The cashew tree Anacardium occidentale is a globally important food species and in Brazil is a natural component of cerrado and restinga vegetation and has an important role in local economies as a food and medicinal plant. Nevertheless, diversity studies of wild populations—the most important reservoir of natural variation—of this naturally widespread species are urgently needed for conservation strategies because of human impact on tropical American ecosystems where it occurs. Here, we sought to differentiate the previously recognized restinga and cerrado ecotypes using multivariate morphometrics of wild populations in a limited area of northeast Brazil (northern Piauí and northeastern Maranhão states). Thirty individuals were sampled for 47 vegetative and reproductive descriptors from six wild populations (three of each ecotype). Data analysis included principal component analysis and three classification methods (linear discriminant analysis, k-nearest neighbour analysis and classification and regression tree analysis); cross-validation tests were applied to classification results. Univariate statistics obtained for each population and ecotype were found to be consistent with the previously proposed distinction between the two ecotypes. Although principal component analysis showed extensive variation and overlap between populations, cross-validations of classification analyses showed strong differentiation between ecotypes and between most populations; vegetative and reproductive variables were equally important for discrimination. Cerrado populations were more variable and somewhat less distinct than restinga ones. New molecular genetic investigations of wild populations are needed to provide genetic support for the morphological differentiation of the ecotypes reported here.

Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods(1,2). A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome(3,4). Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins(5-7). However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes(8). This 15-fold increase in genus-level sampling relative to comparable nuclear studies(9) provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.

(3048) Stylochiton Lepr. in Ann. Sci. Nat. Bot., ser. 2, 2: 184. 1834 ('Stylochæton') [Angiosp./Ar.], nom., orth. et gen. masc. cons. prop. Typus: S. hypogeus Lepr. ('hypogeum'). Stylochiton is a not very large genus of about 25 species of (sub)tropical African aroid geophytes whose particular botanical and evolutionary significance may be said to lie in their genus's near "basal" position in the almost entirely monoecious subfamily Aroideae (see, e.g., Haigh & al. in Amer. J. Bot. 110: e16117. 2023). They present features, nearly unique in the subfamily, which accord to greater or lesser degree with aspects of the floret morphology of most of the earlier diverging bisexual-floreted subfamilies, including a perianth-like structure around the pistils and male florets which furthermore have the stamens with distinct thread-like filaments. The spelling and gender of masculine, etymologically correct Stylochiton vs. the original neuter, etymologically erroneous Stylochaeton remain an unresolved source of nomenclatural ambiguity 40 years after a proposal similar to this one (Nicolson & Mayo in Taxon 33: 509. 1984) led to no properly decisive nor linguistically plausible recommendation either way. Leprieur (in Ann. Sci. Nat., Bot., ser. 2, 2: 184–186. 1834) established the name with the spelling Stylochaeton and attributed neuter gender to it. He explicitly intended the name to allude, aptly, to an indusium around the style (i.e., the characteristic cupular perigon subtending each pistil) but gave the derivation of the second part of the compound as from "χητον", a word which, as explained by Nicolson & Mayo (l.c.), does not exist – certainly not in the intended meaning, and whose "eta" should anyway have been transliterated as "e" and not "ae". Given the clear intended original meaning, it should have been based on the masculine χιτων meaning "tunic", and transliterated as "chiton" (Nicolson & Mayo, l.c.). Schott (Aroideae: 10, t. 14. 1853; Gen. Aroid.: 68. 1858; Prodr. Syst. Aroid.: 344. 1860) corrected the spelling to Stylochiton but retained its neuter gender. Then, Engler (in Candolle & Candolle, Monogr. Phan. 2: 521. 1879) pointed out that both the spelling and gender of Leprieur's name were incorrect and used Stylochiton with masculine epithets. It remained widely used as Schott and then Engler had corrected it for well over a century until Nicolson & Mayo (l.c.) proposed masculine Stylochiton be formally conserved against "neuter" Stylochaeton, essentially to bind Engler's appropriate correction to both the spelling and gender. Apparently inexplicably, their proposal failed 6–5 against (Brummitt in Taxon 36: 736. 1987), with that report stating with peculiar diffidence that "[t]he name for this genus […] should apparently [sic] in future be given as Stylochaeton", but going on to communicate that the committee had nevertheless voted 6–5 in favour of it being treated as masculine even with the original spelling, though, with further diffidence, adding caveats that "[i]t is debatable […] whether this Committee has the authority to recommend a binding decision on this point [i.e., the gender], and secondly whether the required two-thirds majority (8 positive votes) should apply in this case or only in the conservation issue. [The provision to conserve a name with a particular gender appeared first in the Berlin Code (Greuter & al. in Regnum Veg. 131. 1994).] It is suggested [sic] that the 6–5 majority decision on the gender should be accepted." No reasoning was provided for the outcome and so it is not clear if that conservation proposal failed because some members of the Committee [for Spermatophyta] thought it was simply unnecessary (perhaps considering the case to be a straightforwardly correctable orthographic error), and/or whether and in what way some may have disagreed with its substance. At that time, the General Committee seemed only to deal with proposals recommended for acceptance by specialist committees (cf. Nicolson in Taxon 37: 440. 1988). Consequently, the matter has remained strictly unresolved. Nicolson & Mayo (l.c.) highlighted and itemised the almost entirely consistent use of masculine Stylochiton in taxonomic and floristic accounts from Engler onwards, but it is clear that instability has greatly increased after the Committee's response to their proposal. While floristic and taxonomic literature has largely but not exclusively (e.g., the generic monograph by Mayo & al., Gen. Araceae: 151. 1997, where Stylochaeton is treated as neuter) followed the diffident recommendations in Brummitt (l.c.) in using Stylochaeton with masculine epithets, other fields generally persist with Stylochiton. Searching Google Scholar on each spelling yields some 850 hits in a ratio of approximately 5:3 in favour of Stylochiton [approx. 4:3 when filtered post Brummitt (l.c.) and the same ratio when filtered for 21st Century only]. However, ING (https://naturalhistory2.si.edu/botany/ing/), IPNI (https://www.ipni.org/?q=stylochaeton), POWO (https://powo.science.kew.org) and the Naturalis Bioportal (https://bioportal.naturalis.nl/nl) (all accessed 7 Aug 2024), have adopted both the erroneous original spelling and neuter gender, thus following Brummitt (l.c.) on the orthography but not in the matter of gender. Other online databases and virtual herbaria (all accessed 7 Aug 2024), e.g., BM (https://data.nhm.ac.uk), GBIF (https://www.gbif.org/species/2871821), P (https://science.mnhn.fr/institution/mnhn/list?full_text=stylochaeton), and US (https://collections.nmnh.si.edu/search/botany/), treat Stylochaeton as masculine, while the gender is mixed at B (http://ww2.bgbm.org/herbarium/), BR (https://www.botanicalcollections.be/#/en/search/specimen) and JACQ (https://www.jacq.org/#database). Masculine Stylochiton is used at NY (https://sweetgum.nybg.org/science/vh/). Tropicos (https://www.tropicos.org/name/Search) and Global Plants (JSTOR; https://plants.jstor.org) have both spellings, mostly with masculine epithets. Two new species were described last year with neuter epithets in Stylochaeton (Struwig & al. in Phytotaxa 620: 1. 2023). Together, these instances highlight the ongoing want of a firm unambiguous determination or coalescence around a single consensual viewpoint. Based upon masculine Stylochiton being both etymologically correct and in somewhat wider modern use as well as much longer traditional use than Stylochaeton with either gender, we here propose again that masculine Stylochiton with that spelling be formally conserved. Guidelines for proposals such as this ask for counterargument. Given the extent of current instability in this instance, it could be said that any rational unambiguous determination on the orthography and gender of this generic name will be an improvement over the current shambles. One approach would be "originalist": to determine that Leprieur's neuter Stylochaeton should prevail simply because that is how it was established, regardless of its errors. The second available approach would be to enshrine as firm determinations the rather extensively ignored, unassertive suggestions in Brummitt (l.c.) of masculine Stylochaeton. The third, preferred, approach is to formally conserve the now one and a half centuries-old adoption of masculine Stylochiton as was proposed 40 years ago (Nicolson & Mayo, l.c.). Of these, the recommendation by the Committee for Spermatophyta in 1987 (Brummitt, l.c.) that the spelling be Stylochaeton and the gender be masculine was itself a linguistic error which has served only to compound rather than settle the issue. Nicolson & Mayo (l.c.) had pointed out that the ending, -ον [omicron nu], of the word Leprieur used as the basis for -chaeton, spurious though it was, signified neuter gender, and so that Committee's recommending the retention of the original spelling of the generic name while voting that it be treated as masculine was simply nonsensical from a linguistic point of view. The ending -ων [ōmega nu] from the corrected -chiton, however, is usually masculine and never correctly neuter (cf., for example, masculine Potamogeton). It can be said that, having been treated as masculine since 1879 (Engler, l.c.), masculine is the traditional gender to be retained (cf. Art. 62.1 of the Shenzhen Code, Turland & al. in Regnum Veg. 159. 2018). However, reverting to the original orthography effectively changes the derivation of the termination requiring a change in the gender – in this case reversion to neuter (cf. Art. 62.2). Choosing between the "originalist" option of etymologically and orthographically spurious neuter Stylochaeton and the long-ago corrected and long-used masculine Stylochiton appears straight-forward: Stylochiton has had far longer continuous majority use, and remains in majority use now. To formalise a reversion to Leprieur's neuter Stylochaeton would be the more disruptive course. The adoption of Stylochaeton by a number of taxonomists, but the ongoing use, regardless of the 40-year-old suggestions in Brummitt (l.c.), of Stylochiton by non-taxonomists, reflects the former's responsiveness and adaptability to recommended orthographic change, and therefore we can reasonably say that formally conserving Stylochiton will hardly traumatise the taxonomic community, but will provide welcome continuity for the non-taxonomic community whom we serve. In the event that this conservation proposal is deemed unnecessary, we request, given the context of decades of confusion and ambiguity imposed since the Committee's insufficiently decisive response to the previous proposal, an explicit determination that the name's orthography (and thence its gender) is to be corrected to masculine Stylochiton under Art. 60.1 of the Shenzhen Code, in order to finally bring stability to this matter.

Coastal vegetation will be the first areas to be directly affected by rising sea levels as a result of climate change. Thus, it is urgent to know and disseminate information about their plant diversity, especially those that are already known to be impacted by other threat factors. Here we present two new critically endangered Anthurium sect. Urospadix species from the restingas of Bahia, Brazil: A. bellissimum and A. itacarense. Descriptions, illustrations, photos in vivo, as well as discussion on the conservation status and related species are provided.

The two species of Montrichardia (Araceae) are perennial herbs of great ecological, economic, and ethnobotanical importance that form populations by clonal growth and sexual reproduction. Here, genetic diversity was studied within a drainage system distant from Amazonia. Five populations were sampled from the Rio Parnaíba Delta (northeast Brazil) and two outside it. The eight ISSR primers selected generated 342 marker bands. The non-Delta populations ( M. arborescens ) were grouped together by cluster analysis and Bayesian simulation but the Delta populations ( M. linifera ) were only grouped weakly. Ordination and Bayesian simulation grouped populations into three pairs along an east–west axis. All population pairs were significantly different (pairwise PhiPT , p  ≤ 0.001). Between-population variance (AMOVA, 39.9% variance, p  < 0.001) was much greater than between-species (12.2%, p  < 0.034), but within-population variance was greatest (48.0%). Within the Delta, geographical distance between populations did not predict genetic similarity, but relative within-population diversity appears to be influenced by habitat differences. There is genetic evidence, but relatively weak, for recognizing the Delta populations as M. linifera and the non-Delta ones as M. arborescens ; Paulino Neves (Maranhão) appears to be the easternmost record for this species. The strong between-population differences previously reported for M. linifera are corroborated.

The Checklist of the Vascular Plants of the Republic of Guinea (CVPRG) is a specimen-based, expert-validated knowledge product, which provides a concise synthesis and overview of current knowledge on 3901 vascular plant species documented from Guinea (Conakry), West Africa, including their accepted names and synonyms, as well as their distribution and status within Guinea (indigenous or introduced, endemic or not). The CVPRG is generated automatically from the Guinea Collections Database and the Guinea Names Backbone Database, both developed and maintained at the Royal Botanic Gardens, Kew, in collaboration with the staff of the National Herbarium of Guinea. A total of 3505 indigenous vascular plant species are reported of which 3328 are flowering plants (angiosperms); this represents a 26% increase in known indigenous angiosperms since the last floristic overview. Intended as a reference for scientists documenting the diversity and distribution of the Guinea flora, the CVPRG will also inform those seeking to safeguard the rich plant diversity of Guinea and the societal, ecological and economic benefits accruing from these biological resources.

Background and aims – The Cyperus margaritaceus-niveus complex is a group of ten tropical species from sub-Saharan Africa and Madagascar: C. karlschumannii, C. kibweanus, C. ledermannii, C. margaritaceus, C. niveus, C. nduru, C. obtusiflorus, C. somaliensis, C. sphaerocephalus, and C. tisserantii. They are characterised by a capitate head of white-yellow spikelets and modified culm bases and recent molecular analysis puts them in a distinct clade. The group lacks a modern taxonomic revision, and the taxa described in the Flora treatments of the past 50 years differ considerably in their circumscription. In this study, morphometric analyses are used to test species limits to establish more stable morphological delimitations of the taxa. Material and methods – An examination of 15 morphological characters on 489 herbarium specimens was carried out and the data was analysed using Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA) with cross-validation, and Classification and Regression Tree (CART) analysis. Cyperus kibweanus was not further considered due to lack of material. Key results – Both PCA and LDA showed varying degrees of overlap in the nine remaining taxa, with no single group clearly separating in multivariate space. However, cross-validation clearly showed C. margaritaceus as a distinct entity despite its overwhelming presence in the PCA. Both LDA and CART failed to separate C. niveus as a distinct group as its specimens were dispersed among the other groups. Differing results were obtained for other taxa depending on the type of analysis. Cyperus margaritaceus, C. nduru, and C. sphaerocephalus were divided into two groups by CART but re-examination of the specimens does not definitively support the idea that these infraspecific groups represent separate taxa. Conclusions – The results show that eight morphospecies are recognised by LDA and six morphospecies by CART. Characters used to separate the taxa in Flora treatments scored high loadings in the analysis showing their high taxonomic utility value. The methods used can be applied to resolving other complexes in the Cyperaceae.

PREMISE:Recent phylogenetic studies of the Araceae have confirmed the position of the duckweeds nested within the aroids, and the monophyly of a clade containing all the unisexual flowered aroids plus the bisexual-flowered Calla palustris. The main objective of the present study was to better resolve the deep phylogenetic relationships among the main lineages within the family, particularly the relationships between the eight currently recognized subfamilies. We also aimed to confirm the phylogenetic position of the enigmatic genus Calla in relation to the long-debated evolutionary transition between bisexual and unisexual flowers in the family.METHODS:Nuclear DNA sequence data were generated for 128 species across 111 genera (78%) of Araceae using target sequence capture and the Angiosperms 353 universal probe set.RESULTS:The phylogenomic data confirmed the monophyly of the eight Araceae subfamilies, but the phylogenetic position of subfamily Lasioideae remains uncertain. The genus Calla is included in subfamily Aroideae, which has also been expanded to include Zamioculcadoideae. The tribe Aglaonemateae is newly defined to include the genera Aglaonema and Boycea.CONCLUSIONS:Our results strongly suggest that new research on African genera (Callopsis, Nephthytis, and Anubias) and Calla will be important for understanding the early evolution of the Aroideae. Also of particular interest are the phylogenetic positions of the isolated genera Montrichardia, Zantedeschia, and Anchomanes, which remain only moderately supported here.

Natural populations of cajui (Anacardium occidentale L.) are ecologically and socioeconomically important for many people in Northeastern Brazil. This study focuses on the use and management of wild cashew in the communities Canarias, in Maranhao, and Labino and Barrinha, in Piaui. Semi-structured forms were applied to 88 participants. The Use Diversity (UDs) and Plant Part Value (PPV) indexes were calculated and a multivariate linear regression analysis was performed. Most (73%) the interviewees were women. Cajui was mainly used for food (UDs: 0.87), forage (0.08), medicinal preparations (0.03), and fuel (0.02). The hypocarp had the highest PPV (0.76). Cajui fruits are collected by groups, in the forest (50%), during the harvest season (July to October). Cajui has great socioeconomic importance for the communities studied and allow the continuity of the cultural identity associated with socio-biodiversity.

The species of classical taxonomy are examined with a view to their future role in integrative taxonomy. Taxonomic species are presented as the products of a cyclic workflow between taxonomists and biologists in general, and as the essential means to express the results of evolutionary biological research in a cognitive form which can be widely understood outside the systematics research community. In the first part, the procedures underlying the formation and structure of classical species taxon concepts are analysed and discussed, and this involves some passing reference to mental concepts as understood by cognitive psychologists. The second part considers the need for methodological advances in classical taxonomy in the form of computational modelling. It is argued that in order to accomplish this, species taxon concepts will need to be expressed as computable matrices in parallel to their conventional form, expanding their role in integrative taxonomy, facilitating the feedback from evolutionary biological research and potentially accelerating the update and modification of their delimitation as knowledge increases. The third part treats another, more immediate methodological issue: some kinds of data already produced by taxonomic revisions could be provided as standard online outputs but are not yet part of the canonical published format. The final part consists of a discussion of the gradually emerging global online framework of taxonomic species and its importance as a general reference system. A glossary of terms is provided.

In this floristic study, four species of Passiflora ( Passiflora cincinnata, P. foetida, P. misera, P. subrotunda ) were recorded in the coastal region of the Brazilian State of Piauí. The taxa occur in habitats with moist, muddy, sandy and stony substrates. The most prevalent species were P . foetida and P . subrotunda . An identification key is provided, together with descriptions of the species and data on their occurrence and distribution in the study region.

The Trichocentrum cepula complex comprises three species, T. caatingaense, T. cepula and T. sprucei, endemic to tropical forests east of the Andes in South America. The delimitation of these species has been diversely interpreted due to the extensive morphological variation in the complex. We applied an integrative approach to achieve a better understanding of these biological units, using geometric morphometrics, cytogenetic analysis (chromosome counts and CMA/DAPI banding) and molecular phylogenetics (ITS and rpl32-trnL). An initial morphometric analysis using the pre-identified specimens into three taxa suggested that T. sprucei is distinct from the other two, which show some overlap. A subsequent analysis of the labellum, including only T. caatingaense and T. cepula organized in six pseudo-populations, suggested the existence of four morphological groups. All analysed specimens presented 2n = 36 chromosomes, CMA+/DAPI− terminal bands and CMA−/DAPI+ pericentromeric bands, which varied in number across species, localities or even individuals from the same locality. The notable variation in DAPI+ pericentromeric bands may be related to transposable elements that could also be a factor influencing the wide morphological variation in the flowers. In the phylogenetic analysis, the specimens belonging to T. caatingaense formed a strongly supported clade sister to the rest, whereas the specimens belonging to T. cepula and T. sprucei emerged together, with their relationships tending to be determined by geographic proximity. The evidence we generated suggests that treating the Brazilian populations of this species complex under a single name, T. cepula, provides more taxonomic stability and utility, thus the necessary taxonomic changes are implemented.

Wild cashew Anacardium occidentale L., used locally for food and medicinals, occurs in coastal restinga vegetation in northeastern Brazil. Leaf and bark hydroethanolic extracts from four populations in Piauí state were studied for secondary metabolites, estimation of total phenolics and flavonoids (UV‐Vis spectrophotometry), identification of the selected phenolic compound gallic acid (HPLC), antioxidant (DPPH) assays and estimates of antibacterial activity (agar diffusion, MIC, MBC). Results varied between populations and between leaf and bark. Alkaloids, flavonoids, organic acids, phenolics, reducing sugars, saponins and triterpenoids were observed. Total phenolics and flavonoids levels exceeded those of domesticated cashew (phenolics mg GAE g‐1: leaves 235.6–521.6, bark 430.5–546.3; flavonoids mg QE g‐1: leaves 22.1–30.8, bark 22.3–27.1). Presence of gallic acid was confirmed. Antioxidant IC50 values (DPPH inhibition) ranged from 45.81 to 88.53 µg/mL. Gram‐positive bacterial growth was inhibited (MIC 62.5–250 [‐500] µg/mL in Staphylococcus aureus [sensitive and MRSA strains], S. epidermidis, S. saprophyticus; MIC 500–2000 µg/mL in Streptococcus mutans). Bactericidal activity was observed in two populations (MBC 500–1000 µg/mL). The results corroborate studies of cerrado forms indicating that wild populations are richer in bioactive compounds than domesticated forms and highlight the need to conserve their habitats.

AbstractA new theoretical model of phyllotactic patterns is presented in this book, based on the geometry of two oppositely twisted spirals or helices. Many of the models previously proposed to explain observations of phyllotactic patterns are thus explained mathematically. The book is abundantly illustrated with computer graphics and supplemented by hyperlinks to many more images and video animations avaiable online, showing the way phyllotactic patterns vary with growth and change in the geometry of the plant axis.

Anthurium sterilispadix (previously A. bromelicola subsp. bahiense ) is recognized as a new species, closely related to A. bromelicola and representing a third species of Araceae exhibiting commensalism with Bromeliaceae. The two species share the same highly unusual slender twining habit but differ markedly in inflorescence morphology, each exhibiting characteristics unique in the genus and suggesting divergent pollination biology. In A. sterilispadix , the spathe spreads widely without differentiation into tube and lamina, the lamina is smooth and pink adaxially showing colour changes according to the stage of anthesis and the greater part of the narrowly tapering pale yellow spadix consists of modified sterile flowers which appear to be osmophoric. In A. bromelicola the spathe has tube-blade dimorphism, is adaxially deep purple and conspicuously ribbed, the spadix is relatively stout and the flowers have black-purple tepals and are all fertile. Anatomical study of leaves and inflorescences of both species revealed unusual features for the genus, such as the presence of vascularized ribs in the A. bromelicola spathe, and sterile osmophoric regions in the A. sterilispadix spadix; these novel characters are documented and discussed for the first time here. Nomenclature, taxonomic descriptions, images, geographical and ecological notes and an identification key are presented. Both species are endemic to the Brazilian Atlantic Forest region and are estimated to be endangered.

Abstract The present study is a taxonomic treatment of Bignoniaceae from the four municipalities of the coastal region of Piauí state (Cajueiro da Praia, Ilha Grande, Luís Correia, Parnaíba) in Northeast Brazil, based on morphological study of newly collected and existing herbarium material. The study recorded 26 species in 12 genera: Adenocalymma, Anemopaegma, Bignonia, Cuspidaria, Dolichandra, Fridericia, Handroanthus, Lundia, Neojobertia, Pleonotoma, Stizophyllum and Tanaecium. Apart from Handroanthus impetiginosus, which belongs to tribe Tecomeae, all other species belong to tribe Bignonieae. Five species (Adenocalymma apparicianum, A. pedunculatum, Anemopaegma heringeri, A. prostratum, Dolichandra hispida) are new records for the state of Piauí, 15 species are endemic to Brazil, and one has “Vulnerable” conservation status. The results emphasize the importance of taxonomic studies for knowledge of biodiversity and threats to native species, and reinforce the importance of conserving the region’s flora. Species descriptions, illustrations, identification keys and information on geographic distribution and habitat are provided.