Most mosses gather into cushions or creep in flat mats. This one grows like a wood shrunk to the size of your hand. Every shoot rises on a bare stalk that branches only near the top into a rounded spray of foliage, so a colony reads at a glance as a stand of tiny green trees a few centimetres high. Once you have met common tree-moss you will never mistake it, and it is one of very few mosses a beginner can name from right across a meadow.
Recognising it
Climacium dendroides lifts each shoot on a slender, almost leafless stalk that emerges from a stem creeping below the surface, then opens at the crown into a dense head of short, spreading branches. The likeness to a little tree is uncanny, trunk and canopy both, and the name records it plainly: dendroides means tree-like. Shoots stand roughly two to eight centimetres tall, the foliage a fresh yellow-green that ages towards a duller olive. The branch leaves are broad, faintly pleated and blunt-tipped with a minutely toothed edge, so a crown feels a touch stiff and coarse between finger and thumb rather than silky. In dry weather those leaves curl inward and each crown draws up into a small tight fist; a passing shower loosens it again within the hour.
Wet ground, from fen to dune slack
This is a plant of ground that stays wet without tipping over into acid bog. Hunt for it in fens and marshes, in damp unimproved meadows and rushy pasture, along the reedy edges of lakes and slow rivers, and in the moist hollows between coastal dunes that go by the name of dune slacks. It threads up through grass and low sedge rather than knitting a closed carpet, its green trees standing singly or in loose companies among the taller stems. Neutral to gently base-rich conditions are what it asks, so where sphagnum and the sour peat mosses take over, tree-moss quietly bows out. It is widespread through the cooler northern hemisphere yet rarely plentiful, and the draining of wet meadows has thinned it across many lowland districts, so a good stand of it is a small event worth stopping for.
A tree built on a runner
The resemblance to a tree runs deep in one way and misleads in another. Each upright shoot, the part that looks like a sapling, grows from a horizontal stem creeping through the surface litter, which means a whole colony is one connected plant rather than a crowd of separate seedlings, spreading sideways rather as an aspen thicket does from its roots. What it lacks is any trunk that thickens or lasts: the upright is soft tissue that persists a season or two before the runner below renews it. Capsules are produced only now and then and are easily overlooked, upright and cylindrical on reddish stalks, so most colonies get about by creeping growth and by broken fragments far more than by spores. That habit of spreading along a runner is the thing to hold in mind when the time comes to lift a piece.
Growing and showing it off
Among moss gardeners the plant is valued for the very oddity that names it: a ready-made miniature forest that lends a planting real height and structure where cushion and carpet mosses lie flat. It works beautifully in the foreground of a roomy terrarium or a bottle garden, so long as the air stays humid and the base of the colony rests on something that never dries; a pad of wet, low-lime substrate keeps it content, and it sits among the better candidates set out in choosing moss for a terrarium. Out in an open moss garden it wants a dependably damp, part-shaded pocket, much the sort of spot you might hand a patch of sphagnum, disliking both a baking and deep gloom. Since every little tree is joined to its runner, move it as intact sods with the wet base attached; crowns pulled loose from the stem seldom take root again. It is slower and choosier than the vigorous feather mosses, so treat it as a specimen to place with intent rather than a quick way to cover ground.
Finding it, and taking it with care
Because it clings to wet, often protected places, tree-moss deserves particular restraint from anyone tempted to gather it. Many fens and dune slacks are nature reserves or designated sites where lifting any plant at all is forbidden, and even where the law allows it the colonies mend slowly from clumsy digging. Should you take a little from somewhere it grows in real quantity, with the landowner's leave, lift small sods only and keep to the field-craft laid out in collecting moss responsibly. For most of us the better course is to enjoy it on the spot. A company of green trees an inch high, standing out of the wet grass of a summer fen, is among the quietly astonishing sights the moss world can show you, and it loses none of its charm by being left exactly where it stands.