Thursday, 14 March 2019

Mostly mosses

Yesterday Chris and I pushed the boat out and went to the little café behind Woodford Halse library. We parked the car at the rear where high winds had brought down dozens of cones from a nearby Norway Spruce tree.

The cones of Norway spruce are distinctive and very attractive.
Woodford Halse, 13 March. 2019
I glanced up at the tree and in so doing noticed that a low roof at the edge of the car park was bearing some lovely mosses. For many years now I have been interested in mosses without getting down to a serious study, but these were species characteristic of the habitat and easily recognised. The Ostrich Moss, Grimmia pulvinata, forms slightly furry cushions, and in fact pulvinate means cushion-shaped. It tends to bury its capsules among the leaves like ostrich heads.

Grimmia pulvinata, often referred to as the Ostrich Moss.
Woodford Halse, 13 March, 2019

It is very common on wall-tops and also between paving slabs if traffic is not too heavy.

Equally abundant, and occupying the same habitat is Tortula muralis, the Wall Screw-moss. It common name reflects the way in which its leaves twist up when dry. Our word tortuous comes from the same root. (Not having studied Latin at school I like to chase up the derivation of certain words.)

Tortula muralis is arguably the commonest of wall-top mosses.
Woodford Halse, 13 March, 2019
In very similar habitats is Common Pottia, Tortula truncata. It was once known as Pottia truncata but despite being transferred to a different genus the common name has stuck. This species is frequent on clay soil, sometimes occupying sunken hoof prints.

Tortula truncata forms particularly green cushions.
Woodford Halse, 13 March, 201

These three mosses are also common in flower pots and so the gardener soon becomes familiar with them. They are able to endure extreme drought conditions on sunny wall tops and will bounce back quickly after rain. During a rain storm they will absorb water like a sponge, helping them through to the next shower. They often contain an interesting range of mini-beasts including springtails and, if you are lucky, a few of this planet's most extraordinary creatures, tardigrades. So odd are these creatures that some have speculated that they arrived on earth via a meteorite or something similar. But I mustn't get started on that topic!

Ah, if only there were a few more hours in each day. 

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