This is the first phylogenetic analysis of the Megamexican Bromeliaceae genus Hechtia and includes 82.6 % of the known taxa. We used plastid (ycf1, rpl32-trnL intergenic spacer), and nuclear (PRK) DNA regions, as well as morphological characters. We generated 244 new sequences for a total of 62 taxa (including 12 species of the outgroup). Results of combined data using parsimony and Bayesian inference reveal the monophyly of Hechtia, as well as identify five well supported clades: (1) a clade (H. tillandsioides complex) as the sister group to the rest of Hechtia; (2) a clade including the species of the H. guatemalensis complex, distributed in Southern Megamexico; the remaining taxa of the genus are retained in a clade which consists of three well-supported clades; (3) the H. glomerata complex distributed in the Gulf of Mexico drainage; (4) a clade of two species (H. deceptrix and H. epigyna) that share an inferior ovary and are distributed north of the Tehuantepec Isthmus in the Sierra Madre Oriental; and (5) an internally poorly resolved clade with the remaining species containing several well-supported, geographically restricted clades. At this time it is uncertain what part of Megamexico was first invaded by the ancestor of Hechtia. Regardless, it becomes clear that from the original point of invasion in what is now Megamexico, it radiated into restricted geographical realms with secondary radiations occurring within them, which resulted in some recurrent particular evolutionary trends most likely associated with the invasion of dry, highly seasonal climates, or cooler areas subject to occasional frosts. Lateral inflorescences and flower morphology suggesting pollination syndromes other than melittophily (psychophily/trochilophily) have evolved more than once in Hechtia.

Puya, a large genus mostly from South America, has been taxonomically divided into two subgenera: Puyopsis and Puya. The latter includes only eight species distributed mainly in Chile, extending to Argentina, Bolivia, and Peru. The species of subgenus Puya are recognized by the presence of a sterile apex of the inflorescence branches, whereas those of subgenus Puyopsis have fertile flowers all along the branches. The objectives of this article were to determine whether this diagnostic character was synapomorphic for subgenus Puya, and to explore the relationships between its species. Parsimony analyses were performed for 43 taxa and 93 morphological characters, 87 of which were discrete and six continuous. In the analysis that included all characters, a single most parsimonious tree was found that supported subgenus Puya by two synapomorphic character states, including the diagnostic character of a sterile inflorescence branch apex and a blooming pattern in which flowers open gradually from base to apex. The trees were better supported when the continuous characters were included. Further studies are suggested to resolve the infrageneric classification of Puya and the relationships of the species belonging to subgenus Puya.

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Galphimia glauca is a plant that is endemic to Mexico and has been commonly used since pre-Hispanic times to treat various illnesses, including central nervous system disorders and inflammation. The first studies investigating a natural population of G . glauca in Mexico showed that the plant has anxiolytic and sedative activities in mice and humans. The plant’s bioactive compounds were isolated and identified, and they belong to a family of nor -secofriedelanes called galphimines. The integration of DNA barcoding and thin-layer chromatography analysis was performed to clarify whether the botanical classification of the populations in the study, which were collected in different regions of Mexico, as G . glauca was correct or if the populations consist of more than one species of the genus Galphimia . We employed six DNA barcodes ( matK , rbcL , rpoC1 , psbA-trnH , ITS1 and ITS2 ) that were analyzed individually and in combination and then compared each other, to indicate differences among the studied populations. In the phylogenetic analysis, ITS1 and ITS2 markers as well as the combination of all DNA regions were the most efficient for discriminating the population studied. The thin-layer chromatography analysis exhibited four principal chemical profiles, one of which corresponded to the populations that produced galphimines. DNA barcoding was consistent and enabled us to differentiate the populations that produce galphimines from those that do not. The results of this investigation suggest that the studied populations belong to at least four different species of the genus Galphimia . The phylogenetic analysis and the thin-layer chromatography chemical profiles were convenient tools for establishing a strong relationship between the genotype and phenotype of the studied populations and could be used for quality control purposes to prepare herbal medicines from plants of the genus Galphimia .

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Bakerantha is one of the three genera of subfamily Hechtioideae (Bromeliaceae). This genus was reestablished recently, and it currently contains four species (B. caerulea, B. lundelliorum, B. purpusii, and B. tillandsioides), which are distributed throughout the central region of Mexico. Bakerantha tillandsioides has the widest geographical distribution of the four species, and some populations currently referred to it do not match the species description. In this study, we used extensive sampling (81 accessions) of four plastid regions (matK, rpl32-trnL, rps16-trnK, and ycf1) and the nuclear PRK gene to reconstruct the phylogenetic relationships and delimit the species boundaries in Bakerantha. Our results confirm the monophyly of Bakerantha, and the species delimitation analysis supports five evolutionary lineages within Bakerantha, showing that B. tillandsioides is nonmonophyletic as currently circumscribed. Diagnostic characters and coherent geographical distributions support the five lineages. On the basis of our results, we describe and illustrate B. hidalguense as a new species and provide evidence that B. caerulea is morphologically and ecologically different from B. tillandsioides, with which it has been confused in the past. Additionally, we provide a morphological key to the Bakerantha species.

Individuals of Aechmea bracteata show inflorescences with red scape bracts and odourless, yellow, tubular diurnal flowers, with closely arranged sexual organs, producing a large amount of fruits. In order to investigate the reproductive system of this species, a suite of characters was assessed: phenology, floral morphology and biology, nectar production dynamics, and fruit and seed production and germination, as a result of controlled pollination crosses. The study was conducted during two flowering seasons in wild populations in Yucatán, Mexico. Results suggest an annual flowering pattern with one flowering peak; flowers were diurnal, showing partial dichogamy (protandry)-herkogamy, anthers and stigma become mature before floral aperture, which could lead to self-pollination, nectar is produced during anthesis, varying in volume and total sugar concentration during the day; fruits and seeds were produced in all experimental crosses (cross-pollination, obligated cross-pollination, assisted and unassisted selfing, geitonogamy and apomixis), as well as high percentage seed germination. Several species of Aechmea are reportedly self-compatible and autogamous, as suggested by results of selfing and non-assisted selfing crosses, but these results are negated by the presence of apomixis, indicating that the species is apomictic. This is the first report of this breeding system for subgenus Aechmea and the sixth for Bromeliaceae. Polyembryony is here suggested for the first time in this genus and family based on the fact that more seeds were recorded that expected based on ovule numbers. Finally, when performing experimental crosses, estimating reproductive success based on number of seeds is a better approach than number of fruits, due to the effect of pseudogamy.