HYPNUM. 485 



Var. ji. Mackayi Schp. More robust, less soft. Leaves 

 imbricated all round the stem, not or scarcely secund, larger ; 

 auricles less clearly defined. 



Hab. Rocks in mountain streams, not common. The var. £ in similar situa- 

 tions, and apparently as widely distributed. Fr. summer. 



The very clearly defined, small, highly coloured auricles at once distinguish this 

 species ; in the young leaves they are hyaline, but soon, the inner ones at first, 

 become orange, gradually deepening in colour until in the older leaves they are of a 

 rich sienna hue and quite opaque with the colouring matter, though free from granular 

 ■contents. The leaves too are very constant in form, and the apiculate summit is very 

 .characteristic. The var. Mackayi does not appear to be very clearly marked off from 

 the type, the characters given being none too constant. The less clear definition of 

 the auricles does not, at any rate always, arise from the cells being smaller, but from 

 the intervention of one or two series of obscure, incrassate, more or less coloured 

 cells which form a more graduated step from the rest of the leaf-tissue. In its tall 

 forms this variety bears a considerable resemblance, when growing, to Brachythecium 

 plumosum, with which it is frequently mixed, bnt the shortly pointed leaves can be 

 ■easily recognised with the lens. 



31. Hypnum OChraceum Turn. (Amblystegium ochraceum 

 Lindb.) (Tab. LIX. G.). 



Very variable, often simulating species of the Section 

 Harpidium, or others of the present Section. Stems prostrate, 

 2-4 inches long, with irregularly pinnate, few, ascending or 

 procumbent, parallel branches, rarely more erect and curved, 

 soft and flaccid, in dense large tufts, pale green, usually with a 

 yellowish colour, rusty red, or deep brown, most frequently 

 yellowish. Leaves sub-secund, usually strongly falcato-secund, 

 concave, more or less widely oblong-lanceolate from a slightly 

 rounded base, tapering to a longer or shorter, wide, obtuse or sub- 

 obtuse acumen , which is often somewhat twisted; lightly plicate, 

 entire, except at the minutely denticulate apex ; nerve variable, 

 short and double or single and reaching half way or more. Cells 

 linear-vermicular, narrow, 8-15 times as long as wide ; angular 

 very large, thin-walled, hyaline, forming rather well-defined and 

 large, very conspicuous , hyaline, decurrent auricles. Dioicous. 



Var. ji.flaccidum Milde. Leaves straighter, not falcate, not 

 or hardly secund ; leaves narrow, longly acuminate , slightly 

 crisped when dry. 



Hab. Rocks in mountain streams, frequent in mountain districts. The var. /3 ; 

 Yorkshire. Fr. summer, very rare. 



A polymorphous plant, mostly resembling forms of H. palustre, but usually 

 longer, softer, and more brightly coloured ; and quite distinct in the large hyaline 

 .auricular cells, which, with the form of the leaf will also distinguish it from the other 

 allied species. Its soft, flaccid texture is a fairly constant and reliable character. 



