El género Equisetum L. en el occidente del estado de México, México

Field and laboratory studies of the genus Equisetum indicate that two species (E. myriochaetum and E. hyemale ssp. affine) and two hybrids (E. xferrissii and E. hyermale ssp. affine x myriochaetum) exist in the western part of the state of Mexico.