Jennings: Manual of Mossns— 15. Mniaceae 135 



1. Rhodobryum roseum (B. &: S.) Limpricht 



(Bryum onturiense Kindberg)* 

 Plate XXIV 



Gregarious to loosely cespitose, deep green: stems erect from long creeping 

 rhizome-like stolons, 2-5 cm high, stout, with minute appressed bract-like 

 leaves up to the summit, where the leaves suddenly enlarge to form a con- 

 spicuous rosette about 1 cm across; comal leaves numerous, obovate-spatulate 

 from a narrow base, the apex suddenly narrowed and acuminate and more or 

 less twisted, the margin revolute for about three-fourths the length of the leaf 

 and in the upper part prominently sharply spinulose dentate; costa strong, 

 ending below the apex but mostly plainly excurrent; leaf-cells rather large, 

 elongate-hexagonal, the walls medium, towards the base larger, thinner-walled, 

 more or less hyaline, rectangular: setae 1-3 to a perichaetium, erect, lustrous, 

 castaneous, 2-4 cm long: capsule pale brownish, oblong-cylindrical, about 4-5 

 mm long, incurved, somewhat constricted below the mouth when empty, at 

 the base having a narrow incurved collum about one-third the length of the 

 rest of the capsule, the capsule horizontal to sub-pendulous; peristome-teeth 

 large, linear-lanceolate, narrowly bordered, yellowish, hyaline and papillose 

 above, strongly trabeculate, lam.ellate with distinct divisural; segments about 

 four-fifths as long, carinately split and gaping; cilia 3, about as long as seg- 

 ments, strongly appendiculate; basal membiane about two-fifths the height of 

 teeth; spores yellowish, minutely roughened, about .020 mm; operculum convex- 

 apiculate; exothecial cells incrassate, rectangular to irregularly rounded, towards 

 the mouth in several rows very much smaller, very strongly incrassate and 

 darker; dioicous: mature in September and October. 



On rotten logs and rich humus in woods, sometimes on stones. South- 

 eastern Canada and northeastern United States. Rarely found in fruit. 



This interesting moss is now known from 12 counties in western Pennsylvania and 

 probably will be found in all. Specimen figured: Moon Twp., Allegheny Co., 1889. 

 J..A.S. 



Family 15. Mniaceae 



Synoicous or dioicous, rarely autoicous; male flowers disk-like with club- 

 shaped paraphyses: female flowers bud-like with filiform paraphyses: mostly 

 robust, cespitose: stem with a central strand, radiculose below, mostly erect, 

 frequently stoloniferous; comal leaves large and mostly spreading in a terminal 

 rosette, lower and stoloniferous leaves smaller and somewhat dissimilar: costa 

 strong, broad at base, tapering upwards and ending below or in the apez, rarely 

 toothed dorsally; cells parenchym.atous, mostly hexagonal or rounded, smooth, 

 uniform in size or gradually smaller in size, non-margined, costate: seta long, 

 stiff, smooth, mostly shortly hocked above; capsule mostly cernuous or pendent, 

 rarely erect, symmetric, oblong-ovoid to cylindric, rarely globose, sometimes 

 arcuate, collum short; annulus mostly biseriate and revoluble; peristome double 



* The American Rhodobryum ontanense (Kind.) Paris is supposed to differ from 

 R. roseum in that the latter has the costa ending below the apex of the leaf. Andrews, in 

 Grout's Moss Flora, is probably correct in not regarding our American plants as specifi- 

 cally different from the European R. roseum. 



