Figure 1 from: Harris AJ, Chen Y, Olsen RT, Lutz S, Wen J (2017) On merging Acer sections Rubra and Hyptiocarpa: Molecular and morphological evidence. PhytoKeys 86: 9-42. https://doi.org/10.3897/phytokeys.86.13532

Figure 1 - Typical specimens of Acer sects. Rubra and Hyptiocarpa, especially exhibiting leaf macromorphology. A A. rubrum B A. pycnanthum C A. saccharinum D A. laurinum. Specimens deposited at US national herbarium, and accession information visible in images. Detailed specimen records are available via the US online catalog (http://collections.nmnh.si.edu/search/botany/).