Page:VCH Northamptonshire 1.djvu/116

A HISTORY OF NORTHAMPTONSHIRE several that are elsewhere rare or sparingly produced may be found here in great profusion ; among these may be mentioned Tortula pusilla, T. lamellata, T. rigida, T. ambigua, T. aloides, the rare Ceratodon conicus, which occurs frequently and fruits freely on our mud-capped walls, with Tortula intermedia, Pottia intermedia and P. lanceolata, Barbula revoluta, Orthotrichum anomalum var. saxatile, etc. In the calcareous bogs Hypnum commutatum grows in great profusion and variety, while H. falcatum^ H. stellatum, Philonotis calcarea are other characteristic forms. A certain number of our mosses must be considered as the lingering remains of a time when a great part of the county was woodland or open waste land, with a richer moss-flora, much more akin than the present one to the moss vegetation of the hilly and sub-montane districts of Britain. Thus we find a few scattered plants, notably in Badby Wood and Harleston Firs, of such species as Leucobryum glaucum, Plagiothecium undulatum, P. Borrerianum, Ditrichum homomallum, Dicranum majus, Hylo- comium loreum, Sphagnum subsecundum, Eurhynchium myosuroides, Tetraphis pellucida, Bartramia pomiformis and a few others. Most of these occur in a single station only, and are with little doubt doomed to extinction at some not far distant period. A few notes may be added on some species that present features of special interest. Among these is Bryum roseum, one of the most hand- some of our mosses, which produces a rosette of large, deep green leaves at the top of the stem, sometimes measuring as much as an inch across. This, though a local plant and usually not found in any great abundance, occurs in profusion in some parts of Badby Wood, where it may be found in great beauty during the winter months, keeping its -freshness and verdure unimpaired beneath a mantle of brown and withered oak leaves. The very beautiful Schistostega osmundacea is found in one or two of our sandstone quarries, where it lines the walls of fox earths and other crevices with its luminous patches, lighting up the cavity with a lovely golden green refulgence. This was at one time supposed to be a kind of phosphorescent glow, whence the plant acquired the name of the 'luminous moss,' but it is now known to be due to the highly refractive structure of the protonemal threads, and in absolute darkness its beauty disappears. A remarkable form of a somewhat common moss, Porotrichum (better known as Thamnium) alopecurum, occurs in the old disused limestone quarries at Weldon. 'On a recent visit, in the spring of 1898, the bottoms of some low depressions under trees were carpeted with globular masses, which were found to consist of living " balls " of this moss, entirely detached from the soil and without rootlets, and from two to four or five inches in diameter. The interior of the " balls " consisted of the rigid, wiry stems proper to the species, which had branched pro- fusely in all directions, and so produced this peculiar form. The branches were extremely dense and numerous, many hundreds of secondary stems going to make up a single tuft or " ball," and entirely hiding the central stem or stems. From this, as well as from the size of the tufts, 82