438 
IV. MUSCI. 
\Bryum. 
B. Plants perennial Bryum. 
I. Upper leaves larger, spreading (except in B. campylothecium), rosulate, more or less 
serrulate. 
Upper leaves spreading ; margin thickened 2. B. truncorum. 
Upper leaves erect, lanceolate ; margin hardly thickened ... 3. B. campylothecium. 
Upper leaves spreading, ovate-oblong; margin not thickened . . 4. B. Billardierii. 
Upper leaves spreading, spathulate ; margin not thickened . . . 5. B. rufescens. 
II. Upper leaves not larger and spreading , distinctly serrulate (except in B. eximium). 
a. Nerve vanishing below the apex of the leaf. 
Lower leaves ovate-acuminate 6. B. Wahlenbergii. 
Lower leaves lanceolate 7. B. crudum. 
i8. Nerve percurrent or excurrent. 
Leaves ^ in. long 8. B. eximium. 
Leaves small, oblong-ovate, not crisped when dry. Inflo- 
rescence dioecious 9. B. obconicv.m. 
Leaves small, oblong-ovate, crisped when dry. Inflorescence 
dioecious 10. B. Icevigatum. 
Leaves small, upper narrow-lanceolate. Inflorescence monoe- 
cious 11. B. nutans. 
III. Upper leaves not large and spreading, quite entire or very obscurely serrulate. 
a. Leaves white and silvery 12. B. argenteum. 
0. Leaves green, very obtuse 13. B. blandum. 
y. Leaves green, subulate-lanceolate 14. B. tenuifolium. 
y. Leaves ovate or ovate-lanceolate or oblong-lanceolate , acute or acuminate, not white or 
silvery, nerve excurrent or percurrent. 
t Inflorescence hermaphrodite. 
Leaves ovate-lanceolate 15. B. bimum. 
Leaves lanceolate, keeled, much crisped when dry . . . 16. B. torquescens. 
Leaves oblong ; cells large, soft 17. B. mucronatum. 
++ Inflorescence dioecious. 
§ Capsule cylindric, clavateor long-pyriform. 
Leaves erecto-patent, oblong, cuspidate ; nerve stout, ex- 
current 18. B. curvicollum. 
Leaves suberect, lanceolate ; nerve slender, excurrent in a 
hair-point 19.5. creberrimum. 
Leaves appressed, ovate-oblong ; nerve short .... 20. B. crassum. 
Leaves erecto-patent, ovate-lanceolate. Operculum large, 
mamillate 21. 15. coespiticium. 
Leaves erecto-patent, oblong-lanceolate. Operculum 
shortly conical, apiculate 22. B. chrysoneuron. 
§§ Capsule short, oblong or pyriform. 
Capsule pyriform 23. B. annulatum. 
Capsule ventricose, depressed at base. Leaf-margin flat 24. B. pachytheca. 
Capsule ovate-oblong, rounded at base. Leaf-margiu re- 
curved 25. B. atro-purpureum. 
OF DUBIOUS SECTION. 
B. flaccidum, B. varium, B. intermedium, B. incurvifolium. 
1. B. pyriforme, Hedwig. Tufts annual or perennial, forming broad 
silky patches, bright green. Stems simple, slender, rooting at base only. 
Lower leaves lanceolate, entire, upper linear-setaceous, flexuous, slightly 
serrate ; nerve extending almost to the apex ; cells oblong. Fruitstalk 
slender, flexuous. Capsule inclined or pendulous, pyriform, thin in texture ; 
mouth small ; operculum convex. — feptobryum, Wils. Bryol. Brit. 220. t. 28 ; 
FI. Tasm. ii. 188. 
