BARNES — NORTH AMERICAN MOSSES. 233 



THUIDIUM, p. 321. 



I. Plants small (to 5 cm.), delicate, creeping, 1~S pinnate. 



Costa of stem leaves wide {\ leaf base). 

 Branches papillate, leaf cells Q/j. diam. . . T. pygmaenm, 322. 



Branches papillate, leaf cells 9/U, longer at margin T. minntnlum, 322. 

 Costa of stem leaves narrow (j^j leaf base). 

 Leaf cells with several minute papillae . . . T. scitnm,^ 323. 

 Leaf cells with one papilla (rarely two). 

 Branch leaves roundish ovate, short acuminate T. Virginiannm,' 324. 

 Branch leaves ovate lanceolate, long acuminate T. microphyllum,' 324. 



II. Plants larger {to 10 cm.), creeping, 1-3 pinnate, forming exten- 

 sive flat mats. (Ill) 



Perichaetial leaves ciliate, costa of stem leaves not reach- 

 ing point T. delicatnlnm, 325. 



PerichaBtial leaves not ciliate. 



Oosta of stem leaves filling point . . . T. recognitum, 325. 



Costa of stem leaves % length T. Philiberti, 443a. 



[T, paludosum may be sought here.] 



III. Plants large {to 10 cm.), erect or ascending, 1-pinnate, in 

 wide tufts. 

 Leaf cells roundish or oblong (1 : 1-2), strongly papillose 



both sides T. abietinnm, 326. 



Leaf cells long rhombic to linear (1 : 3-6), smooth above. 



Stem leaves soft, sub-clasping, decurrent . . T. Blandovii, 326. 

 Stem leaves rigid, plicate-striate, sub-decurrent T. paludosum,* 330. 



This genus has been revised by G. N. Best, Bull. Torr. Bot. Club 23: 

 78-90. 1896, and we have been able to avail ourselves of his suggestions 

 by recalling MS. T. tamariscinum, Hedw. and T. remotifolium Grev. 

 Are not N. American; T. ereetum Duby = T. delicatulum L.; H. calyp- 

 tratum Sull. = T. microphyllum (Sw.) Best, an earlier name for fi". grra- 

 ej7e B. & S., and to it T. lignicola Kindb. is referred as a variety; T. Al- 

 leni Aust. is probably a sterile form of T. delicatulum L. 



1 See Appendix, no. 441. Not recognized by Best. 



^ T. Yirginianum (Brid.) Lindb. = Hypnum gradle Lancastriense S. & L., L. J. 

 Man. 324. 



^ T. microphyllum (Sw.) Best = Bypnum graeile B. & S., L. & J. Man, 324. See also 

 Appendix, no. 442. 



' T. paludosum (Sull.) Eau & Hervey = Bypnum. paludosum SuU., L. & J. Man. 330. 

 See also Appendix, no. 443. 



