Under which conditions do Equisetum spores germinate?

Equisetum spores germinate under conditions of low light intensity and high humidity. Once these conditions are met, the spores develop into small, flattened, green gametophytes.12

Environmental factors, particularly temperature, also influence the development of the resulting gametophytes. For example, research indicates that at higher temperatures, such as 32 °C (about 90 °F), only male gametophytes develop in certain species, whereas at cooler temperatures like 15 °C (59 °F), the population may consist of approximately 50 percent male and 50 percent hermaphroditic gametophytes.2