Some paleobotanical problematica

Problematica encountered by paleobotanists include objects of two kinds: those clearly belonging to the plant kingdom but temporarily unclassifiable, and those whose identity is more doubtful, often raising questions as to whether or not they are of plant, animal, inorganic, or even artificial origin. Two such specimens, one from Eocene and the other from Miocene strata, are discussed here in the hope of receiving helpful suggestions toward their identification. Another, the supposed Eocene cactus, Eopuntia douglassi Chaney, from the Green River formation, is here considered to be misidentified for the tuberous rootstock of a sedge, Cyperus filiferus(Cookerell) Brown, n. comb.