This paper highlights the most unique characteristics of Araceae: their high species diversity, high habit diversity, high rates of endemism, and high rates of new species discovery. Also discussed is the origin of the family in the Early Cretaceous period and its modern-day worldwide distribution, which shows high generic diversity in Asia and high species diversity in South America. The last 40 years have shown dramatic increases in the number of species known for most of the Neotropical genera but with most of the growth coming from Central America. The development of computerized determination keys has led to the realization that many more species are likely to be new to science. This study also recommends future directions and localities or regions where most aroid research should be concentrated.

We present an overview of the diversity, distribution, and conservation status of all 54 taxa of Araceae that are currently known from the state of Veracruz, Mexico. We provide a reference list that gives information about overall distribution, endemism, and occurrence in Mexican states and administrative regions/municipalities of Veracruz. For this latter state, we also provide information on life form, elevational range, habitat, uses, and distinguishing characters useful for species identification. We performed an assessment of conservation status at the regional and global level for 51 and three taxa, respectively, considering International Union for Conservation of Nature (IUCN) Red List Categories and Criteria. About 80% of aroid taxa from Veracruz belong to a threatened category, mainly because of the continued loss and fragmentation of their natural habitats caused by the lack of protected areas that include tropical humid and humid montane forests.

The subfamily Monsteroideae (Araceae) is the third richest clade in the family, with ca. 369 described species and ca. 700 estimated. It comprises mostly hemiepiphytic or epiphytic plants restricted to the tropics, with three intercontinental disjunctions. Using a dataset representing all 12 genera in Monsteroideae (126 taxa), and five plastid and two nuclear markers, we studied the systematics and historical biogeography of the group. We found high support for the monophyly of the three major clades (Spathiphylleae sister to Heteropsis Kunth and Rhaphidophora Hassk. clades), and for six of the genera within Monsteroideae. However, we found low rates of variation in the DNA sequences used and a lack of molecular markers suitable for species-level phylogenies in the group. We also performed ancestral state reconstruction of some morphological characters traditionally used for genera delimitation. Only seed shape and size, number of seeds, number of locules, and presence of endosperm showed utility in the classification of genera in Monsteroideae. We estimated ancestral ranges using a dispersal-extinction-cladogenesis model as implemented in the R package BioGeoBEARS and found evidence for a Gondwanan origin of the clade. One tropical disjunction (Monstera Adans. sister to Amydrium Schott–Epipremnum Schott) was found to be the product of a previous Boreotropical distribution. Two other disjunctions are more recent and likely due to long-distance dispersal: Spathiphyllum Schott (with Holochlamys Engl. nested within) represents a dispersal from South America to the Pacific Islands in Southeast Asia, and Rhaphidophora represents a dispersal from Asia to Africa. Future studies based on stronger phylogenetic reconstructions and complete morphological datasets are needed to explore the details of speciation and migration within and among areas in Asia.

The origin of Neotropical species diversity is strongly associated with the geological history of South America. Since the Miocene, a number of species radiations across different Neotropical lineages coincided with the rise of the Andes and the formation of the Isthmus of Panama. The species-rich genus Philodendron Schott (Araceae) is widely distributed across Neotropical rainforests, originating in the Late Oligocene and diversifying more intensely from the Miocene onward. It is likely that its diversification process and distribution patterns are associated with recent geological changes in the Americas. To test this hypothesis, we sampled the species diversity of Philodendron across its entire geographic range and used a combination of three non-coding plastid regions (petD, rpl16, and trnK/matK) to obtain a comprehensive time-calibrated phylogeny. We then inferred geographic range evolution and explored the impact of the Andean orogeny on speciation, extinction, and dispersal. The genus Philodendron originated ∼29 million years ago (mya) and experienced the earliest diversification events ∼25 mya in the Pan-Amazonian rainforests. From the Middle Miocene onward, multiple geographic range expansion events occurred from Amazonia to southeast Brazil and to the area which would become the Chocó and the northern Andes. From the Pliocene onward, Philodendron reached Central America and the Caribbean islands, and Andean lineages recolonized and diversified in Amazonia. In Philodendron, higher diversification rates are found in the adjacent lowland rainforests of the northern Andes compared with other regions in the Neotropics, demonstrating a potential indirect impact of the Andean uplift on species radiations in lowland regions.

This study presents an evaluation of the currently accepted sectional classification of the genus Anthurium Schott (Araceae) in light of a recently published molecular phylogeny for the group. In general, disagreements between these two occur because many diagnostic morphological characters used in the sectional classification turned out to be highly homoplasious within Anthurium, with multiple independent gains or losses of seemingly similar morphologies in distantly related clades. A new sectional classification of Anthurium that more accurately represents species relationships and the evolutionary history of the genus is much needed, and here we propose the first steps toward it. Results from this study suggest that out of the 18 sections and two series recognized in Anthurium, only seven of these groups are monophyletic (i.e., sections Andiphilum (Schott) Croat, Calomystrium (Schott) Engl., Dactylophyllium (Schott) Engl., Leptanthurium (Schott) Engl., Polyphyllium Engl., Tetraspermium (Schott) Engl., and the newly recognized section Multinervia (Croat) Carlsen & Croat, previously a series within section Pachyneurium (Schott) Engl.). All other sections are either not monophyletic or their monophyly could not be accurately tested. A complete revision of the sectional classification of Anthurium will require a more comprehensive taxon sampling and a better supported molecular phylogeny.

This paper presents an exhaustive review of the current knowledge on pollination of Araceae genera with bisexual flowers. All available studies on floral morphology, flowering sequence, floral scent, floral thermogenesis, floral visitors, and pollinators were carefully examined, with emphasis on the species-rich genera Anthurium Schott, Monstera Adans., and Spathiphyllum Schott. Genera with bisexual flowers are among the early-diverging lineages in Araceae, but present adaptations in their floral ecology to a great variety of pollination vectors, such as bees, beetles, flies, and, unusually, wind. These clades have developed highly derived pollination systems, involving the use of floral scent as a reward. We conclude that floral scent chemistry plays a key role in the pollination biology of the plants and that, in some genera, reproductive isolation through variation in the emitted floral volatile compounds may have been the decisive factor in the speciation processes of sympatric species.

This paper is the first in an expected series of publications treating the Araceae of the Lita–San Lorenzo Region of northwestern Ecuador. An introduction to the physical and ecological characteristics of the area is given, and Anthurium Schott sect. Polyneurium Engl. is redefined and typified. Thirty-four species in section Polyneurium are fully described of which 13 are new species of Anthurium: A. bruxellense Croat, A. chuchubiense Croat, A. cornejoi Croat, A. decursivum Croat, A. hannoniae Croat, A. impolitoellipticum Croat, A. kinsingeriae Croat, A. longeinternodum Croat, A. mansellii Croat, A. pandurilaminum Croat, A. pseudotalamancae Croat, A. triangulohastatum Croat, and A. waramirezii Croat. In addition, six seemingly new but (sometimes) sterile species for the region are fully described but not formally named.