Michael G. Simpson

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Pollen of eight species of Cryptantha was studied using scanning electron microscopy. In addition, transmission electron microscopy was used in Cryptantha intermedia to elucidate the ultrastructural basis for their heterocolpate pollen, in which three " true " colporate apertures alternate with three " pseudoapertures. " Both apertures and pseudoapertures(More)
Pentagramma triangularis (Kaulfuss) Yatskievych, Windham, & E. Wollenweber subsp. rebmanii Winner and M. G. Simpson subsp. nov. is a new subspecies endemic to south-central to southeast San Diego County, California, USA, and inland, northwestern Baja California, Mexico. It is uncommon on seasonally moist, granitic-derived or gabbro-clay substrates,(More)
—Cryptantha (Boraginaceae) is a group of approximately 200 annual and perennial species, representing two-thirds of the diversity within subtribe Cryptanthinae. The genus exhibits an amphitropic distribution, occurring in temperate and desert regions of western North and South America. Fifty samples of 45 species of Cryptantha s. l., exemplars of the(More)
The genus Cryptantha (Boraginaceae) contains 202 species, with 49 species and 56 taxa (including varieties) occurring in Southern California, defined here as including the entire Southwestern California region and Tehachapi Mountain region of the California Floristic province, the entire Desert province, and most of the White and Inyo Mountain subregion of(More)
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Botanical Society of(More)
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Floral anatomy and(More)
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Pollen(More)