106 HYPXACEAE 



collenchymatous (i. e., strongly nodulose at points of intersec- 

 tion), in all our species except Novae--Caesareae. This genus 

 differs from Hypnum, subgenus Psendo-Raphidostegium, in the 

 lack of paraphyllia, less falcate and scarcely »ecund or serrate 

 leaves, and in the characteristic cell walls of the capsules. All 

 southern, reaching our range as a northern limit. The leaves 

 described in this genus are from the middle of the branches. 



I — Plants growing on trees, of Pylaisia habit; capsules erect and sym- 

 metric or nearly so adnatmn 



Plants growing on rocks and stones, capsules inclined to horizontal. . . .2 



2 — Leaves suborbicular, serrate Xovae-Caesareae 



Leaves oblong-ovate to oblong-lanceolate; entire or slightly serrulate. 



Carolinian nm 



R. adnatum (Mx.) B. & S. {Hypnum microcarpum L. & J. 

 Manual). Bark of living trees. Summer -autumn. Jamaica!! 

 & New Lots, Brainerd (26782)!, L. Id. 



R. carolinianum (C. M.) J. & S. "On damp shaded rock in 

 mountainous regions, Palisades (very rare)," Muse. App. 338 

 (as Rhynchostegium demission); "On stones in damp woods 

 about Closter, X. J. Frequent," Muse. App. 339 (as R. micro- 

 carpum var. anisocarpon) ; near Mausoleum pumping Station, 

 S. Id., E. G. B., Bx!; Palisades, X. J. and Bronx Park, Wieg- 

 mann. 



Var. admixtum (Sulliv.) Grout. Bronx Park, E. G. B. 



R. novae-caesareae (Aust.) R. & C. "On rocks in a small 

 rivulet which crosses the 'State Line' between Shawangunk 

 Mountains near High Point, sterile," Muse. App. 440. 



PLAGIOTHECIUM B. & S. 



Mostly loosely tufted glossy mosses, growing on moist stones 

 and earth, roots of trees and decaying wood; irregularly branch- 

 ing; stems and branches appearing flattened by reason of the 

 complanate leaves (except in Roeseanum, pidcheUum and stria- 

 lellum). The twisting to the sides makes some of the leaves 

 unsymmetrical, (except in the species named above) but other- 

 wise they are symmetrical. Stems and branches often ending 

 in flagella or stolons; paraphyllia lacking. Stem and branch 



