...Police officers stopped their patrol car and watched with suspicion, or with bewilderment—until they caught sight of the T-shirts many of us were wearing which bore slogans such as “American Fern Society” or “Ferns Are Ferntastic.”
We were assembled for a meeting of the American Fern Society, which had joined with the Torrey Botanical Society for a Saturday-morning Fern Foray. These forays, which have been going on for more than a century, are usually in somewhat more bucolic sites, but this time we had no goal beyond the Park Avenue viaduct, which, with its crevices and crumbling mortar, is a perfect place to see chink-finding, xerophytic ferns—ferns that, unlike most, can stand long periods of drying out and come to life again after a good rain.
From "Botanists on Park" by Oliver Sacks in the New Yorker