154 DIPLOPERISTOMI. \_Hypnum. 



Hypnum denticulatum. /3. obtusifolium. Turn. Muse. Hib. p. 146. 

 t. 12. f. 2. 



Hypnum obtusatum. Wahl. Fl. Lapp. p. 371. 



Hypnum Donianum. Engl. Bot. t. 1446. 



Hypnum obtusifolium. JBrid. Meth. p. 153. 



HAB. Principally in woods, ft. among the mountains. 

 This species varies extremely in its size, somewhat in colour, 

 and greatly in the figure, and even in the texture of the leaves. 

 In our a, the most common state of the plant, the leaves are almost 

 exactly distichous, horizontal, narrow, and acuminate, so distant 

 as to resemble teeth set along the stem, and better agreeing with 

 the Dillenian figures than with those of Hedwig, which perhaps 

 more properly belong to our /3. In this the leaves are broader, 

 more concave and obtuse, less truly distichous, and their struc- 

 ture is, under the microscope, more reticulated. This is the 

 var. y. obtusifolium of Turner, and H. obtusatum of Wahlenberg, 

 and the H. Donianum of Smith. We would gladly follow the 

 two last named able Botanists in keeping this distinct as a 

 species from a. did we not possess specimens in an intermediate 

 state, both with regard to the form of the leaf, its reticulated 

 structure, and even the direction of the foliage. All coincide 

 in having the same, almost cylindraceous, inclined capsule, and 

 conical lid, and in having a short, forked, or double nerve. 



II. Stems, (taken in conjunction with the leaves,) more or less 

 cylindrical, never plane. 



1. Leaves spreading on all sides of the stem.\\ 



A. Leaves uniform in their direction, (not squarrose.) 



a. Nerve reaching to, or beyond the point. 



* Leaves without serratures. 



6. H. medium ; leaves ovate obtuse concave entire slightly falca- 

 to-secund nerve reaching to the summit, capsule cylindrical 

 nearly erect, lid conical. (TAB. XXIV.) 



Hypnum medium. Dicks. Crypt. Fasc. 2. p. 12. Turn. Muse. Hib. 



|| In opposition to "leaves secund." 



