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IV.— On Bog Mosses. By R. Braithwaite, M.D., F.L.S. 



Group A, addenda. 



6. Sphagnum papillosum Lindberg. 



Contrib. ad Fl. Crypt. Asia; Bor-Or. p. 280 (1872). 

 Plates XVI. and XVII. 



Syn. — Sph. Cymbifolium p. p. omnium auctorum. 



Dioicous; more or less ochraceous or brown, never tinged 

 with purple ; base of stem-leaves and bracts, as also the points of 

 branch leaves, darker brown. Stems more slender than those of 

 S. cymbifolium, reddish-brown ; bark composed of 4 strata of cells, 

 the outer perforated by several large foramina, but without fibres, 

 the others with very fine spiral fibres. Branches 3-4 in a fascicle, 

 2 divergent, short, acute; 1-2 pendent, appressed to stein, atten- 

 uated ; cortical cells, with fine spiral fibres and large pores. 

 Cauline leaves rather rigid, spathulate, minutely fringed at apex, 

 their cells large, empty below, with a few fibres and pores above. 



Ramuline leaves closely imbricated, strongly cymbiform-concave, 

 cucullate at apex, very broadly ovate, obtuse, cells large, the hyaline 

 filled with spiral fibres and perforated by large pores, their walls 

 combined with those of the chlorophyll cells, and there covered in- 

 ternally with minute short papillse ; chlorophyll cells central, ellip- 

 tical. Male plants more slender, amentula more or less ochraceous, 

 short, ovate, pointed, the bracts broadly ovate, concave, obtuse, 

 the margin minutely fringed toward the apex, the areolation Like 

 that of the branch leaves. Fruit not greatly exserted ; peduncular 

 bracts large, oblong, convolute, plicate, the cells very large and 

 of two forms ; in the lower half of the bract, the central part con- 

 sists of narrow parenchymatous empty cells, ivith thick walls, 

 the margins and the upper half of the bract of normal porose and 



EXPLANATION OF PLATE XVI. 



Sphagnum papillosum. 



a. — Female plant, a <?. — Part of male plant. 



1. — Part of stem with a branch fascicle. 



2. — Catkin of male flowers. 2 6. — Bract from same. 



3. — Fruit with its peduncle. 



4. — Peduncular leaf. 4 b a. — Areolation of basal wing of same. 



5. — Stem leaf. 



6. — Branch leaf. 6 p. — Point of same. 6x. — Transverse section of same. 6 a a. — 

 Areolation of half of apex of same, expanded under pressure. 6 c. — Single 

 cell x 200. 6 y. — Branch leaf of the var. Stenophyllum. 



7. — Intermediate leaves from base of a divergent branch. 



9 x. — Part of transverse section of stem. 9 c. — Outer cortical cells of stem. 



N.B. — The dotted line in Fig. 4 indicates the parts occupied by the two 

 kinds of cells. 



