Cryptochlorophyllous Spores in Ferns: Nongreen Spores that Contain Chlorophyll

Abstract

In terms of color, fern spores have traditionally been classified as either green or nongreen. This study reports a new kind of spore, here termed “cryptochlorophyllous.” Such spores contain chlorophyll but do not appear green when examined with either the naked eye or a light microscope. Epifluorescence microscopy was used to detect chlorophyll in cryptochlorophyllous spores. To test one aspect of the reliability of this method, we examined whether chlorophyll degradation over time would give false negative results. We found that in two species with green spores (Osmundastrum cinnamomeum and Terpsichore asplenifolia), fluorescence weakened with but could still be detected in specimens that were 110 yr old. We surveyed the spores of species in three fern genera under white light and with epifluorescence microscopy. Under white light, green spores were seen in 10 (26%) of 39 species of Elaphoglossum, two (17%) of 12 species of Lomariopsis, and seven (25%) of 28 species of Pleopeltis. When spores from the s...