Encalypta streptocarpa Hedw., with Gemmae

Abstract

In October, I927, while on a motor trip from Wells, in Somersetshire, to the coast of the Bristol Channel, I stopped for lunch on the Mendip Hills. On a limestone wall-top by the side of the moorland road, I gathered a small quantity of what I took to be Encalypta streptocarpa; not being an authority, I decided to take it home and examine it with the microscope. On examining the specimen at home I found the following points, and decided later they were worth reporting: Save for the fact that the moss was rather browner than usual, it appeared normal in habit; the leaves were not deformed in any way; there were no fruits. With the hand-lens, conspicuous brown bunches of gemmae were visible arising from the axils of the leaves, more especially of those near the apex of the stems. Microscopic examination.-On detaching some leaves from as close to the stem as possible it was found that there arose from the stem long bunches of slender brown processes that later on spread out rather like a graden besom (i. e. a brush made of heather or hazel twigs). They were very friable. During the first or proximal half of their length there was little branching, and, what branches there were, were fastigiate. About half way up, branching became frequent and crowded, and the resulting processes became more curled and twisted. These terminal branches often bore or were terminated by clavate expansions. In many cases these spherical or polygonal masses were seen lying loose among broken branches. The long stalks (proximal half of the processes) were pale brown and translucent; cell-divisions were few and far between, and were usually placed very obliquely to the long axis. Farther up, the celldivisions became more obvious, transverse in direction and closer together till the cells became quadrate-cylindrical in shape. In some of the branches the cells were not quadrate, but more funnelor wineglass-shaped, the distal end bulging round the proximal end of the next cell. Branches appeared to originate as lateral buds from cells, which thus became shaped like a blunt V. Save for the extreme growing apex of the branches, which were pale green, the whole of the rest of the branches were dark brown.