198 TORTULACE/E. 



9. Barbula gracilis Schwgr. (B. acuta Brid., Braithw. 

 Br. M. Fl.) (Tab. XXIX. K.). 



Short, \-\ inch high, in dense tufts, olive green, frequently 

 becoming brown. Stems straight, rather rigid ; leaves small, 

 straight, erecto-patent, appressed when dry and very slightly 

 twisted, from an ovate base, gradually but quickly tapering to an 

 acute point, concave; margin widely reflexed below, plane above, 

 nerve strong, reddish, forming the greater part of the leaf point r 

 and in the upper leaves at least excurrent in a short red acute 

 mucro ; cells small, rounded, distinct, incrassate, smooth or 

 slightly papillose, at base small, shortly rectangular. Peri- 

 chaetial bracts wide, sub-sheathing, the nerve more longly 

 excurrent in a somewhat flexuose point. Capsule oval-oblong, 

 small, short; lid long, slender; peristome short, slightly twisted. 

 Dioicous. 



Hab. Walls and bare places in warm situations. Very rare, and sterile ; near 

 Bristol ; Jersey. 



Somewhat resembling small forms of B. fallax. The leaves, however, are 

 shorter, straighter, and more erect, the basal angles more distinctly rectangular. It 

 is still more like B. rigidula, and there is little in the barren state to distinguish 

 them, but the more distinct rounded cells in the present plant, with the nerve usually 

 distinctly excurrent in some of the leaves, and the perichaetial bracts especially long- 

 cuspidate and flexuose. B. Hornschuchiana has the leaves less narrowly tapering, 

 the margin more distinctly revolute, and the nerve stouter and more clearly excurrent. 

 The next species is the most closely allied, but differs in the more suddenly narrowed 

 leaves with longer, finer acumen and more excurrent nerve. The margin in both 

 species is rather widely but not strongly reflexed, like the side of a dish, the extreme 

 edge being in addition irregularly and more narrowly revolute. 



10. Barbula icmadophila Schp. (Braithw. Br. M. Fl., 

 Vol. II., Suppl.) (Tab. XXIX. L.). 



Taller and more slender, \-2\ inches high. Leaves more 

 suddenly contracted to a narrow, almost subulate acumen, the 

 greater part formed by the longly excurrent nerve ; cells a little 

 larger, very distinct, more quadrate or angular. Capsule 

 narrowly elliptical. 



Hab. Wet rocks, frequently on mountains. Very rare ; Skye ; Ben Lawers. 

 Sterile. Fr. late summer. 



Very near the last species, but quite distinct in the longly excurrent nerve, the 

 more angular areolation, and the longer, narrower capsule. The alpine form, which 

 is represented by the Ben Lawers plant, is short, very dense, and always barren. 

 The fruit has been found in the Tyrol. 



