The use of phylogeny to interpret cross-cultural patterns in plant use and guide medicinal plant discovery: an example from Pterocarpus (Leguminosae)

The study of traditional knowledge of medicinal plants has led to discoveries that have helped combat diseases and improve healthcare. However, the development of quantitative measures that can assist our quest for new medicinal plants has not greatly advanced in recent years. Phylogenetic tools have entered many scientific fields in the last two decades to provide explanatory power, but have been overlooked in ethnomedicinal studies. Several studies show that medicinal properties are not randomly distributed in plant phylogenies, suggesting that phylogeny shapes ethnobotanical use. Nevertheless, empirical studies that explicitly combine ethnobotanical and phylogenetic information are scarce.In this study, we borrowed tools from community ecology phylogenetics to quantify significance of phylogenetic signal in medicinal properties in plants and identify nodes on phylogenies with high bioscreening potential. To do this, we produced an ethnomedicinal review from extensive literature research and a multi-locus phylogenetic hypothesis for the pantropical genus Pterocarpus (Leguminosae: Papilionoideae). We demonstrate that species used to treat a certain conditions, such as malaria, are significantly phylogenetically clumped and we highlight nodes in the phylogeny that are significantly overabundant in species used to treat certain conditions. These cross-cultural patterns in ethnomedicinal usage in Pterocarpus are interpreted in the light of phylogenetic relationships.This study provides techniques that enable the application of phylogenies in bioscreening, but also sheds light on the processes that shape cross-cultural ethnomedicinal patterns. This community phylogenetic approach demonstrates that similar ethnobotanical uses can arise in parallel in different areas where related plants are available. With a vast amount of ethnomedicinal and phylogenetic information available, we predict that this field, after further refinement of the techniques, will expand into similar research areas, such as pest management or the search for bioactive plant-based compounds

Long-term thermal sensitivity of Earth’s tropical forests

The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia

Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state

Revision and biogeography of centrolobium (Leguminosae - Papilionoideae)

A taxonomic revision and biogeographic study of the genus Centrolobium (Leguminosae - Papilionoideae) is presented. Centrolobium includes important timber trees distributed disjunctly in seasonally dry tropical forests and rain forests in Central and South America, from Panama to south-eastern Brazil. It is characterized by large samaroid pods with a spiny seed case and an abundance of orange peltate glands covering the leaves and inflorescences. Taxonomic distinctions between some species of Centrolobium in have been a source of confusion. Here, seven species are recognized: C. robustum, C. microchaete, C. tomentosum, C. ochroxylum, C. sclerophyllum, C. paraense, and C. yavizanum. Previously recognized varieties of C. paraense, C. paraense var. paraense and C. paraense var. orinocense, are not maintained. Phylogenetic analysis of DNA sequence data from the internal transcribed spacer region of nuclear ribosomal DNA and the plastid mat K gene an trnL-trnF intron and spacer support the monophyly of the genus. Different molecular dating methods indicate that the Centrolobium crown group and lineages found to the west and cast of the Andes diverged before the Pleistocene. Divergences between species occurring east of the Andes, particularly in Bolivia and south-eastern Brazil are more recent, but nevertheless unlikely to be explained by Pleistocene climatic changes

Handroanthus abayoy Villarroel & G. A. Parada. A. Leaves. B. Flowers 2022, sp. nov.

Handroanthus abayoy Villarroel & G.A.Parada, sp. nov. (Figure 1; Figure 2) Type: — BOLIVIA. Santa Cruz, Provincia Germán Busch: afloramiento rocoso, zona del Calvario del Carmen Rivero Torrez, 18.809112°S, 58.619919°W, 211 m, 11 July 2021, fl, G . A. Parada 5609 (holotype USZ!, isotypes K!, LPB!, MO!). Handroanthus abayoy is similar to H. selachidentatus but differs in the absence of lepidote scales, stellate trichomes and resinous exudate on the calyx and branches; and in the basally asymmetrical leaflets, lateral petiolules 1–2.5(–3) cm long, and in the blades with margins entire, repand, crenulate or slightly serrate, mainly at the apex, and also in the inflorescences and flowers with dendroid trichomes, and in the pulverulent calyx. Tree, 1–3 m tall when growing on rocky outcrops, 2–8 m tall when growing on sandy soils in the lowland plains, and up to 15 m at the foot of mountains and on plateaus; stems> 5 cm dbh (diameter at breast height), bark strongly fissured, woody rhytidome, yellowish-coloured; apical branches cylindrical or slightly subtetragonal, glabrous and with scattered lenticels; leaf buds and the extreme apices pulverulent, with whitish dendroid trichomes. Leaves 1–3-foliolate, opposite, petiole 3.5–5(–6) cm long, 2–3 mm diametre, canaliculate; lateral leaflets with petiolules 1–2.5(–3) cm long, canaliculate, blades 4–7.5(–8) × (2.3–)2.5–4 (–4.5) cm, elliptical, ovate or orbicular, base asymmetric to slightly asymmetric, obtuse or rounded, sometimes truncate, apex acuminate or cuspidate; terminal leaflets with petiolules (1.5–) 2–3.5 cm long, canaliculate, blades 5.5–8(–10) × 3–4.5(–5.5) cm, elliptical, ovate or orbicular, sometimes oblanceolate, coriaceous, glabrous, base asymmetrical, obtuse or rounded, sometimes truncate, apex acuminate or cuspidate; margin strongly cartilaginous, entire, repand, crenulate or slightly serrate (mainly at the apex), discolorous, the upper surface glaucous green or dark green and lustrous, the lower surface light green and cinereous, both surfaces with visible scattered flat and circular nectaries, with visible translucent glands, dispersed, 0–2 per mm 2; midvein slightly sulcate on the upper surface, prominent on the lower surface; secondary veins 6–10-paired, brochidodromous or cladodromous, arched, angle of divergence 30–45°, prominent on both surfaces; tertiary veins reticulate, prominent on both surfaces. Inflorescences paniculate, terminal, with 6–11 flowers per panicle; peduncle pulverulent, trichomes dendroid and whitish; bracts and bracteoles deciduous, 1–1.5 mm long, concave and deltoid, apex acute, pulverulent on both surfaces (whitish trichomes, dendroid), the margin ciliate, trichomes dendroid and whitish. Flowers pedicellate, pedicel articulate, 2–3 mm long; calyx cupular, 4–5.5 mm long, 4–5 mm wide in the middle, 5-lobed, the lobes irregular, c. 1–1.5 mm long, slightly concave, the apex rounded or acute, margin entire, not ciliate, both surfaces dark purple-coloured, the exterior pulverulent with whitish dendroid trichomes, the interior glabrous or glabrescent; corolla tubular-infundibuliform, 4.5–5.5 cm long, floral tube 3–4.5 cm long, exterior white at the base and pink or magenta along the tube, pilose or pubescent (trichomes dendroid and whitish), interior white but with yellow patches in the throat, glabrous or glabrescent (trichomes dendroid and whitish), 5-lobed, the lobes 1.5–2 cm long, 1–1.5 mm wide at the base, pink or magenta on both surfaces, the apex rounded, pilose or pubescent on both sides, margin sinuous and ciliate (trichomes dendroid and whitish); stamens 4, inserted, free part of the dorsal filaments 1–1.3 cm long, free part of the ventral filaments 1.5–1.8 cm long, free part glabrous, adnate part tomentose with glandular trichomes, anthers glabrous, thecae c. 2.5–3 × 1 mm; ovary 2-locular, c. 3.5–4 × 1–1.5 mm, linear-oblong in outline, not ribbed, 2–3 series of ovules per locule, 11–14 ovules per locule; nectary disk annular; style 3–3.5 cm long, glabrous, stigma bifid, lobes c. 1.5 × 1 mm, glabrous. Fruits linear capsules, 15–22 × 0.5–1 cm, cylindrical in cross section, glabrous or glabrescent; valves membranous, smooth; calyx persistent. Seeds bialate, 0.5–0.8 × 2–3.5 cm, the wings hyaline-membranaceous, sharply demarcated from darker seed body. Paratypes:— BOLIVIA. Santa Cruz, Prov. Chiquitos: 25 km al S de San José, camino a las Salinas, 300 m, 27 August 1997, fl, A . Fuentes & G. Navarro 2047 (LPB!, USZ!); Serranía de Santiago de Chiquitos, senda a Soledad, 18°21.11’S, 59°35.5’W, 622 m, 2 March 2007, st, P . Pozo 370 (LPB!); Santiago de Chiquitos, ca. 2 km de Santiago de Chiquitos en el camino hacia Roboré, 18°20’S, 59°36’W, 500 m, 3 September 2007, fl, J . R. I. Wood 23375 (LPB!, USZ!); subida de Santiago a 3 kilómetros de la plaza en el camino a Roboré, 18.2014°S, 59.36307°W, 612 m, 7 October 2008, fr, J . R. I. Wood & P. Pozo 25078 (K, LPB, USZ!); carretera entre Roboré y Aguas Calientes, 18°23’45.8”S, 59°39’12.9”W, 260 m, 5 September 2020, fl/fr, D. Villarroel 6265 (LPB, USZ!); carretera entre Roboré y San José de Chiquitos, ca. 2 km al NW de Ipiás, 18°01’41”S, 60°11’52.7”W, 415 m, 31 July 2021, fl, D. Villarroel 6274 (USZ!, K, LPB); Prov. Germán Busch: a 700 metros aprox. de la carretera Ruta 4, sobre bosque bajo sobre arenales (abayoy), 18.799008°S, 58.664673°W, 174 m, 20 September 2020, fr, G . A. Parada 5484 (LPB, MO, USZ!). Distribution, habitat and phenology:— Handroanthus abayoy is an endemic species of the southern part of the Department of Santa Cruz (Bolivia), occurring in the municipalities of Roboré and San José de Chiquitos of Chiquitos Province and the municipality of Carmen Rivero Torrez in Germán Busch Province. It is a deciduous tree, typical of the abayoy vegetation, that is distributed between 150–600 m elevation and bordered to the west and south by the Chaco vegetation, to the east by the Pantanal wetlands, and to the north by the Cerrado and Chiquitano Dry Forest (Ibisch et al. 2003, Navarro 2011, Villarroel et al. 2016). The abayoy vegetation develops on plains with quaternary sediments, where the soils are deep, sandy, acidic and well drained. Biogeographically, the abayoy vegetation has a high floristic affinity with the Cerrado, although it also presents floristic elements typical of the Chaco. Handroanthus abayoy is a frequent and relatively abundant species [9±5 tree/ha, value calculated from Villarroel et al. (2010), Villarroel et al. (2021)]. Due to the glaucous-green colour of its leaves, as well as the color of its flowers, H. abayoy is a conspicuous element of the landscape. Although with lesser frequency, it also inhabits in the cerrado rupestre and the cerradão in the Serranía Chiquitana between 300 and 650 m [the habitats or phytophysiognomies follow the classification of Ribeiro & Walter (2008) and Villarroel et al. (2016)]. Handroanthus abayoy start flowering in the middle of the dry season (July), produces flowers until early September, at the end of the dry season. Fruiting occurs between the end of the dry season and the beginning of the wet season (September and October). Etymology:—The specific epithet “ abayoy ” refers to the main type of vegetation where the species lives, the abayoy, a word from the Bésiro language that means dwarf forest. This type of vegetation has a series of biotic and abiotic characteristics that differentiate it from the Pantantal, the Chaco and the Chiquitano Dry Forest; being, biophysically more similar to the Cerrado (Ibisch et al. 2003, Navarro 2011, Villarroel et al. 2016). Conservation status:—All records of Handroanthus abayoy are restricted to the southern region of the department of Santa Cruz, Bolivia (Figure 3). It is known from eight localities, one of these within the Tucabaca Conservation and Natural Heritage Unit (UCPN), another within the Santa Cruz la Vieja UCPN, and two within the Ñembi Guasu Conservation and Ecological Importance Area (Figure 3). The extent of occurrence (EOO) of the species is 9,195.1 km 2, and the area of occupancy (AOO) 40 km 2. Currently, the populations that inhabits the cerrado rupestre and the cerradão in the Serranía Chiquitana have low human pressure (it grows on rocky outcrops, serpentine soils or on shallow soils on the Precambrian Shield). However, the populations that inhabit the abayoy vegetation are threatened by agricultural and livestock expansion and have also been severely affected by forest fires in 2019 (Villarroel et al. 2021). Therefore, H. abayoy should be categorized as Vulnerable [VU B2 ab (iii)], according to IUCN criterion B2 (AOO <2,000 km 2) (IUCN 2019); sub-criteria a, number of locations ≤10; and the sub-criteria b (iii), continuous decrease in the area of extension and / or quality of habitat (deforestation and forest fires). Affinities:— Handroanthus abayoy is similar to H. selachidentatus. The latter is currently recognized in the Catalogue of Vascular Plants of Bolivia (Jørgensen et al. 2015 onwards) based on the publication by Fuentes-Claros (1998). However, the specimen cited by Fuentes-Claros (1998) corresponds to H. abayoy. Both species are part of Tabebuia group II in the clades proposed by Grose & Olmstead (2007), because of the cupular 5-lobed calyx and magenta flowers with a yellow throat. However, both species have a series of morphological (vegetative and reproductive) and biogeographic characteristics that distinguish them one from another (Table 1).Published as part of Villarroel, Daniel, Parada, G. Alexander, Martinez-Ugarteche, Maira T. & Klitgaard, Bente B., 2022, Handroanthus abayoy, a new species of Bignoniaceae endemic from Bolivia, pp. 97-104 in Phytotaxa 547 (1) on pages 98-103, DOI: 10.11646/phytotaxa.547.1.9, http://zenodo.org/record/655673

A linear sequence to facilitate curation of herbarium specimens of Annonaceae

This paper provides a linear sequence of four subfamilies, 15 tribes and 106 genera of the magnoliidfamily Annonaceae, based on state-of-the-art and stable phylogenetic relationships. The linear sequence facilitatesthe organisation of Annonaceae herbarium specimens