Cactaceae es un grupo diverso en las regiones áridas y semiáridas de México. La taxonomía de Cactaceae se ha reconfigurado en años recientes. En este trabajo se actualiza el listado de Cactaceae para Jalisco y analiza su distribución geográfica. Se construyó una base de datos con 1,894 registros. Se analizó la riqueza taxonómica y diversidad filogenética por diferentes criterios geográficos. El estudio reconoció 98 especies y 25 géneros nativos. Los géneros más diversos fueron Mammillaria y Opuntia. Se identificaron 6 zonas con alta riqueza taxonómica. Las celdas más diversas se ubicaron al noreste del estado, en los límites de los municipios Lagos de Moreno y Ojuelos, en la provincia Desierto Chihuahuense. En esta región, las condiciones de aridez son ideales para el establecimiento y diversificación de la familia. Las Tierras Bajas del Pacífico y Desierto Chihuahuense presentaron 59 y 56 especies, respectivamente. El bosque tropical caducifolio incluyó 86 especies. La región sur del estado con una marcada estación seca mostró una importante diversidad. Jalisco se ubicó en la octava posición de riqueza de cactáceas. Los resultados revelan la necesidad de complementariedad de diferentes regiones para lograr la conservación de este grupo de plantas.

Acanthocereus is a monophyletic group comprising 16 species with contrasting vegetative morphology, the greatest diversity is found in the Pacific Lowlands in Mexico. Our prior taxonomic studies on the genus revealed a challenge in delimiting A. rosei, owing to its disjunct distribution and incomplete understanding of morphological variation. Also, during field work in the states of Jalisco and Nayarit, we collected specimens of Acanthocereus with a unique combination of characters inconsistent with previously described taxa. We conducted a phylogenetic analysis using three cpDNA sequences and performed a morphological comparison of disjunct populations of A. rosei in Jalisco and Sinaloa, the atypical Acanthocereus specimens, and other sympatric and similar species from western Mexico. Our results identified the disjunct populations of A. rosei, as well as Acanthocereus sp. as independent lineages. Morphological comparison further supported their divergence by a unique combination of characters. Based on this evidence, we propose a description of two new species two new species of Acanthocereus from western Mexico.

Background: Recent floristic lists indicate that the Mexican Bajío is a diverse area in terms of the number of species and endemism of Cactaceae. Questions and/or Hypotheses: 1) How many taxa are distributed in the Bajío and adjacent regions? 2) What are the vegetation types and biogeographic provinces with the greatest species richness? 3) What are the areas with the highest level of endemism? Studied species: Cactaceae family. Study site and dates: Bajío region (Guanajuato, Querétaro and northern part of Michoacán), México, which was visited between 2014 and 2022. Methods: With the use of herbarium, field collections and iNaturalist/iNaturalistMX records, a database was constructed from which species richness, weighted endemism and weighted endemism corrected by one-third degree cells were estimated. Results: Thirty genera and 125 species of cacti are reported. Xerophilous scrub is the type of vegetation that hosts the greatest number of species. The Chihuahuan Desert is the province with the highest level of richness. The cells with the highest richness and weighted endemism are found between the provinces of the Chihuahuan Desert and the Sierra Madre Oriental. In contrast, there is a decrease toward the Trans-Mexican Volcanic Belt. Conclusions: Of the three biogeographic provinces that converge in the Bajío region —the Trans-Mexican Volcanic Belt, the Chihuahuan Desert, and the Sierra Madre Oriental— the largest number of endemic species is found on the borders between the latter two, likely because this region was a climatic refuge during the Pleistocene.

Mammillaria ser. Stylothelae is a well-recognized group in southern Chihuahuan Desert. Some members of this series have been regarded as highly polymorphic species. Recent analyses showed that some populations of those species complex can be accepted as independent species. In this study, we analyzed and compared quantitative and qualitative characters to identify a putative new species. We compared it with close geographical and morphological species of the series. Based on our findings, we described a new endemic species of M. ser. Stylothelae from Querétaro, Mexico. The new taxon is distinctive by the globose growth form, small size, the number of central and radial spines, presence of fibrous roots, naked axils and non-arillate seeds. Additionally, we provided information about habitat and the preliminary status of conservation of the new taxon.

Pholisma belongs to the family Lennoaceae, classified as obligate root holoparasites. Most existing studies are limited to addressing only P. arenarium. In this study, morphoanatomical and developmental aspects of flowers of the three species comprising Pholisma are described using histological embedding techniques in Paraplast and LR- White and observations by light microscopy and scanning electron microscopy. Similarities found in the three species include the presence of trichomes on the sepals, each carpel folding independently. Each carpel has transmitting tissue, and an empty cavity is distinguished in the centre of the style. The stigma is crateriform and of the wet type. Sporogenesis, gametogenesis, and floral development follow a similar pattern in the three species. Differences among species include the position of the stamens, pollen morphology, type of inflorescence, and colour of flowers and inflorescences. In P. arenarium, the stamens are located below the stigma height, and the pollen is tetracolporate and psilate; in P. sonorae, the stamens are at the same height as the stigma, and the pollen is tricolporate and reticulate; and in P. culiacana, the stamens are above the stigma height, and the pollen is tricolporate and psilate. The inflorescences in both P. arenarium and P. sonorae are cymes; the corolla colour is white with purple lines extending from the limb to the corolla tube. In contrast, the inflorescence in P. culiacana is a capitulum type, and the corolla colour is white with pink margins. The characters found in the three species of Pholisma are compared with some genera comprising the family Ehretiaceae.

Jaltomata Schltdl. is the sister genus of Solanum L., and maintains important wild traits, as well as great potential for application in plant breeding issues by conserving a relevant genetic pool. In Mexico, the taxonomic ambiguity in the group has limited their knowledge and correct management. Plant morphology is essential to detect diagnostic characters for species delimitation. Leaves are highly variable organs and fundamental in taxonomy. Here, we evaluate whether leaf characters allow the recognition of Mexican species of Jaltomata. We analysed 11 possible diagnostic characters, five quantitative and six qualitative, extracted from taxonomic literature and leaf architecture manuals. The data were analysed using a linear discriminant analysis, hierarchical cluster analysis, and permutational multivariate analysis of variance. Our results show significant segregations in Jaltomata grandiflora (B.L.Rob. Greenm.) D’Arcy, Mione Tilton Davis, J. bohsiana Mione D.M.Spooner, and J. chihuahuensis (Bitter) Mione Bye, while the characters evaluated only allowed a partial delimitation between J. procumbens (Cav.) J.L.Gentry and J. repandidentata (Dunal) Hunz. Additionally, J. darcyana Mione, and one morphotype (Bohsiana1 group) were detected. The margin, the abundance of pubescence, the pubescence in the secondary veins, the shape and angle of the apex, as well as the leaf length × width ratio turned out to be the characters with the highest discriminate value. We provide the first foliar key for Mexican Jaltomata species and conclude that leaf morphological traits are an important criterion to consider and they should be included in the taxonomic keys of the genus.

Antecedentes y Objetivos: Mammillaria es uno de los géneros más representativos de Cactaceae. En la región del Bajío, México, se distribuyen aproximadamente 70 especies y nueve subespecies, de las cuales siete especies y una subespecie corresponden a M. ser. Leucocephalae. En exploraciones recientes se encontraron individuos cuya morfología no concuerda con las especies descritas en los tratamientos taxonómicos actualizados. El objetivo de este trabajo es caracterizar y describir una nueva especie, con base en evidencia morfológica y medioambiental. Métodos: Se realizó trabajo de campo en junio de 2022. Se analizaron mediante el Análisis Canónico Discriminante (ACD) siete caracteres morfológicos. Además, se calcularon los residuos de Pearson para dos variables medioambientales y la significancia se estimó con una prueba de bondad de ajuste chi-cuadrada. El área de ocupación y la extensión de ocurrencia se calcularon para asignar la categoría de conservación según los criterios y categorías de la Lista Roja de la IUCN. Resultados clave: Se describe e ilustra a Mammillaria ariasii, similar a Mammillaria hahniana, de la cual difiere por el número de espinas radiales, la longitud de la espina central inferior y el color de los tépalos internos del perianto. La presencia de cristales extracelulares confirma su inclusión en M. ser. Leucocephalae. Mammillaria ariasii se caracteriza por habitar en suelos kastanozems háplico y relieves volcánicos en un área de ocupación aproximada de 28 km2 y de extensión de ocurrencia de 345 km2. Se proporciona una clave de identificación en donde se compara con otros miembros de Mammillaria ser. Leucocephalae. Conclusiones: Mammillaria ariasii es una nueva especie endémica del Bajío. De acuerdo con nuestros resultados debe ser considerada como especie en peligro (EN). Si bien es localmente abundante, debe tenerse en cuenta la erosión y la ganadería como factores potenciales de riesgo.

Background: The chloroplast genomes of Cactaceae exhibit boundary modifications in the inverted repeat regions (IRs), gene inversions, and deletions. Among nine Mammillaria species, three distinct chloroplast structures have been identified, although not all of these correspond to the morphology-based classification of the genus. Question: Is there a distinct chloroplast genome structure in the species of Mammillaria series Stylothelae? Studied species: Mammillaria bocasana and M. erythrosperma. Study site and dates: Mexico from 2019 to 2023. Methods: Chloroplast DNA was sequenced, and chloroplast genomes were de novo assembled using the Fast-Plast program. Complete plastome sequences were annotated and verified. The sequences were aligned in MAUVE program to detect possible structural changes. A maximum likelihood phylogeny was executed to evaluate the relationships of the studied species. Results: The plastomes ranged from 107,368 bp in Mammillaria bocasana to 108,069 bp in M. erythrosperma. Both presented a quadripartite structure and contained 108 genes. The IRs were ~ 1,600 bp long and included the genes rpl2, rpl23 (pseudo), and trnI-CAU. MAUVE identified a ~ 21 kb inversion in the large single copy containing a block of genes related to photosynthesis. The phylogenetic analysis placed both species in a single clade separated from the other species within Mammillaria subg. Mammillaria. Conclusions: The studied species of Mammillaria series Stylothelae exhibited a different and synapomorphic chloroplast genome structure. Other Mammillaria chloroplast genome structures have evolved independently in different lineages.

Floral scents play a pivotal role during the pollination of certain plant species by enhancing floral attractiveness and facilitating pollination. Particularly in holoparasitic plants, floral scent serves as a crucial recognition signal between flowers and pollinators, given that flowers or inflorescences are distinct features that stand out from the hosts and the substrate. However, information regarding floral scents in the Lennoaceae family remains scarce. In this study, we identified floral scents emitted as chemical signals for pollinator attraction in the four species included in Lennoaceae. We conducted an in-situ analysis and comparison of the chemical composition of floral scents of Lennoaceae species in Mexico using the dynamic headspace method, followed by chemical analysis via GC-MS. Our research has unveiled the chemical diversity of floral scents within the Lennoaceae family, revealing the dominance of aliphatic compounds, terpenes (mono- and sesqui-), and benzenoids. This study marks the first investigation into floral scent in Lennoaceae, representing an initial step towards unraveling the relationship between parasitic plants and their floral visitors through floral scents.

Biotic pollination is typically a mutualism between plants and their pollinators, where each partner receives a benefit. However, plants can resort to various reproductive strategies to attract pollinators. Within angiosperms, a group of plants known as endoparasites is comprised of only flowers or inflorescences. These plants exhibit various reproductive strategies, such as different sexual systems and attractants, and most are dependent on animals for pollination. In the endoparasitic plants of the family Apodanthaceae, unisexual flowers are predominant, resulting in dependence on pollinators. Pilostyles thurberi is characterized by small flowers, but limited information exists about its reproductive strategies. This study investigated various reproductive aspects of P. thurberi. We described and compared its hosts, sexual flower arrangement, floral concentration, rewards, and reproductive success in different populations. Furthermore, we determined whether the floral display operates as an attractant by monitoring pollinators for two years. Our results revealed that P. thurberi has unisexual flowers with male, female, and mixed sex arrangements. Bees and wasps are the effective pollinators and are attracted by the floral display independently of flower sex. This study was the first to record the production of small amounts of crystallized nectar by the nectary disk of both floral sexes. Moreover, the findings were compared with those of other endoparasitic plants, such as Cytinaceae, Mitrastemonaceae, Rafflesiaceae, and other Apodanthaceae. It is necessary to continue studying the plant-pollinator interactions and reproductive strategies of parasitic plants such as Apodanthaceae, since not much evidence on how they reproduce and survive in the wild exists.

A new species of Mammillaria ser. Stylothelae is described and illustrated. Mammillaria monochrysacantha is distinguished from other species of the series by having a globose stem with fibrous roots, one single golden yellow hooked central spine, 28–32 tortuous hair-like radial spines, flowers with lanceolate pale yellow tepals, and non-arilloid seeds. We provided a comparison with other morphologically close and sympatric species of Mammillaria. The new species is endemic from the Sierra Gorda, Guanajuato, Mexico. We included data about its habitat and the status of conservation. Additionally, we integrated an identification key for M. ser. Stylothelae from Guanajuato, San Luis Potosí, and Querétaro, Mexico.

Otatea is a Neotropical woody bamboo genus with thirteen described species. It is distributed from Mexico to Central America and northeastern Colombia. In Mexico, the archaeological evidence suggests that the culms of Otatea have been used for centuries by some ethnic groups. It is important to explore morphological and anatomical characters for species identification in woody bamboos as consequence of its monocarpic nature. Most studies on culm anatomy are centered on commercially used species describing their physical and mechanical properties. The aim of this work was to find culm anatomical characters with taxonomic value. To perform this, we collected internode samples from adult plants at mid culm of 15 specimens that represent 10 described species and two putative new species of Otatea. Our results include descriptions of culm anatomy at a cross section accompanied with images that detail all the structures measured and described. Additionally, we elaborate a key based on anatomical characters. This contribution is the first to explore culm anatomy of the genus Otatea in search for characters with taxonomic value, providing useful evidence for species identification, including samples from archaeological sites.

We describe a new endemic densely spined Mammillaria from San Luis Potosi, Mexico. The new species, named M. morentiniana, is distinctive by the presence of a globose to shortly cylindric stem with several glabrous, reddish central spines, radial spines that protrude from the plant like white needle-bristles, and small flowers with pale yellow, lanceolate tepals. We compare it with similar and sympatric species of M. ser. Stylothelae. We include data about habitat and the preliminary status of conservation of the new taxon.

Background: The Mammillaria series Stylothelae (Cactaceae) includes 16 taxa distributed mostly among the limits of the Chihuahuan Desert (CD) with the Sierra Madre Oriental and the Transmexican Volcanic Belt (TVB). In Jalisco, four pink flowered species occur at the southwestern end of the CD where it meets the TVB. The boundaries and recognition of three species related with M. fittkaui (M. fittkaui complex) are debatable. Question: Should the taxa of the Mammillaria fittkaui species complex be considered as species? Studied species: Four pink flowered Mammillaria series Stylothelae (M. fittkaui species complex) and M. zeilmanniana as comparative species. Study site: Western Mexico. Methods: Six morphological characters were sampled in specimens from the type locations of three pink flowered species, one locality of Mammillaria sp., and M. zeilmanniana. We used a permutational multivariate analysis of variance on six characters of each of the groups and a discriminant analysis to evaluate the morphological variation among species and to determine the correct classification of each individual. Results: The analyses identified four well defined morphological groups with statistical significance within the Mammillaria fittkaui complex. We recognized M. fittkaui, M. limonensis, and M. manana as species and here describe M. arreolae as a new species from Jalisco. Conclusions: In Cactaceae, morphometry has been useful to establish species boundaries. The Mammillaria fittkaui complex includes four species. Mammillaria arreolae differs from the other species by the shorter tubercles, flowers, and fruits. In addition, it develops more than one hooked central spine per areole.

The genus Coryphantha includes plants with globose to cylindrical stems bearing furrowed tubercles, flowers arising at the apex, and seeds with flattened testa cells. Coryphantha is the second richest genus in the tribe Cacteae. Nevertheless, the genus lacks a phylogenetic framework. The limits of Coryphantha with its sister genus Escobaria and the infrageneric classification of Coryphantha have not been evaluated in a phylogenetic study. In this study we analyzed five chloroplast regions (matK, rbcL, psbA-trnH, rpl16, and trnL-F) using Bayesian phylogenetic analysis. We included 44 species of Coryphantha and 43 additional species of the tribe Cacteae. Our results support the monophyly of Coryphantha by excluding C.macromeris. Escobaria + Pelecyphora + C.macromeris are corroborated as the sister group of Coryphantha. Within Coryphantha our phylogenetic analyses recovered two main clades containing seven subclades, and we propose to recognize those as two subgenera and seven sections, respectively. Also, a new delimitation of Pelecyphora including C.macromeris and all species previously included in Escobaria is proposed. To accommodate this new delimitation 25 new combinations are proposed. The seven subclades recovered within Coryphantha are morphologically and geographically congruent, and partially agree with the traditional classification of this genus.

Background: Aporocactus is an epiphytic or saxicolous genus that is endemic to Mexico and has a distribution restricted to cloud forests and pine-oak forests. As with many cacti, Aporocactus presents taxonomic conflicts, especially regarding species delimitation, since five species in this genus have been described and accepted by some authors, while others accept only two species. Questions: How many species comprise Aporocactus? What are their relationships? Do these species show differences in their climatic preferences? Studied species: The five putative species in Aporocactus were investigated. Study site and dates: This study was conducted in 2015 and 2016. The collection sites were in Hidalgo, Puebla, Querétaro, Veracruz, and Oaxaca states, Mexico. Methods: In this study, phylogenetic analyses were performed using chloroplast DNA markers from different Aporocactus populations and related genera, and ecological niche modeling techniques were also employed. Results: The phylogenetic analyses indicated that Aporocactus is composed of only two species: A. flagelliformis and A. martianus . Additionally, the phylogenetic analyses corroborated that Aporocactus is an early diverging group related to Weberocereus and Selenicereus . Finally, niche modeling and niche identity testing indicated that the niches of the two species of Aporocactus are significantly differentiated and niches are more different than would be expected by chance. Conclusions: Despite being a genus with only two species, Aporocactus represents a useful model for investigating such topics as the ecology of pollination, genetic populations, and flower development to characterize the evolution of these specialized cacti.

Stenocactus × irregularis , a new hybrid from the Bajío region of Mexico, is described and illustrated. The hybrid is proposed based on morphometric analyses of the hybrid and parental taxa. The number of ribs and the presence of incomplete ribs distinguish the new nothospecies from the parental species. In addition, we provide an updated identification key of the species of Stenocactus distributed in the Bajío region.

The genus Peniocereus contains distinctive cacti with slender stems and thickened roots. The phylogenetic relationship of Peniocereus to other members of the subtribe Pachycereinae is unresolved, and a sister group for the genus has not been suggested in previous molecular phylogenies. Therefore, this study aims to corroborate the monophyly of Peniocereus, to determine the relationships within the genus, to clarify their relationship with Nyctocereus, and to reconstruct the ancestral states for eight morphological characters and the areas of distribution. Five chloroplast markers (rpl16, petL-psbE, psbA-trnH, trnL-trnF, and rpl32-trnL) and a broad outgroup represented by all genera of the subtribes Pachycereinae and Echinocereinae were used in phylogenetic analyses. The results strongly supported the monophyly of Peniocereus, which comprises P. greggii, P. johnstonii, P. lazaro-cardenasii, P. marianus, P. striatus, P. viperinus, and P. zopilotensis. The genus was sister to the Pachycereus group, which comprises Carnegiea, Lophocereus, Marshallocereus, Nyctocereus, and Pachycereus (including Backebergia and Pterocereus). The scandent branches, slender stems, and papillose epidermis are ancestral characters to Peniocereus. A complex region including the Pacific Lowlands, the Balsas Basin, and the Sonoran Desert was inferred as the ancestral area for the genus. This work provides the most comprehensive phylogeny of the subtribe Pachycereinae.

This data paper presents a largely phylogeny-based online taxonomic backbone for the Cactaceae compiled from literature and online sources using the tools of the EDIT Platform for Cybertaxonomy. The data will form a contribution of the Caryophyllales Network for the World Flora Online and serve as the base for further integration of research results from the systematic research community. The final aim is to treat all effectively published scientific names in the family. The checklist includes 150 accepted genera, 1851 accepted species, 91 hybrids, 746 infraspecific taxa (458 heterotypic, 288 with autonyms), 17,932 synonyms of accepted taxa, 16 definitely excluded names, 389 names of uncertain application, 672 unresolved names and 454 names belonging to (probably artificial) named hybrids, totalling 22,275 names. The process of compiling this database is described and further editorial rules for the compilation of the taxonomic backbone for the Caryophyllales Network are proposed. A checklist depicting the current state of the taxonomic backbone is provided as supplemental material. All results are also available online on the website of the Caryophyllales Network and will be constantly updated and expanded in the future.