GRIMMIA. 131 



-/Plant coarse and robust, cells mostly more or less sinuose 13*. robusta 



-•\Cells not (or scarcely) sinuose 26 



,/Ls. subsquarrose, hair roughish //. subsquarrosa 



\Ls. narrow, patent, point smooth 12. Stirtoni 



/Plant tall, dull-green ; upper cells opaque 14. elatior 



' \ Plant smaller, yellowish or greyish green 28 



o/Ls. spirally twisted when dry, narrow ; plant slender 6. funalis 



\Ls. scarcely twisted when dry, wider at base 10. trichophylla 



A. SCHISTIDIUM. 



Capsule immersed, on a short, erect seta, wide-mouthed ; 

 columella remaining attached to the lid when the latter falls. 



1. Grimmia apocarpa Hedw. (Bryum apocarpum L.) 

 (Tab. XXI. D.). 



Extremely variable in habit ; in its typical form it forms 

 rather loose, small tufts, with erect stems, about 1 inch high, of a 

 dull olive green or brownish colour. Leaves broadly ovate- 

 lanceolate, erecto-patent, erect when dry and forming a cuspidate 

 point at the top of the stem, carinate above, margin narrowly 

 recurved ; the point entire or obscurely notched ; nerve vanishing 

 at or below apex, slightly roughened behind, terete at back ; 

 hair-point variable, usually short, hardly \ length of leaf, slightly 

 rough, flattened, sometimes wanting ; lower cells rectangular, 

 rather short and firm, then quadrate, with the walls slightly 

 sinuose, in upper part small, rounded or quadrate-hexagonal, 

 incrassate, opaque. Pericha^tial bracts wider, thinner, with a 

 narrower nerve. Calyptra very small, not reaching below the lid, 

 lobed at the base. Capsule persistent, oval-oblong, rather thick- 

 walled, almost concealed by the perichstial leaves, reddish brown, 

 with a ring of stomata at the base, which are sometimes rather 

 indistinct ; bright red, straight or oblique, rostellate ; peristome 

 teeth inserted below the mouth, large, bright red, entire or 

 slightly perforated, rather solid, spreading when dry. Columella 

 attached to the lid and falling off with it. Autoicous. 



Var. (3. rivularis W. & M. (Grimmia rivularis Brid.). 

 Taller, 2-4 inches long, decumbent, denuded at base, much 

 branched, dull green or blackish ; leaves rather obtuse, often 

 secund, usually without a hyaline point ; capsule shorter, wider, 

 turbinate , paler. 



Var. y. gracilis W. & M. (Grimmia gracilis Schleich.). 

 Tall and slender, decumbent ; leaves spreading or secund, 

 denticulate above, usually hair-pointed ; perichaetial bracts and 

 capsule often slightly secund ; capsule oblong. 



