Nomenclatural notes on Menthinae (Mentheae - Lamiaceae) native to Brazil

Menthinae, one of the five subtribes of Mentheae (Lamiaceae), with ca. 735 species, is represented in Brazil by a wide range of herbs and shrubs. During an investigation of the taxonomic history of the group for the Flora e Funga do Brasil project, several nomenclatural issues with typifications in the group have been identified. This study attempts to resolve them, making suggestions of new types and re-evaluation of synonyms. Thirteen lectotypifications and one neotypification are being proposed, along with the recognition of Thymus selloi Spreng. ex J.A.Schmidt as a nomen nudum. Most of the suggested changes are due to the loss of many of Sellow's types at B during WWII, lack of specific herbaria references and collector numbers in the protologues, or to existence of designated syntypes in the referred collections. Our study is a contribution to the nomenclatural and taxonomic knowledge of Menthinae, providing a stable foundation for future study of its taxonomy, biogeography, and evolution.

Mentheae (Nepetoideae - Lamiaceae) from the Itatiaia National Park, Brazil

Abstract This study details the floristic diversity of Mentheae (Lamiaceae - Nepetoideae) from the Itatiaia National Park, the first Protected Area in Brazil. Among the 30 species of Lamiaceae cited for the Park, we recorded 15 species belonging to Mentheae arranged in seven genera: Cunila (2 spp.), Hedeoma (1 sp.), Hesperozygis (1 sp.), Lepechinia (1 sp.), Prunella (1 sp.), Rhabdocaulon (1 sp.), and Salvia (8 spp.). The region presents significant diversity, considering the 62 native species of Mentheae recorded in the Brazilian Southeast. The species are distributed in the Park’s different vegetation types, mostly in shaded areas of the ombrophilous forests or throughout high-altitude grasslands. We provide a complete description for each species and an identification key, as well as comments on species distribution, habitat, morphological variation, and phenology.

Phytotoxicity of Schiekia timida Seed Extracts, a Mixture of Phenylphenalenones

Phenylphenalenones, metabolites found in Schiekia timida (Haemodoraceae), are a class of specialized metabolites with many biological activities, being phytoalexins in banana plants. In the constant search to solve the problem of glyphosate and to avoid resistance to commercial herbicides, this work aimed to investigate the phytotoxic effect of the methanolic extract of S. timida seeds. The chemical composition of the seed extract was directly investigated by NMR and UPLC-QToF MS and the pre- and post-emergence phytotoxic effect on a eudicotyledonous model (Lactuca sativa) and a monocotyledonous model (Allium cepa) was evaluated through germination and seedling growth tests. Three concentrations of the extract (0.25, 0.50, and 1.00 mg/mL) were prepared, and four replicates for each of them were analyzed. Three major phenylphenalenones were identified by NMR spectroscopy: 4-hydroxy-anigorufone, methoxyanigorufone, and anigorufone, two of those reported for the first time in S. timida. The presence of seven other phenylphenalenones was suggested by the LC-MS analyses. The phenylphenalenone mixture did not affect the germination rate, but impaired radicle and hypocotyl growth on both models. The effect in the monocotyledonous model was statistically similar to glyphosate in the lowest concentration (0.25 mg/mL). Therefore, although more research on this topic is required to probe this first report, this investigation suggests for the first time that phenylphenalenone compounds may be post-emergence herbicides.

Angiosperms of dry grasslands and savannahs of Jalapão, the largest conserved Cerrado area in Brazil

Abstract This study provides a checklist of angiosperm species from Jalapão region, Tocantins, Brazil, inserted within the Cerrado biome, a global biodiversity hotspot. The region of Jalapão is still well preserved despite current threats to its biodiversity, however its plant diversity is still poorly understood. To generate the present checklist, fieldwork was carried out and relevant herbarium collections were consulted. Angiosperms distributed in the grassland and savanna physiognomies with dry, non-rocky soils were recorded. We detected 550 species within 85 families. The richest families are Leguminosae, Poaceae, Asteraceae, Lamiaceae, Rubiaceae, Myrtaceae, Malpighiaceae and Euphorbiaceae. Among the plant species, ten are listed as rare, ten are threatened, and twelve were identified as new to science. This study increases the number of angiosperm species occurring in these vegetation types in Jalapão almost 2-fold compared to previous inventories. The Cerrado biome and Jalapão region are under heavy threat due to agricultural expansion, and our study contributes to the knowledge of plant biodiversity as a fundamental step towards designing and carrying out conservation actions.