" 164 
2. Branch leaves serrate. 
S ooth. 
a. Capsule erect and symmetric. * 
Synoicous. 30. B. Utahense. 
Dioicous i 
Cilia single. 15. B. splendens. 
Cilia rudimentary or wantin: 
Plants slender ; leaves aditi slender pointed. 
16. B. biventrosum. 
Plants more robust ; leaves acuminate. I4. D. acuminatum. 
b. Capsules unsymmetric, more or less inclined. 
: : es 3-4: I, suberect. 
Monoicous ; enlarged basal cells very numerous and conspicuous. 
4. B. Roteanum. 
Dioicous ; only a few basal cells enlarged. 6. B. oxycladon. 
tt Capsules 2—3:1, strongly inclined or horizontal.t 
*Stem leaves gradually narrowed from base to slender apex. 
Plants robust ; leaves at least 1.8 mm. long. 
` Stem leaves lanceolate, 0.6 mm. broad. 2. B. flexicaule. 
Stem leaves triangular-ovate, I mm. broad. 5. B. acutum. 
Plants slender; branch leaves not more than 1.5 mm. long. 
8. B. pseudo-collinum. 
** Stem leaves acuminate. 
Dioicous. 31. B. erythrorrhizon. 
Monoicous. 
Branch leaves at least 1.8 mm. long. I. B. salebrosum. 
Branch leaves not more than 1.2 mm. long. 
St ves broadly ovate. 20. B. digastrum. 
Stem leaves narrowly ovate to ovate-lanceolate. 
Branch leaves oblong-lanceolate, 1-1.2 mm. long. 
28. B. suberythrorrhizon. 
Branch leaves ovate-lanceolate, less than 1 mm. long. 
gradually acuminate. 26. F pewter 
abruptly acuminate. 29. num. 
B. Seta slightly roughened with small pide pie 
Stems short, irregularly branching ; monoicous. 29. B. collin 
Stems long and slender, yeu branching; dioicous. 31. 7. wien Thedenii, 
ugh above, nearly smooth below. 
Leaves d long icum 3. B. campestre. 
s not pie shorter acuminate. 18. B. plumosum. 
D. Seta h throughout, with large oie papillae. 
Cells of branch leaves 5 : I, unipapillate. D NA tactics. 
Cells of branch necis at least 8: 1, smooth. 
Secon: ems dendroid ; leaves ovate and very short-acuminate. 
13. B. rivulare. 
* B. cyrtophyllum belongs here. 
T Capsules of B. flexicaule are sometimes 3-4:1. 
