Species of the genus Hygrophorus are infrequently encountered in Britain, although twenty species are recorded for the British Isles. They are ecologically distinct from members of the genus Hygrocybe in preferring woodland communities to grassland areas; they are probably mycorrhizal. The anatomy of the fruit-body is also rather different to that found in Hygrocybe; the gill-trama is bilateral as in Leccinum ([p. 27]), Suillus ([p. 28]), Boletus ([p. 31]), Chroogomphus ([p. 36]), Paxillus ([p. 38]) and Amanita ([p. 54]). Members of the genus Hygrocybe have regular to irregular gill-tramas. In fact, although both genera are united into a single family, the Hygrophoraceae is based on one character common to both, i.e. the long basidium; there is every indication that the genus Hygrocybe has greater affinity to Omphalina in the Tricholomataceae ([p. 232]).
Surprisingly enough in North America many of our familiar grassland species including H. pratensis are to be found in deep shaded woodland!
Angular, pink-spored agarics—Rhodophyllaceae
The name of the family refers to the pink gills and it unites all those fungi with a salmon-pinkish buff spore-print and whose spores are angular in all optical sections. There are a few agarics, e.g. Clitopilus prunulus (Fries) Kummer with ridged spores which appear angular in end-on view, but which are ellipsoid in both side and face views and so are considered less related.
The family Rhodophyllaceae by some authorities contains one genus Rhodophyllus, more correctly called Entoloma; in the British Isles five constituent genera are recognised, but they will have to be more critically defined to make a more meaningful classification. At the moment, many of the species are poorly documented and it would appear that anatomical studies will assist in the future in the recognition of species-groups.
If one selects the eight most distinctive shaped spore-types exhibited in members of this family, then when their spores are examined side-on a feature is available for correlation with the traditional field characters, such as cap scaliness and gill-attachment. The most distinctive spore-shape is Type G, found in Nolanea staurospora Bresadola, which is probably the most common and widespread species of the family. It grows in woodlands, grassland and on lawns and will be dealt with later ([p. 122]). The other spore types are illustrated and range from irregularly rhomboid to elongate angular.
The majority of the members of this group grow in grassland, hill-pastures and meadows and distinct communities containing members of this family and of the Hygrophoraceae can be recognised. It is not proposed to deal in detail with any individual members because they can be so easily confused with each other by the specialist let alone by the amateur.
However, the genera as at present accepted are as follows:—
1. Entoloma
in its original sense contains agarics with fleshy caps, fibrous stems and sinuate or adnexed gills, e.g. Ent. clypeatum (Fries) Kummer with grey to yellow-brown cap, found growing with members of the apple and rose-family in the summer and early autumn. This genus corresponds to Calocybe in the white-spored agarics ([p. 110]).