Identification notes
As experienced bryologists know all too well, identifying common species of Hypnum can be a perilous affair, and many encounters are most safely recorded as ‘Hypnum agg.’.
H. andoi, although currently treated as a full species, was formerly known as Hypnum cupressiforme var. mammillatum, a name which alludes to its distinctive nipple-like capsule lid. Because the shoots of H. andoi can at times resemble those of H. cupressiforme var. cupressiforme and var. resupinatum, the most certain way to separate them is by examination of capsule characters, in the autumn, before the lids fall off. Only H. andoi has the short, nipple-like lid. Like the majority of the common Hypnum species, H. andoi is a calcifuge and so, on living trees, generally prefers hosts with base-poor bark, for example oaks and birches. It also grows on rock, including sarsen stones.
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