2016-2020

• Phenology is a key aspect of plant success. Recent research has demonstrated that herbarium specimens can provide important information on plant phenology. Massive digitization efforts have the potential to greatly expand herbarium-based phenological research, but also pose a serious challenge regarding efficient data collection.
• Here, we introduce CrowdCurio, a crowdsourcing tool for the collection of phenological data from herbarium specimens. We test its utility by having workers collect phenological data (number of flower buds, open flowers and fruits) from specimens of two common New England (USA) species: Chelidonium majus and Vaccinium angustifolium. We assess the reliability of using nonexpert workers (i.e. Amazon Mechanical Turk) against expert workers. We also use these data to estimate the phenological sensitivity to temperature for both species across multiple phenophases.
• We found no difference in the data quality of nonexperts and experts. Nonexperts, however, were a more efficient way of collecting more data at lower cost. We also found that phenological sensitivity varied across both species and phenophases.
• Our study demonstrates the utility of CrowdCurio as a crowdsourcing tool for the collection of phenological data from herbarium specimens. Furthermore, our results highlight the insight gained from collecting large amounts of phenological data to estimate multiple phenophases.

Aim When precise coordinate data for training species distribution models (SDMs) are lacking, climatic variables are often assigned to centroids of geopolitically defined regions, frequently counties. This is problematic because approximations using centroids may not be representative of the regional climate or the locality from where species actually occur, thus leading to spurious conclusions. We evaluated county centroid climate versus simple alternatives for assigning climate to species observations in the absence of precise occurrence data.

Location United States of America.

Methods We assessed the disparity between the actual climate of all points within a county and metrics estimating county climate using the climate of geographical centroid, mean county climate and median county climate. To further evaluate the performance of these metrics, we generated SDMs of four common species using these estimates and compared the results with observed

species distributions (red trillium, Pacific trillium, tall thistle and annual fleabane). Finally, we projected future ranges for annual fleabane to examine the difference in predicted range change between models.

Results Mean and median climate metrics were significantly better fits for approximating the climate of specimen records than climate of the geographical centroid. Moreover, county mean climate SDMs were the most similar to SDMs using actual coordinate data. In contrast, models applying climate to county centroid significantly overpredicted species range. This had implications for future projections of annual fleabane SDMs: the county centroid model predicted a decrease in suitable habitats for this species while other models predicted an increase.

Main conclusions County centroid climate, although commonly applied, is not suitable for SDMs as a means to approximate species climate when locality data are less precise. When only county level data are available, and more computationally intensive methods of accounting for spatial uncertainty cannot be readily implemented, we suggest considering mean county climate as an alternative.

Premise of research. The primarily Neotropical Malpighiaceae exhibit an elegant suite of floral morphological characteristics associated with a specialized mutualism with oil bee pollinators, including bilaterally symmetrical flowers and paired oil glands on the calyx. One clade within the family, Hiptage Gaertn., has migrated to the paleotropics and lost its association with oil bees. Corresponding to this transition, some members of Hiptage have evolved a highly elaborate zygomorphic corolla with strongly reflexed petals and striking dorsoventral heteranthery. Previously, we demonstrated that expression of CYCLOIDEA2-like (CYC2-like) genes is correlated with the evolution of floral symmetry in Malpighiaceae. Here, we examine CYC2expression in relation to the evolution of elaborate floral zygomorphy in Hiptage benghalensis.

Methodology. CYC2-like genes were cloned from H. benghalensis. The spatial pattern of CYC2 expression was examined with quantitative reverse-transcription PCR on the dissected floral organs.

Pivotal results. While most Neotropical Malpighiaceae express two CYC2-like genes, CYC2A and CYC2B, we demonstrate that H. benghalensis has experienced further duplications yielding four copies, which are expressed in all four whorls of the flower. As in Neotropical Malpighiaceae, CYC2A homologs HbCYC2A-1 and HbCYC2A-2 are expressed broadly in the dorsal region of the flower, but unlike that in other Neotropical species, expression also extends to the dorsal stamens. The CYC2B copies HbCYC2B-1 and HbCYC2B-2 are intensely expressed in the single dorsal petal (as in Neotropical Malpighiaceae), but their expression is further detected in the other floral whorls, especially in the stamens of the dorsal region.

Conclusions. The relaxation of the conserved expression of CYC2-like genes in Neotropical Malpighiaceae and the expansion to broader floral regions, including the dorsal androecium, correlate with the development of dorsoventral heteranthery in H. benghalensis. We propose that changes in the pattern of CYC2 expression may have contributed to the elaborated androecium of H. benghalensis, which was crucial for its adaptation to a novel pollination strategy.

The tropical Andes of South America, the world's richest biodiversity hotspot, are home to many rapid radiations. While geological, climatic, and ecological processes collectively explain such radiations, their relative contributions are seldom examined within a single clade. We explore the contribution of these factors by applying a series of diversification models that incorporate mountain building, climate change, and trait evolution to the first dated phylogeny of Andean bellflowers (Campanulaceae: Lobelioideae). Our framework is novel for its direct incorporation of geological data on Andean uplift into a macroevolutionary model. We show that speciation and extinction are differentially influenced by abiotic factors: speciation rates rose concurrently with Andean elevation, while extinction rates decreased during global cooling. Pollination syndrome and fruit type, both biotic traits known to facilitate mutualisms, played an additional role in driving diversification. These abiotic and biotic factors resulted in one of the fastest radiations reported to date: the centropogonids, whose 550 species arose in the last 5 million yr. Our study represents a significant advance in our understanding of plant evolution in Andean cloud forests. It further highlights the power of combining phylogenetic and Earth science models to explore the interplay of geology, climate, and ecology in generating the world's biodiversity.