four distinct genera: Chamaebuxus, Chodatia (Paiva) J. F. B. Pastore, comb. & stat. nov. (elevated to genus rank), Heterosamara, and Paivanthus J. F. B. Pastore, gen. nov. Phylogenetic trees were inferred using target enrichment data with Angiosperms353 probes, complemented by data from the maternally inherited plastid loci and the biparentally inherited nrITS region. A strongly supported topological incongruence was observed between the plastid and nuclear datasets for the African genus Paivanthus, which was recovered as sister to Chodatia in plastid analyses, but as sister to the Asiatic genus Heterosamara in nuclear analyses. This incongruence suggests a likely hybrid origin for the African lineage formerly included in Heterosamara. Here, Polygala subg. Chodatia is raised to generic rank, encompassing the species formerly alternatively assigned to Polygala sect. Arillus S. K. Chen. Within Chamaebuxus, we recognize two sections: the Old World section Chamaebuxus and the North American monotypic section Triclisperma (Raf.) J. F. B. Pastore. Two genera are now recognized as having heteropolar pollen: Heterosamara s. str. and Paivanthus, which includes African species previously assigned to Heterosamara. The genus Heterosamara is further subdivided into five sections: section Ecristata J. F. B. Pastore (newly described), section Heterosamara, section Saxicola S. K. Chen, section Spathulata J. F. B. Pastore (newly described), and section Villososperma C. Y. Wu & S. K. Chen. A taxonomic key is provided for the genera Chamaebuxus, Chodatia, Heterosamara, Paivanthus, and Polygala, along with their infrageneric taxa. Photographic plates, a distribution map, 15 new lectotypes, six second-step lectotypes, two new heterotypic synonyms, 41 new combinations, and nomenclatural notes are also presented.

Rubiacearum Americanarum Magna Hama Pars LV. Overview with a Revised Circumscription of Palicourea sect. Heteropsychotria (Palicoureeae)

Charlotte M. Taylor — 2026-04-28

Many of the species classified in Psychotria L. subg. Heteropsychotria Steyerm. have been shown to belong to Palicourea Aubl. based on morphological and molecular characters. Here, species corresponding to Psychotria sect. Heteropsychotria Steyerm. are studied. This section is circumscribed here differently than by Borhidi, to include 29 species found from Mexico and the Antilles to southeastern Brazil with centers of diversity in northeastern South America and the Greater Antilles. This section is not easily diagnosed morphologically because its features are ancestral and widespread in Palicourea, but it can be characterized generally by the combination of stipule form, inflorescence arrangement, and corolla and fruit details. Here several species have revised taxonomic circumscriptions and names, seven new nomenclatural combinations are published, seven names are lectotypified, and four new species are described: Pal. laxivenulosa C. M. Taylor and Pal. pseudovenulosa C. M. Taylor are found in the Andes of Ecuador, Peru, and Bolivia, and Pal. chiribiquetensis C. M. Taylor and Pal. hopkinsiana C. M. Taylor are found in the central to western Amazon basin.

Taxonomic Assessment and Neotypification of Salicornia utahensis (Amaranthaceae: Salicornioideae)

Esteban Ramírez Chueca — 2026-07-01

Salicornia utahensis Tidestr. is a perennial halophyte inhabiting saline habitats of the southwestern United States and northern Mexico. The original type, Kearney & Shantz 3249 (1912; Grantsville, Utah), cited in literature as deposited at US herbarium, is no longer extant, and no duplicates have been located despite extensive searches. In July 2025, we visited the area near Grantsville corresponding as closely as possible to the locus classicus in order to assess extant populations and collect representative material in optimal phenological condition. A neotype is designated here in accordance with Articles 7.11, 9.8, 9.13, and 9.19(a) of the International Code of Nomenclature (Turland et al., 2025) to ensure nomenclatural stability and maintain the traditional usage of the name. In addition, we provide morphological, micromorphological, ecological, and ETS-based phylogenetic evidence, which further clarifies the identity and taxonomic position of the species.

Taxonomic Novelties in Aniba (Lauraceae) with Notes on Stamen Diversity

Rosa del C. Ortiz — 2026-07-01

Our recent herbarium work yielded various undescribed species in the genus Aniba Aubl. (Lauraceae); four of them are described here. Aniba fasciculiflora R. Ortiz & van der Werff, A. sanchezvegae R. Ortiz & van der Werff, and A. tunquiana R. Ortiz & van der Werff are from northern Peru, and A. villosior R. Ortiz & van der Werff is from central Bolivia. The new species are compared with morphologically similar species and distinguished from them by unique combinations of characters, of which the most relevant are flower arrangement, flower shape, and stamen features. We reinstate three taxa that were previously placed in synonymy: A. gigantifolia O. C. Schmidt, A. murcana C. K. Allen, and A. simulans C. K. Allen. We also investigate stamen diversity in Aniba and explore its usefulness in distinguishing species in the genus. By their type of stamen, the newly described and reinstated species all belong to the Aniba affinis group.

Taxonomic and Morphometric Studies of Taxa from the Nissolia brasiliensis and N. longiflora Complexes (Leguminosae, Papilionoideae, Dalbergieae)

Renan Pavan Campos — 2026-08-25

Nissolia Jacq. comprises 32 species distributed throughout the Neotropics. Its representatives are vegetatively uniform, making floral and fruit characters essential for species delimitation. This homogeneity, however, results in unresolved taxonomic complexes, especially among species with high morphological similarity, such as N. brasiliensis (Vogel) T. M. Moura & Fort.-Perez and N. longiflora (Benth. ex A. Gray) T. M. Moura & Fort.-Perez. These taxa exhibit not only extensive intraspecific morphological variation but also imprecise delimitation. Resolving such complexes is critical for understanding biodiversity, as they obscure the actual number of species. In this context, the present study aimed to conduct a morphometric and taxonomic investigation of the N. brasiliensis–N. longiflora complex. We combined classical taxonomic approaches with multivariate analyses, specifically factor analysis of mixed data (FAMD) coupled with hierarchical clustering on principal components (HCPC), using 14 qualitative and 25 quantitative characters from 46 operational taxonomic units (OTUs). We also provide an identification key, distribution maps, photographic plates, and illustrations for the investigated taxa. The results support the recognition of five species within the complex, leading to the proposal of four name reinstatements, six new combinations, and four new synonyms.

Erratum: Toward a New Generic Delimitation in Polygalaceae III: Macropolygala J. F. B. Pastore, a Replacement Name for Chodatia (Paiva) J. F. B. Pastore, Nom. Illeg.

José Floriano Barêa Pastore — 2026-08-25

After publication of our recent article in the Annals of the Missouri Botanical Garden, Volume 111 (published 6 March 2026; Pastore et al., 2026), we discovered that the generic name Chodatia (Paiva) J. F. B. Pastore had already been used for an algal genus, Chodatia Hansgirg (1903). Because algae are governed by the same International Code of Nomenclature for algae, fungi and plants, Chodatia (Paiva) J. F. B. Pastore is therefore a later homonym and illegitimate under Article 53.1 of the Code (Turland et al., 2025). As the name commemorates the Swiss botanist Robert Hippolyte Chodat (1865–1934), whose work was particularly important in Polygalaceae but also extended to other angiosperms and to phycology, especially green algae, the prior use of the name in algae is perhaps not surprising. We therefore provide the necessary correction and propose Macropolygala J. F. B. Pastore as a replacement name (nomen novum) for Chodatia (Paiva) J. F. B. Pastore.

The following nomenclatural changes are therefore required.

Cypselae of Canary Island Tolpis (Asteraceae: Cichorieae): Populational Variation, Biogeography, and Taxonomic Utility

Daniel J. Crawford — 2026-08-25

Tolpis Adans. (Asteraceae: Cichorieae) is a small monophyletic clade in the Macaronesian archipelagos, the larger of two subclades occurring in the Canary Islands. Variation in setae number and body lengths of cypselae, which ostensibly function in dispersal and establishment, were studied to assess their biogeographic and ecological implications, and their taxonomic utility. The Tukey post-hoc test assessed differences in cypselae among populations on each island, means among islands, and differences among taxa. El Hierro populations share the same Tukey group for both characters; there are differences among populations on both La Gomera and La Palma. Setae number is variable on geologically complex Tenerife with five Tukey groups in the sampling from different substrates, areas of the island, and taxonomic designations. Mean values for cypsela characters do not differ among El Hierro, La Gomera, and La Palma; Tenerife has larger cypselae and higher setae numbers than the other three islands. Population variation in cypselae limits their use as characters for delimiting taxa; however, variation associated with geological substrates and potential dispersibility were noted. The commonly reported larger cypselae of insular lineages compared to closest continental relatives are not seen in Canarian Tolpis.

Five New Bullate-leaved Species of Peperomia (Piperaceae) from Colombia

José Esteban Jiménez — 2026-08-25

We describe and illustrate five new species of bullate-leaved Peperomia Ruiz & Pav. from Colombia: P. arboretorum J. E. Jiménez, Díaz-Rueda & J. P. Tobón-A. from Antioquia, P. boyacensis J. E. Jiménez & D. Amaya from Boyacá, P. bullatifolia J. E. Jiménez, Edwin Trujillo & Villanueva from Caquetá, P. guanesorum J. E. Jiménez & D. Sanín from Santander, and P. vallecaucana J. E. Jiménez from Valle del Cauca. Together with previously known taxa, these discoveries raise to 10 the number of Colombian species with bullate leaf blades, a phenotype that has likely been underestimated because it is often obscured in herbarium material. All known bullate-leaved species are terrestrial, restricted to shaded understory habitats, and most are allopatric montane endemics. We combine detailed field observations, herbarium studies, and a phylogenetic framework to aid description of these species and understand the evolution of bullate-leaved Peperomia. Four new species for which molecular data are available are placed in Peperomia subg. Multipalmata Scheiris & Frenzke, whereas P. vallecaucana is inferred, based on morphology, to belong to subgenus Perlucida Scheiris & Frenzke. Additional sampling of three previously described bullate-leaved species was also added to the phylogeny. Our results demonstrate that bullate leaves in Colombian Peperomia have evolved at least three times independently and are concentrated in two major lineages, Multipalmata and Perlucida. We recognize two main venation-related bullation patterns and highlight the potential adaptative significance of this trait in humid, low-light montane forests. For each new species, we provide a morphological description, notes on distribution, habitat, and a preliminary IUCN conservation assessment. Photographs and illustrations of all the living plants are also included, as well as a key to identify the species with bullate leaf blades in Colombia.

Revisiting the Taxonomy of the Widespread Neotropical Moonseed Abuta grandifolia: Insights from the Morphological and Molecular Data

Rosa del C. Ortiz — 2026-11-03

Species that are geographically widely distributed and morphologically variable present considerable challenge when evaluating their taxonomic boundaries. The Neotropical moonseed Abuta grandifolia (Mart.) Sandwith species group is one example of such a widespread and morphologically variable nominal taxon. The species group is widely distributed in the Amazon basin, Guianas, and extra-Amazon region in Brazil. It is well known for its various ethnobotanical uses, and although earlier preliminary morphological investigations suggested that it may comprise more than one species, its taxonomic limits have remained uncertain.

In this study, we explore taxonomic boundaries within the Abuta grandifolia species group by integrating morphological and molecular data. Variation in vegetative and reproductive morphological traits was investigated at a continental scale among our four pre-established morphological groups. Molecular variation was explored among co-occurring morphological groups at local and regional scales in Western Amazonia in Peru. Our morphometric analysis clearly distinguished two of the four morphological groups where significant traits differentiating them are mostly vegetative. Phylogenetic analyses based on four markers (ITS, trnL-F, trnH-psbA, and rps16) recovered four clusters that correspond to the four groups. Our results confirm previous studies regarding the presence of distinguishable taxonomic units within the widespread A. grandifolia s.l. These may correspond either to species already described and thus in need of reinstatement or to new species in need of description.

Rubiacearum Americanarum Magna Hama Pars LVI. Overview of the New Group Palicourea sect. Inundatae with Some New Species

Charlotte M. Taylor — 2026-11-02

Many of the species classified in Psychotria L. subg. Heteropsychotria Steyerm. have been shown to belong to Palicourea Aubl. based on morphological and molecular characters. The species studied here belong to a group that was recognized previously as Psychotria ser. Inundatae Müll. Arg., and is treated here as Palicourea sect. Inundatae (Müll. Arg.) C. M. Taylor. This section can be recognized by the combination of leaves without domatia in the abaxial secondary vein axils; distinctive stipules; terminal inflorescences that are not displaced to pseudoaxillary and have a subcapitate to cymose arrangement with regularly well-developed, showy, generally white bracts; subsessile, 4- or 5-merous flowers; a short calyx limb; funnelform or tubular-funnelform, white, thin-textured corollas with the tube not swollen at the base; medium-sized, juicy, black or purple-black fruits; and pyrenes abaxially with four or five broadly angled to narrow ridges and adaxially with a broad concave face or a plane face with a medial furrow that is often broadened inside. The stipules are well developed and have a prominent appendage that is inserted at the base and appears to comprise the entire stipule but actually arises from a short abaxial sheath portion. The 25 species included here range from Belize to Bolivia and southern Brazil, with centers of diversity in the Guayana Highlands region of northeastern South America and the western Amazon basin. The taxonomy of several of these species has been problematic, and they are circumscribed differently here than by previous authors. Plants that have been treated previously in a broadly circumscribed Psy. capitata Ruiz & Pav. are here separated into several different species and none take this epithet, because this name has been misinterpreted and does not apply to any species of this group. A nomenclatural summary, key, and morphological discussions clarify the identities of these names and separation of species of this group. Nine new species and one new subspecies are described here: Pal. aguilarii C. M. Taylor is found in southern Costa Rica and western Panama; Pal. berliniana C. M. Taylor is found in northeastern Peru; Pal. calimana C. M. Taylor is found in western Colombia; Pal. crucifera C. M. Taylor is found in east-central Bolivia; Pal. inundata (Benth.) C. M. Taylor subsp. maynasana C. M. Taylor is found in northeastern Peru; Pal. liesneri C. M. Taylor is found in northeastern South America; Pal. neeana C. M. Taylor is found in eastern Bolivia; Pal. palcazuana C. M. Taylor is found in southeastern Peru; Pal. pampana C. M. Taylor is found in southern Peru and northern Bolivia; and Pal. teranii C. M. Taylor is found in eastern Bolivia. Twelve new sectional, species-level, and infraspecific nomenclatural combinations are made here: Palicourea sect. Inundatae, Pal. albonervia (Standl.) C. M. Taylor, Pal. bracteata (Kuntze) C. M. Taylor, Pal. calochlamys (Standl.) C. M. Taylor, Pal. chlorotica (Müll. Arg.) C. M. Taylor, Pal. guanchezii (Steyerm.) C. M. Taylor, Pal. guarupana (Standl.) C. M. Taylor, Pal. homoplastica (S. Moore) C. M. Taylor, Pal. inundata, Pal. ovatistipula (C. M. Taylor) C. M. Taylor, Pal. roraimensis (Benth.) C. M. Taylor, and Pal. roraimensis subsp. septentrionalis (Steyerm.) C. M. Taylor. Seven names are newly typified here: Psychotria ser. Capitatae Hook. f., Cephaelis guarupana Standl., Pal. cyanea Urb., Psy. chlorotica Müll Arg. var. bahiensis Müll Arg., Psy. chlorotica var. lanceolata Müll. Arg., Psy. chlorotica var. obovata Müll. Arg., and Psy. duckei Standl.