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Premise of research. Fossils of asymmetrically winged samaras, informally referred to as Acer negundoides MacGinitie (Sapindaceae), from the late Eocene–early Oligocene Badger’s Nose flora (∼34 Ma) of northern California, are described as Deviacer pidemarmanii Myers and Erwin sp. nov. The genus Deviacer Manchester is emended and attributed to the family Polygalaceae.Methodology. The morphological features of more than 40 samaras exquisitely preserved as compressions in lacustrine siltstone of the Badger’s Nose member of the Steamboat Formation were compared to similar extant and fossil-winged fruits.Pivotal results. Deviacer includes compressions of nonschizocarpic asymmetrical samaras with a small dorsal projection. Similar projections characterize the fruits of extant Securidaca (Polygalaceae) and the extinct genus Paleosecuridaca Pigg, Devore, and Wojciechowski, but Acer L. (Sapindaceae) fruits lack these structures. Morphologically, Deviacer is indistinguishable from the anatomically preserved fruits ...

High diversity and endemism in the California Floristic Province (CFP) are an alleged response to the late Cenozoic advent of Mediterranean-type climate in this region. Ceanothus comprises two divergent subgenera with centers of diversity in the CFP. We reconstruct the evolution of Ceanothus by using DNA sequence data from the nuclear gene nitrate reductase. We find that the timing of diversification events is related to geological and climatic history. In both subgenera, diversification is characterized by recent divergence of extant taxa and geographically structured phylogenetic relationships. A strong north-south divergence of subgenus Cerastes across the Transverse Ranges indicates that phylogenetic relationships may be structured by climatically divergent regions of the CFP. Divergence-time estimation suggests that the age of extant diversification in both subgenera is ∼6 Ma. This agrees with the fossil record but predates the hypothesized Quaternary (2-Ma) origin of Mediterranean-type climate in th...

Lyonothamnus Gray is a monotypic genus of evergreen trees endemic to California's Channel Islands. There is one species, L. floribundus, with two subspecies, ssp. floribundus and ssp. asplenifolius. Subspecies floribundus has simple and entire-margined leaves, while leaves of ssp. asplenifolius are pinnate and composed of three to seven primary segments. Despite its restricted modern occurrence, three fossil species have been described from Neogene paleofloras in the far western United States. Lyonothamnus mohavensis Axelrod is known from California; L. parvifolius (Axelrod) Wolfe and L. cedrusensis Axelrod, from Nevada. However, the size ranges used to segregate these species were all found to fall within the range of L. parvifolius from Stewart Valley, Nevada. Study of intact leaves reveals that the combination of (1) number of primary segments, (2) length of primary segments, (3) number of medial secondary segments per primary segment, and (4) lengths and widths of medial secondary segments is important in segregating species. Using these characters, L. parvifolius and L. wolfei Erwin et Schorn sp. nov. are recognized from Nevada and Oregon, and two species, L. mohavensis and L. axelrodii Erwin et Schorn sp. nov., from California. This renewed taxonomy within an updated temporal framework provides an important first step toward understanding the evolution, diversity, paleoecology, and paleobiogeographic history of this unusual member of the Rosaceae.