The family Orchidaceae exhibits some of the most diverse and intricate modes of animal pollination across angiosperms. Highly specialized pollination by male euglossine bees (Apidae, Euglossini) occurs in more than 600 species of Neotropical orchids. Male euglossine bees acquire volatile compounds from both floral and nonfloral sources, which they store in their specialized hind tibiae and later expose during courtship display. Euglossine-pollinated Orchidaceae produce large quantities of floral scent, which serves as both the attractant and reward for male euglossine bees. Upon collecting floral volatiles and aided by the intricate orchid floral morphology, male bees remove and subsequently deposit orchid pollinaria, resulting in pollination. Among euglossine-pollinated Orchidaceae is the species-rich genus Gongora Ruiz & Pav., which provides exceptional opportunities to investigate the evolution of scent-mediated pollinator specialization. Here we review the taxonomy, systematics, and pollination biology of Gongora. We also describe a new physical mechanism of pollination observed for Gongora and discuss the significance of different modes of pollinaria attachment in an evolutionary framework. This work provides the foundation for future research on the evolution of specialized plant–pollinator mutualisms, including elucidating the evolutionary relationships of cryptic species, understanding the evolution of floral adaptations, and investigating the mechanisms of speciation.

Birds represent the most diverse extant tetrapod clade, with ca. 10,000 extant species, and the timing of the crown avian radiation remains hotly debated. The fossil record supports a primarily Cenozoic radiation of crown birds, whereas molecular divergence dating analyses generally imply that this radiation was well underway during the Cretaceous. Furthermore, substantial differences have been noted between published divergence estimates. These have been variously attributed to clock model, calibration regime, and gene type. One underappreciated phenomenon is that disparity between fossil ages and molecular dates tends to be proportionally greater for shallower nodes in the avian Tree of Life. Here, we explore potential drivers of disparity in avian divergence dates through a set of analyses applying various calibration strategies and coding methods to a mitochondrial genome dataset and an 18-gene nuclear dataset, both sampled across 72 taxa. Our analyses support the occurrence of two deep divergences (i.e., the Palaeognathae/Neognathae split and the Galloanserae/Neoaves split) well within the Cretaceous, followed by a rapid radiation of Neoaves near the K-Pg boundary. However, 95% highest posterior density intervals for most basal divergences in Neoaves cross the boundary, and we emphasize that, barring unreasonably strict prior distributions, distinguishing between a rapid Early Paleocene radiation and a Late Cretaceous radiation may be beyond the resolving power of currently favored divergence dating methods. In contrast to recent observations for placental mammals, constraining all divergences within Neoaves to occur in the Cenozoic does not result in unreasonably high inferred substitution rates. Comparisons of nuclear DNA (nDNA) versus mitochondrial DNA (mtDNA) datasets and NT- versus RY-coded mitochondrial data reveal patterns of disparity that are consistent with substitution model misspecifications that result in tree compression/tree extension artifacts, which may explain some discordance between previous divergence estimates based on different sequence types. Comparisons of fully calibrated and nominally calibrated trees support a correlation between body mass and apparent dating error. Overall, our results are consistent with (but do not require) a Paleogene radiation for most major clades of crown birds.

The fossil record provides good evidence for the minimum ages of important events in the diversification and geographic spread of Asteridae, with earliest examples extending back to the Turonian stage of the Late Cretaceous (~89 million years ago [Ma]). Some of the fossil identifications accepted in previous considerations of asterid phylogeny do not stand up to careful scrutiny. Nevertheless, among major clades of asterids, there is good evidence for a range of useful anchor points. Here, we provide a synopsis of fossil occurrences that we consider reliable representatives of modern asterid families and genera. In addition, we provide new examples documented by fossil-dispersed pollen investigated by both LM and SEM studies including representatives of Loranthaceae, Amaranthaceae, Cornaceae (including Nyssa L., Mastixia Blume, Diplopanax Hand.-Mazz.), Sapotaceae, Ebenaceae, Ericaceae, Icacinaceae, Oleaceae, Asteraceae, Araliaceae, Adoxaceae, and Caprifoliaceae from Paleogene sites in Greenland, western North America, and central Europe, and of Lamiaceae and Asteraceae from the Middle to Late Miocene in northeastern China. We emphasize that dispersed pollen, taken along with megafossil and mesofossil data, continue to fill gaps in our knowledge of the paleobotanical record.

Lepidopilidium (Müll. Hal.) Broth. (Pilotrichaceae) consists of mainly epiphytic and epiphyllous, pleurocarpous mosses distributed in the tropical, subtropical, and south temperate regions of Central America, South America, Africa, southern India, and Sri Lanka. The genus is characterized by a moderately to strongly complanate habit; the presence of a moderately to well-developed stem hyalodermis; dimorphic dorsal, ventral, and lateral leaves; prominent double costae; smooth, hexagonal, rhomboidal, or fusiform leaf cells; smooth or papillose setae; collenchymatous exothecial cells; 2-celled stomata; massive annuli; a hookeriaceous-type peristome; and sparsely pilose or glabrous mitrate calyptrae. Six species are taxonomically accepted: L. brevisetum (Hampe) Broth., L. devexum (Mitt.) Broth., L. divaricatum (Dozy & Molk.) Broth., L. furcatum (Thwaites & Mitt.) Broth., L. isleanum (Besch.) Broth., and L. nitens (Hornsch.) Broth., with 19 names newly synonymized. Lepidopilum chenagonii Renauld & Cardot is transferred to Thamniopsis (Mitt.) M. Fleisch., as T. chenagonii (Renauld & Cardot) J. J. Atwood. Lepidopilidium crispifolium W. R. Buck & Wigginton and Hookeria pallidifolia Mitt. are placed in Hookeriopsis (Besch.) A. Jaeger s. str., as H. crispifolia (W. R. Buck & Wigginton) J. J. Atwood and H. pallidifolia (Mitt.) Geh. & Herzog, respectively. Lepidopilum plebejum (Müll. Hal.) Sehnem is treated as a new synonym of Lepidopilum pallidonitens (Müll. Hal.) Paris. Typification is designated for the unranked Lamprophyllum group of Hookeria Sm. by Hookeria nitens Hornsch. [≡ Lepidopilidium nitens] and for Lepidopilum sect. Plagiotheciella Besch. by Lepidopilum isleanum Besch. [≡ Lepidopilidium isleanum]. Typifications are designated for Crossomitrium portoricense Müll. Hal. [≡ Lepidopilidium portoricense (Müll. Hal.) H. A. Crum & Steere; = L. nitens], Hookeria aureopurpurea Geh. & Hampe [≡ Lepidopilidium aureopurpureum (Geh. & Hampe) Broth.; = L. nitens], Hookeria aureopurpurea Müll. Hal. [≡ Lepidopilidium lamprophylloides (Paris) Broth.; = L. brevisetum], Hookeria breviseta Hampe [≡ Lepidopilidium brevisetum], Hookeria divaricata Dozy & Molk. [≡ Lepidopilidium divaricatum], Hookeria entodontella Müll. Hal. ex Broth. [≡ Lepidopilidium entodontella (Müll. Hal. ex Broth.) Broth.; = L. nitens], Hookeria gracilifrons Müll. Hal. [≡ Lepidopilidium gracilifrons (Müll. Hal.) Broth.; = L. nitens], Hookeria longicuspis Müll. Hal. [≡ Lepidopilidium longicuspis (Müll. Hal.) Broth.; = L. nitens], Hookeria nitens Hornsch. [≡ Lepidopilidium nitens], Hookeria subnitens Geh. & Hampe [≡ Lepidopilidium subnitens (Geh. & Hampe) Broth.; = L. nitens], Hookeria subnitens Geh. & Hampe var. latior Geh. & Hampe [= Lepidopilidium nitens], Hookeria tenuiseta Müll. Hal. [≡ Lepidopilidium tenuisetum (Müll. Hal.) Broth.; = L. nitens], Hookeria wainioi Broth. [≡ Lepidopilidium wainioi (Broth.) Broth.; = L. nitens], Lepidopilum corbieri Renauld & Cardot [≡ Lepidopilidium corbieri (Renauld & Cardot) Cardot; = L. divaricatum], Lepidopilum devexum Mitt. [≡ Lepidopilidium devexum], Lepidopilum flexuosum Besch. [≡ Lepidopilidium flexuosum (Besch.) Broth. ex Paris; = L. isleanum], Lepidopilum fruticola Müll. Hal. [≡ Lepidopilidium fruticola (Müll. Hal.) Broth.; = L. brevisetum], Lepidopilum furcatum Thwaites &am

Recent work suggests that Fusispermum Cuatrec. and Rinorea Aubl. form small clades that are sister to the rest of the Violaceae and that the Goupiaceae is sister to the Violaceae. However, little is known about the morphology and anatomy of these phylogenetically critical groups. In this paper I present aspects of the morphology and anatomy of stem, node, leaf, flower, and seed of three species of Fusispermum and seven species of Rinorea, as well as Goupia glabra Aubl. (Goupiaceae), which is the outgroup. Placing this variation in the context of hypothesized phylogenetic relationships, I found Fusispermum to have unique pentalacunar nodes, heterogeneous pith, and elongated seeds, while Goupia Aubl. has a unique 5-carpellate gynoecium with marginal styles and a tegmen with U-shaped thickenings. Furthermore, variation in androecium and nectary links the distinctive androecium so common in the Violaceae with more conventional structures found in other taxa of the parietal placentation group of Malpighiales. Strengthening our basic knowledge of anatomy and morphology in these groups is an essential prerequisite for understanding the evolution and diversification not only of Violaceae but of Malpighiales as a whole.

In June and July 1841, Lt. John Charles Frémont of the United States Army Corps of Topographical Engineers led a survey of the lower Des Moines River in the territory of Iowa and the state of Missouri, accompanied by botanist Karl Andreas Geyer. The resulting publication was the earliest to report on the flora of Iowa in any sort of scientific fashion. Frémont described the major plant communities encountered, in the process mentioning 30 species: 24 trees and shrubs of the forest and six herbs of the prairie. Seven herbaceous species not mentioned in the report are documented by specimens in the herbarium of Missouri Botanical Garden.

A multivariate morphometric study of Solidago L. in South America was undertaken to assess the numbers and ranks of taxa that could be usefully recognized. The results of stepwise discriminant, classificatory, and canonical analyses on a matrix of 50 traits of 160 specimens indicated the distinctiveness of the S. chilensis group of taxa from three morphologically similar North American species of the large Solidago subsect. Triplinerviae (Torr. & A. Gray) G. L. Nesom: S. juliae G. L. Nesom, S. leavenworthii Torr. & A. Gray, and S. tortifolia Elliott. Within the South American complex two species with predominantly allopatric distributions were statistically supported: S. chilensis Meyen and S. microglossa DC. were distinguished a priori on stem hair length. The cytogeography of the two species was investigated and all samples were diploid, 2n = 18; S. chilensis (20 individuals from Argentina and one from Chile) and S. microglossa (six individuals from Argentina). Also, two other species of Solidago in South America that are not members of subsection Triplinerivae were found to have been misidentified as members of the S. chilensis complex; European S. virgaurea L. is a member of Solidago subsect. Solidago and native S. argentinensis Lopez Laphitz & Semple is a member of Solidago subsect. Junceae (Rydb.) G. L. Nesom. The name S. chilensis is neotypified.