Jennings: Manual of Mosses— 22. Polytrichaceae 165 



2. PoGONATUM Beauvois 



Dioicous: gregarious to weakly cespitose: fertile stems arising from a 

 creeping underground stem or from a radiculose protonema, erect, stiff, short 

 and simple or some longer and branched; leaves gradually longer upwards, 

 erect-spreading to recurved, more or less clasping at base, stiffened by mostly 

 numerous lamellae, especially towards the apex, the margins more or less dis- 

 tinctly spinulose, leaf-blade smooth dorsally, usually for the most part bi- 

 stratose; the lower part of costa narrow and plane, dorsally towards the apex 

 toothed; cells of the leaf-blade small, incrassate, in the unistratose border 

 mostly quadrate or transversely elongate, basal cells elongate to linear, yellow- 

 ish to hyaline, thinner walled: seta solitary, sometimes more, castaneous; cap- 

 sule erect, straight or curved, cylindrical, without stomata; peristome-teeth 32, 

 pale to yellowish-brown with a darker axis; operculum convex and more or less 

 long-rostrate; calyptra mitrate, densely hirsute, more or less shaggy. 



A large genus of about 160 species, growing on earth, widely distributed; 

 about 45 species reported for North America; only one species yet found in 

 our region. 



Key to the Species 



A. Leaf-margins entire; lamellae 25-35 (P. brachyphyllum [Richard] Schwaegrichen) * 



A. Leaf-margins more or less serrate; lamellae 10-15 pensilvanicum 



1. PoGONATUM PENSILVANICUM (Hedwig) Paris 



(Polytrichum pensilvanicum Hedwig; Pogonatum breyicaule 



Beauvois; P. tenue E. G. Britton) 



Plate XXXII 



Plants scattered on a green felt-like persistent protonema which covers the 

 moist, bare clay: stems very short, usually about 1-2 mm long; leaves lance- 

 olate-subulate, the lower shorter and more ovate, narrowing abruptly to an 

 acuminate apex, margins serrulate in the upper half; upper leaves lanceolate 

 with a long-acuminate, serrulate apex, appressed or somewhat spreading; lamel- 

 lae 10 to 15, 5 or 6 cells high, terminal cell orbicular to ovoid in cross-section, 

 smooth: seta slender, smooth, yellowish to reddish; calyptra light yellow, very 

 hairy and more or less shaggy, completely covering the capsule; capsule erect, 

 symmetric, long cylindric, minutely papillose, slightly or not at all constricted 

 below the lid, yellowish to reddish, about 4 mm x 0.8 mm; lid obtuse to trun- 

 cate, abruptly tipped with a beak about 0.4 mm long; spores maturing in our 

 region about November. 



A common moss on bare clay banks, especially if somewhat moist and 

 shaded, from Nova Scotia to Missouri and south to Alabama. 



Usually found on clay roadside banks where the soil is covered with the 

 dense felt of protonema above which are borne the sporophytes with their 

 light gray shaggy calyptra. 



Now known from 14 counties in western Pennsylvania and probably occurs in all. 

 Specimen; figured: Darlington Hollow, Allegheny Co., Oct. 12, 1908. O.E.J. &.' G.K.J. 



* On clay banks, from the Gulf States extending north to New Jersey and Penn- 

 sylvania. 



