An Extraordinary Rosette and Resurrection New Spikemoss, Selaginella iridescens (Selaginellaceae) from Hainan Island, China

Selaginella iridescens (Selaginellaceae), a new species of spikemoss from Hainan Island, China, is described based on morphological and molecular evidence. The new species morphologically resembles S. pseudotamariscina from Vietnam which was recently recognized and segregated from S. tamariscina and S. pulvinata. Some characters of S. iridescens, including the iridescent leaves and long arista (0.35–1.20 mm long), the widely membranaceous margin of axillary leaves (ca. 2/3), dorsal leaves sulcate extending to the top, and slender main stem, dorsoventrally prostrate, distinguish it from S. pseudotamariscina. Phylogenetic results based on rbcL of 28 Selaginella species indicate that S. iridescens is sister to S. pseudotamariscina, and distant from the S. tamariscina-S.pulvinata clade. The ancestral character reconstruction result reveals that the rosette is apomorphic and has evolved independently at least six times in Selaginella.

Molecular Phylogeny, Character Evolution, and Biogeography of Hydrangea Section Cornidia, Hydrangeaceae

Background:Hydrangea section Cornidia consists of 26 currently accepted species and a yet undefined number of new species and erroneously synonymized taxa. This clade consists of (sub)tropical lianas occurring from northern Mexico to southern Chile and Argentina, and one species from Southeast Asia. Currently, no molecular phylogenetic hypothesis is available that includes more than a few species of this section. Hence, a resolved and well-sampled molecular phylogenetic hypothesis may help to enforce taxonomic decisions. In this study, we present a phylogenetic framework based on sequences from two low copy nuclear genes from a comprehensive taxon sampling of H. section Cornidia and a selection of outgroups. Our phylogenetic reconstructions prove the non-monophyly of the traditionally recognized subsections Monosegia and Polysegia and their corresponding series, Speciosae and Aphananthae, and Synstyleae and Chorystyleae, respectively. Three morphologically defined species were recovered with high support as monophyletic, namely, Hydrangea panamensis, Hydrangea serratifolia, and Hydrangea tarapotensis. However, statistical support for some shallow nodes did not allow to refute, with high support, the monophyly of several of the herein recognized species for which more than one individual could be analyzed. Based on the obtained phylogenetic framework, we reconstructed the evolution of selected reproductive characters. Hydrangea section Cornidia is the only genus section for which dioecism has been extensively documented. Our character reconstruction of sexual dimorphism shows that dioecism is the ancestral state in this section and that this was reversed to monoecy in Hydrangea seemannii and Hydrangea integrifolia. Character reconstruction for the enlarged marginal flowers recovered their presence as the ancestral character state in H. section Cornidia, although at least three internal lineages independently lost them; thus, losses were reconstructed to be more likely than gain. With respect to the flower color, more species exhibit white than red flowers, and white is reconstructed as the ancestral state. Cornidia also shows an unusual disjunct geographic distribution between Asia and Central Mesoamerica—South America, as it is not present in the USA and Canada. The origin of Cornidia is reconstructed to be the New World with higher probability, and the presence of one species in Asia is likely due to long-distance dispersal.

An updated generic circumscription for Cryptangieae (Cyperaceae, Poales) based on a molecular phylogeny and a morphological character reconstruction

Cryptangieae is a monophyletic tribe, as asserted in a recent molecular hypothesis, but there are questions about the circumscription and relationships of its genera. We enlarged the sampling of the tribe diversity, including about 80% of known species, and provide new analyses using single and combined matrices from two chloroplast (rbcL and trnL-F) and three nuclear ribosomal (ITS, ETS and 5S-NTS) regions with Bayesian Inference to clarify these questions. We also performed character reconstruction analyses with diagnostic morphological characters, including some traditionally applied in Cryptangieae taxonomy, using parsimony methods. The molecular analyses show Lagenocarpus in the current circumscription as polyphyletic, and the need to merge Cephalocarpus and Everardia to avoid paraphyletic genera. We propose an updated circumscription following the phylogeny, including a new name to a group at generic level (Krenakia); and discuss the phylogenetic significance of the morphological characters in Cryptangieae taxonomy. Though the relationship among some genera still needs more research, the genera we propose are strongly supported clades with clear morphological synapomorphies. Additionally, we provide an identification key, a brief description of genera and a list of accepted species including the required new combinations.

Molecular phylogeny and biogeography of Pabstiella (Pleurothallidinae: Orchidaceae) highlight the importance of the Atlantic Rainforest for speciation in the genus

Pabstiella consists of c. 130 epiphytic species in the Neotropics. We present a phylogenetic analysis based on nrITS, matK and trnH-psbA sequences from 59 species of the genus and 40 Pleurothallidinae and two Laeliinae and one Bletiinae as an outgroup, using maximum likelihood, Bayesian inference and maximum parsimony. We also performed molecular dating, biogeographical analyses and ancestral morphological character reconstruction. Our results confirm the monophyly of Pabstiella with strong support. Ten clades are inferred and are herein proposed as sections. Pabstiella originated in the Andes and the Atlantic Rainforest in the Late Miocene (c. 7.93 Mya) in an epoch when these biomes were probably connected. A main vicariance event divided an early-diverging lineage that inhabited the Andes from an Atlantic Rainforest lineage that diversified in this region during the Pliocene and Pleistocene, mainly in the Serra do Mar in south-eastern Brazil. Our findings also suggest that the Atlantic Rainforest may have played an important role in the origin of subtribe Pleurothallidinae. The morphological character reconstruction showed high levels of homoplasy, with few recognized synapomorphies associated with stems and petals. Other characters related to the habit and stems were identified as important in the evolutionary history of the genus.

Coping with the extremes: comparative osteology of the tepui-associated toad Oreophrynella and its bearing on the evolution of osteological novelties in the genus

The only study of the osteology of the toad genus Oreophrynella dates back to 1971 and was based on a single species. Here, we use high-resolution X-ray microcomputed tomography to analyse the osteology of all nine described Oreophrynella species, which are compared with representatives of other bufonid lineages. Oreophrynella is unique among bufonids in having opposable digits. Osteological synapomorphies confirmed for the genus are as follows: presence of parietal fontanelles and exposed frontoparietal fontanelle, absence of quadratojugal, five presacral vertebrae, distally enlarged terminal phalanges and urostyle greatly expanded into flanges. Ancestral character reconstruction indicates that arboreal habits in some Oreophrynella species are likely to have evolved after the evolution of opposable digits. Opposable digits, in combination with an extension of the interdigital integument and the relative length/orientation of the digits, are likely to be adaptations to facilitate life on rocky tepui summits and an exaptation to arboreality. Cranial simplification in Oreophrynella, in the form of cranial fontanelles and absence of the quadratojugal, is possibly driven by a reduction of developmental costs, increase in flexibility and reduction of body weight. Cranial simplification combined with the shortening of the vertebral column and the shift towards a partly firmisternal girdle might be adaptations to the peculiar tumbling behaviour displayed by Oreophrynella.

The role of floral oils in the evolution of apid bees (Hymenoptera: Apidae)

Most bees collect pollen and nectar for their larvae, while some also collect other resources. We investigated the evolution of floral oil-collecting behaviour in the Apidae and the evolutionary effects of floral oils on host brood cells for cuckoo bees. Focusing on apid bee phylogeny, we reconstructed the evolution of floral oil collection by females, use of floral oils in cell construction and the inclusion of oils in provisioning immatures. Ancestral character reconstruction demonstrates that floral oil-collecting behaviour arose four times independently. We also found that in cuckoo bees, parasitization of oil-collecting bees arose three times (including one secondary return) in Apidae. Except for Ctenoplectrina, oil cuckoo bees are all closely related to each other, forming an independent clade within the Nomadinae. Analysis of evolutionary transition rates indicates that there is a greater tendency for switching from an oil-collecting host to a non-oil-collecting host than the reverse. In apid bees, evolutionary transition rates are higher for switching to cuckoo behaviour from an ancestral lineage in which females collect floral oils than from other pollen-collecting lineages. We conclude that adaptation to oil collection is advantageous for pollen-collecting bees, and that the origin of oil cuckoo bees from non-oil cuckoo bees is constrained.