Annals of the Missouri Botanical Garden

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

Fri, 06 Mar 2026 06:09:14 +0000

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, Andreas Berger — Tue, 28 Apr 2026 13:44:33 +0000

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, Vicenta de la Fuente, Daniel Sánchez-Mata — Wed, 01 Jul 2026 13:32:29 +0000

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, Henk van der Werff — Wed, 01 Jul 2026 13:36:35 +0000

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.