Much of the golden moss mortared to old walls and gathered round the feet of park trees turns out to be a single species, and a distinctive one once you have its measure. Silky wall feather-moss (Homalothecium sericeum) mats itself flat over stone and bark in a glossy yellow-green weft, then, as it dries, lifts and twists its branch tips into small hooks so the whole patch turns wiry and faintly ruffled. That drying habit, more than size or colour, is what puts a name to it.
Free PDF
Get the free Moss Care Cheat Sheet
One printable page on light, water and patience for terrariums, walls and gardens. Leave your email and pick it up, plus occasional unhurried notes on growing moss.
Free, one click to unsubscribe. The download starts as soon as you have signed up.
A golden weft that curls as it dries
Wet, the moss lies close and smooth against its surface, with a silky sheen that the Latin name records (sericeum means silky), the colour somewhere between fresh yellow-green and old gold. The shoots branch irregularly and weave into a dense mat, each leaf folded lengthways into fine pleats and drawn out to a slender point, pressed tight along the stem. Let it dry, though, and the character changes entirely: the branch ends curl and turn away from the stone, hooking outward, and a patch that looked neat an hour ago now reads shaggy and combed-back. Draw a dry thumb across the moss on any old churchyard wall and those curled golden tips are far more often this than anything else.
Lime, old stone and weathered bark
This is a lime-lover through and through. It takes to mortared brick and stone walls, limestone outcrops, concrete, gravestones and the base-rich bark of older wayside trees such as ash, elm and sycamore, favouring the drier, harder surfaces that many mosses cannot hold. Sun and drought scarcely trouble it. On a south-facing wall in my own garden it bakes to a hard grey crust through July, looking for all the world like something dead, and greens again within the hour once rain reaches it. If you are working out the mosses on your brickwork or your trees, it sits among the regulars covered in moss on walls and moss on trees, and it is one of the first colonists to expect on new concrete once it has weathered.
Sorting it from its neighbours
The moss most often confused with it is rough-stalked feather-moss, and colour usually settles the pair: that species runs a plain glossy green, sprawls more loosely, keeps to damper and richer ground, and never curls its tips into the same tight hooks. On chalk turf and dune you may meet a closer relative, yellow feather-moss (Homalothecium lutescens), which shares the curling habit but grows more on the ground, looks duller and more matt, and tapers its leaves more gradually. Sharing the very same wall, quite often, is wall screw-moss, though there is little real risk of muddling them once you notice it grows in low grey cushions tipped with white hairs rather than in a creeping weft; the two belong to opposite camps, a distinction worth understanding through acrocarpous and pleurocarpous growth and illustrated further in wall screw-moss.
The rough red seta
Fruit comes fairly freely from late winter into spring, and it carries a useful clue. The capsule stands erect and narrowly cylindrical, barely curved, on a reddish stalk that feels rough to a hand lens, minutely bristled all over with tiny papillae. Run a lens down that stalk and the roughness is unmistakable; it separates Homalothecium at a stroke from the smooth-stalked feather-mosses it grows beside, whose capsules also tend to hang over on a curved neck rather than sitting upright. A capsule is not needed to name this moss, given how boldly it curls, but the rough seta is a satisfying confirmation when one is to hand.
A moss to admire in place
I would not try to grow it. It belongs to hard, dry, limy surfaces and sulks the moment you shift it to soft ground or the damp of a jar, so it repays admiration far better than cultivation. Where you want stone or rendered block to green over, it tends to arrive of its own accord provided the surface is limy enough, and the patience that asks for is much the same as in growing moss on concrete. Its real gift is as a reliable name to hand out on any town or churchyard walk, a common moss most people pass without a glance, and good practice for the eye when you are learning to tell mosses apart.