Abstract— We provide a comprehensive taxonomic treatment for Evolvulus sect. Lagopodini that includes species with flowers congested in terminal inflorescences and bracts similar to sepals. In this section, we recognized five species distributed mainly in the Dry Forests and in the Brazilian Savanna of South America, with greater diversity in the Brazilian Savanna (three species). We analyzed around 550 sheets deposited in 42 herbaria, including types for all accepted names and synonyms. We propose two synonyms for E. pterygophyllus , one for E. niveus ; and lectotypes for E. lagopodioides , E. pterocaulon , E. pterocaulon var. flocosus , and a second-step lectotype for E. pterygophyllus . An identification key, complete descriptions, illustrations, distribution map, and preliminary conservation status assessment for all species are provided.

Abstract— Taxonomic uncertainties in rare species can hinder effective conservation planning and prioritization. Lithocarpus dahuensis was described in 2023 as an endemic species based on a single population from Minhou County, Fujian Province, China, and was assessed as an endangered species. However, its morphology closely resembles that of L. konishii , raising doubts about its taxonomic distinctiveness. To clarify this taxonomic ambiguity, we used whole-genome resequencing data from 20 samples, including 3 of L. dahuensis and 6 of L. konishii , to reconstruct the phylogenomic tree. In parallel, we examined leaf morphology using geometric morphometrics and a neural network classifier to evaluate morphological differentiation between the two taxa. Phylogenomic analyses revealed that all L. dahuensis individuals formed a small lineage nested within L. konishii , and morphological analyses showed substantial overlap in leaf traits. These findings demonstrate that L. dahuensis is conspecific with L. konishii and should be treated as its synonym. The Minhou population thus represents the northernmost records of L. konishii , and its presence constitutes a new distribution record for Fujian Province. Given the overall rarity and significant geographic isolation of L. konishii populations, we recommend both in situ and ex situ conservation efforts for the species.

Abstract— Teucrium danxiacola (Lamiaceae), a new species endemic to the Danxia landform of Jiangxi Province, eastern China, is described and illustrated here. Molecular phylogenetic analyses based on five plastid markers ( matK , rbcL , rps16 , ndhF and trnL-trnF ) and nuclear ribosome ITS sequence data confirm its systematic placement within the genus Teucrium . Morphologically, the new species resembles T. viscidum and T. veronicoides , but is distinguished by the following characters: subcordate leaf base (vs. rounded to cuneate in T. viscidum ; truncate to subcordate in T. veronicoides ); a calyx covered with white spreading villous hairs (vs. glandular villous in T. viscidum ; subglabrous in T. veronicoides ) and posterior lateral lobes of the corolla bearing white spreading villous hairs (vs. subglabrous in both T. viscidum and T. veronicoides ).

Abstract— Cuscuta nuwuviana , a new species from southwest Utah and northwest Arizona is described and illustrated. The phylogenetic analyses revealed that the new species belongs to a subclade of C. sect. Californicae (subg. Grammica ) that also includes C. draconella and C. decipiens . Although not statistically significant, a topological incongruence between the plastid and nuclear data suggests that C. draconella resulted from the homoploid hybridization of C. nuwuviana and C. decipiens , accompanied by plastid introgression. Optical and scanning electron microscopy were employed to morphologically distinguish C. nuwuviana from C. draconella and C. decipiens , and an identification key was provided. Field investigations allowed the description of the habitat and plant community of the new species, which is currently known from only two populations in which it parasitizes solely Gutierrezia microcephala (Asteraceae). Evolutionary relationships, infrastaminal scales, and the presence of floral stomatiferous protuberances in C. sect. Californicae are discussed.

Abstract— Amauropelta stands as the most diverse genus of Thelypteridaceae with 233 species in four recognized subgenera. Among these, Amauropelta subgen. Amauropelta includes A . sect. Lepidoneuron , which has scandent leaves. Historically, species delineation has been challenging in this section. Recent explorations in Colombian páramos have uncovered the need for two new combinations in A. sect. Lepidoneuron from the region: Amauropelta sunduei and Amauropelta atropurpurea . Additionally, our investigations have revealed a new synonym and a new distribution record for Amauropelta laevigata. A lectotype is also assigned for one of the synonyms of Amauropelta laevigata . We present descriptions, line drawings of Amauropelta sunduei , preliminary conservation status for species restricted to Colombia, macro- and microphotographs, distribution maps, and a key for all species discussed.

Abstract— Macropsychanthus currently comprises 51 species and is divided into two subgenera, M. subg. Macropsychanthus and M. subg. Platylobium , which are distinguished by a combination of morphological traits and supported by molecular data. However, certain species present morphological features typical of M. subg. Platylobium despite their phylogenetic placement within M. subg. Macropsychanthus . During our comprehensive revision of Macropsychanthus in the Neotropics, we discovered a new species, here named Macropsychanthus echidna . Phylogenetic analyses based on nuclear ITS/ETS and plastid trnK/matK markers recovered it within M. subg. Macropsychanthus . Nevertheless, the species displays traits such as triangular, basifixed stipules; exstipellate leaflets with 7‐9 pairs of secondary veins; and slightly obovate pods, all features typically associated with M. subg. Platylobium . Together with Macropsychanthus huberi , this is the second species assigned to M. subg. Macropsychanthus that displays a morphology largely aligned with M. subg. Platylobium , thereby challenging the validity of maintaining the current subgeneric delimitation. The short, oblong hilum of the seed remains the only consistent morphological feature distinguishing M. subg. Platylobium .

Abstract— Comarostaphylis is an endemic genus to North America, with a geographical distribution ranging from California to Panama. Ten species of Comarostaphylis are recognized, seven of which are endemic to Mexico. Comarostaphylis discolor comprises four subspecies, including C. discolor subsp. macvaughii , a perennial dwarf shrub endemic to isolated populations in the mountains near Tapalpa, Jalisco, Mexico. Based only on a morphology study, this subspecies was elevated to species rank but not recognized by some authors. In this study, we tested the taxonomic rank hypothesis of this subspecies using morphological data as well as molecular data within a phylogenetic framework. A total of 38 accessions of the internal transcribed spacer (ITS) were included in the analysis: three as the ingroup and 35 as the outgroup. Six new individuals were analyzed, three belonging to Comarostaphylis macvaughii and the other three to C. discolor subsp. discolor , all from the same locality. We performed maximum likelihood (ML) analyses using RAxML. Our phylogenetic results support the recognition of C. macvaughii as a monophyletic lineage, sister to the clade comprising C. arbutoides and C. discolor species. Additionally, our preliminary conservation status assessment indicates that it is a critically endangered species.

Abstract— A new tree species of Ecclinusa (Sapotaceae, Chrysophylloideae) from Central Amazonia is described and illustrated. It occurs in non-flooded upland forests (terra-firme) in the municipalities of Manaus, Presidente Figueiredo, and Rio Preto da Eva in Amazonas state, Brazil. Ecclinusa nervosa sp. nov. resembles E. ulei, E. parviflora, and the sympatric E. guianensis, as these species share overall similar foliage at first sight. However, it differs by the combination of the presence of intersecondary veins (vs. absent in all congeners, except in E. lancifolia) and flowers with a sparse tomentulose indumentum inside the sepals (vs. glabrous inside in all congeners, except in E. ramiflora and E. psilophylla) and shorter styles (≤ 0.7 mm long vs. > 0.7 mm long in the morphologically similar taxa). We compare the new species with similar taxa through diagnostic morphological features, geometric morphometrics, and infrared spectral analyses of dried leaves. Additionally, we provide information on habitat, distribution, phenology, and a preliminary conservation assessment. An identification key for Ecclinusa species from the Brazilian Amazonia is also presented.

Abstract— The objectives of this research were to assess variation in nrDNA internal and external transcribed spacer (ITS and ETS) sequences of the morphologically diverse genus Dieteria and to determine how well the results of phylogenetic analysis corresponded with morphological variation, taxonomy, and geographic distribution. The first of two analyses included 39 samples from throughout the range of the genus and representing 13 of the 16 currently accepted varieties, with ITS and ETS sequences combined to obtain the greatest resolution possible. This analysis produced phylogenies containing three major clades. One of the three consisted of samples from Washington, Oregon, and northern California. The second one included samples from southern California and western Arizona, plus additional ones from northern California, northern Nevada, and southeastern Idaho. The third clade was the largest and consisted of samples from the remaining part of the distribution of Dieteria. Comparison of the results with current taxonomy and morphological characteristics showed little correspondence between the molecular phylogeny and either taxonomy or morphology, suggesting multiple occurrences of convergent evolution. There were some correlations with geographic distributions. Except for the second and third clades’ distributions overlapping in some areas, the distributions of the three were mostly distinct from one another; smaller clades within them were also correlated with distributions. The second analysis included cloned sequences of five additional samples that were shown by initial sequencing efforts to contain many polymorphic nucleotide positions. In the results, the ITS and/or ETS for all five samples were placed in multiple positions some distance apart, indicating that these samples obtained their ITS and/or ETS sequences from distantly related ancestors through hybridization between members of two of the three major clades.