The Natural History of <i>Equisetum</i> in Costa Rica

Abstract

Observations on the biology of the four horsetails found in Costa Rica are presented. The small Equisetum bogotense ranges from Costa Rica south to Argentina; it is widespread in altitudes between 1000 and 2900 m and shows many similarities with E. arvense ef the North, except for seasonality, to which the local environment is not conducive. Two giant horsetails, E. giganteum and E. myriochaetum, occur in this country. in restricted localities; between 550 and 1400 m only one population of the latter was located, but several sites were recorded for E. Xschaffneri, considered to be all hybrid between the two species.