Krauss's clubmoss
Selaginella kraussiana
Family · Selaginellaceae · Harmless
The bright pale green mat covering the floor of damp valleys in the Azores and Madeira and letting nothing else germinate. It came from Africa as greenhouse ground cover.
Oak woods · Streams and ditches · Walls and rocks · Town and roadside
Also known astrailing spikemoss, African clubmoss
How to tell it
Thin, flattened, creeping stems rooting by white filaments along the way. Minute scale leaves in four rows, two larger spread sideways and two small along the middle. Luminous pale green, almost yellowish, lighter than the native selaginella. It forms continuous dense mats.
What it is confused with
Mediterranean clubmoss
Selaginella denticulata
They are very alike and both look like moss. The native is dark green, grows in small patches on wet stone and does not dominate; Krauss's is pale luminous green and forms continuous mats covering the whole floor. Colour and scale decide.
Open sheet →What it is for
None. It spreads only by fragments, which makes it very hard to remove and very easy to spread: a piece stuck to a boot sole is enough to start a new patch in the next valley. It is one of the practical reasons to clean boots between trails.