apocarpa: The specific name apocarpa means "without fruit," but probably is intended to mean that it
seems to be without fruit. The capsules are inconspicuous,
"immersed" in the leaves until they mature.
hygrometrica, the Cord or Water-measuring Moss, is named for its sensitivity to humidity. When damp, it stands straight with a nodding capsule. Decreasing humidity makes the stalk twist like a cord and the capsule swing in a wide arc, embracing its neighbours in an orgy that leaves them seemingly hopelessly entwined. Return of adequate moisture, even one's breath, quickly restoresthem.