TORTULA. 187 



17. Tortula intermedia Berk. (Syntrichia intermedia Brid. ; 

 Barbula intermedia Milde, Scrip. Syn. ; Tortula -montana Lindb., 



Braithw. Br. M. Fl.) (Tab. XXVIII. E.). 



Somewhat intermediate between T. Isevipila and T. ruralis ; 

 robust, in large tufts, dull or brownish green, hoary above, i-if 

 inches high. Leaves crowded, erecto-patent, straight or very 

 slightly recurved, flat or somewhat concave, incurved and 

 appressed when dry, the upper ones sometimes slightly spirally 

 twisted, variable in size, but usually smaller and shorter than in 

 T. ruralis, oblong-spathulate, very obtuse and even emarginate 

 at apex, margin less strongly recurved and only in the lower half ; 

 cells much smaller above, very dense and obscure, hardly distinct 

 at margin, which is verruculose, but less highly so than in T. 

 ruralis ; nerve strong, red, excurrent in a shorter, less toothed 

 arista. Capsule shorter than in that species, on a shorter seta ; 

 peristome also shorter. Dioicous. 



Hah. Calcareous rocks and soil ; frequent. Fr. spring. 



Differs from the last species, in addition to the characters there mentioned, in the 

 taller stems, the red nerve, the dioicous inflorescence, and the absence of any distinct 

 border in the upper part of the leaf. Forms of T. ruralis, when growing on walls or 

 stony ground, frequently resemble it, but are easily recognised by the more or less 

 squarrose leaves, the larger, more distinct cells, and more strongly recurved margin, 

 as well as by the more strongly toothed arista. 



When growing on the ground it is often of a rich golden brown colour. 



18. Tortula ruralis Ehrh. (Bryitm rurale L. ; Barbula 



ruralis Hedw., Schp. Syn.) (Tab. XXVIII. F.). 



In loose, tall cushions, 1-3 inches high, bright green above, 

 bright reddish brown below, robust ; stems branched. Leaves 

 less croivded, more so at the apex of the stems, squarrose- 

 recurved especially above, when dry appressed and slightly 

 twisted, with two longitudinal plicas which are faint when moist 

 but distinct when dry ; longly oblong-elliptical or oblong-spathu- 

 late, concave-carinate, at apex obtuse or emarginate, more rarely 

 acute ; margin reflexed almost to the summit ; nerve reddish, 

 muricate at back above, prominent behind, excurrent in a long, 

 flexuose, strongly spinulose arista which is hyaline above, often 

 reddish at base, sometimes equalling in length the rest of the leaf. 

 Cells at mid-base lax, rectangular, hyaline, towards margins 

 coloured, above rounded-hexagonal, strongly papillose, rather 

 obscure, the walls frequently brown and incrassate ; marginal 

 cells hardly distinct, strongly verruculose with coarse, bifid 

 papilla?. Seta long (about 1 inch) stout, reddish, capsule narrowly 



