64 DICRANACE/E. 



3. Seligeria tristicha B. & S. (Weisia tristicha Brid. ; 

 Seligeria trifaria Lindb., Braithw. Br. M. Fl.) (Tab. XIII. G.) 



Plants resembling S. pusilla, but taller and more rigid, 1-2 

 lines high, slender, branched, brownish. Leaves regularly 

 imbricated in three rows, crowded, straight, erect, appressed 

 when dry, from a lanceolate concave base gradually narrowed to 

 a rigid, obtuse or acute, entire subula, composed of the nerve, 

 which is narrower at the base ; cells elongate- rectangular at 

 base, shorter above ; margin entire or very faintly sinuose. 

 Perichaetial bracts longer, the nerve more longly excurrent. 

 Capsule on an elongated seta, thick-walled, wide-mouthed and 

 hemispherical after the fall of the lid, with a long neck tapering 

 into the fruit stalk ; lid obliquely rostellate, rather long. 

 Peristome teeth sometimes perforated. 



Hab. Wet calcareous rocks. Very rare. Perthshire ; Yorkshire ; Derbyshire. 

 Fr. summer. 



The stems are often closely tufted, and sometimes very much branched ; the 

 leaves are rather brittle ; their regular arrangement giving the stems a. distinct and 

 peculiar trigonous appearance. The form of the capsule when ripe, together with its 

 neck, is regularly pyriform, the neck varying somewhat in length, sometimes very 

 gradually narrowing downwards. It is readily distinguished by the tall slender 

 stems, and the trifarious arrangement of the leaves. The wide pachydermous capsule, 

 the entire leaves, and narrow cells, are also characters of value, in cases where, 

 as occasionally happens, the tristichous leaf arrangement is not so distinct. 



4. Seligeria paucifolia Carruth. (Bryum paucifolium Dicks., 



S. subcernua Schp., Syn.) (Tab. XIII. H.) 



Plants gregarious, pale dull green, very short, unbranched. 

 Leaves crowded, the upper longer, sub-flexuose, longly and finely 

 subulate from a lanceolate, gradually narrowing base, quite 

 entire ; nerve very indistinct at base, gradually stronger, wide 

 above and sometimes very slightly excurrent ; cells rectangular, 

 shorter above, a single row on each side reaching almost or quite 

 to the apex ; seta erect, slightly flexuose above ; capsule thick- 

 walled, narrowly oval or oblong, sometimes slightly asymmetric, 

 narrowed at the mouth ; lid with an oblique subulate beak ; 

 peristome teeth narrow, lanceolate. 



Hab. Blocks of chalk ; rare. Fr. summer. 



The narrow elongated capsule, contracted, not expanded, at mouth, on an erect 

 seta, is the most distinguishing feature of this species. It seems to prefer detached 

 blocks of chalk rather than cliffs. 



