Jennings: Manual of Mosses— 22. Polytrichaceae 163 



Occurring on wooded shaly or clayey banks; Europe, Asia, and, in North 

 America, from Newfoundland and Ontario to the Gulf States. In our region 

 not very common, seemingly preferring steep slopes of ravines, and there often 

 under hemlocks. Quite variable and often approaching closely the two species 

 next following. 



Now known from the following counties: Allegheny, Armstrong, Beaver, Butler, Craw- 

 ford, Ene, Greene. Lawrence, McKean, Washington, and Westmoreland. Specimen fig- 

 ured: Hartstown, Crawford County, May 29-31, 1909. O.E.J. 



4. Atrichum papillosum (Jennings) Frye* 



(Catharinaea papillosa Jennmgs) 

 Plate XXXI 



Plants loosely cespitose, dark green, dioicous: stems simple or at the base 

 sparsely branched, towards the base radiculose, erect, about 2 cm high, chest- 

 nut-brown to purple; lower leaves dark green, short, oblong, above gradually 

 longer, erect-spreading, the upper leaves tufted, erect-spreading to erect, oblong- 

 linear, 3-5 mm. long, 0.7-1.0 mm wide, margined, above chlorophyll-bearing, 

 obtuse to somewhat acute, towards the apex dorsally serrate-spinulose, in the 

 margin above the middle more or less doubly serrate-spinulose, when moistened 

 slightly undulate, when dry crisped and circinate, lamellate ventrally along 

 the percurrent costa; lamellae 4-8, mostly 6-14 cells high, smooth or minutely 

 and sparsely papillose above the middle, extending over 1/5 to 1/3 the median 

 width of the leaf; leaf-cells on both sides usually slightly minutely papillose, 

 the lower cells hyaline, hexagonal-rectangular, about 10-15 by .030-. 045 mm, 

 the median more or less quadrate, the upper cells quadrate-orbicular, chloro- 

 phyll-bearing, about .008-.015 mm, the lower border cells linear, incrassate, in 

 two to three series, more or less two-layered, towards the apex gradually becom- 

 ing rectangular, in the teeth triangular and sometimes .125-. 140 mm long; 

 perichaetial leaves similar to the stem-leaves; the perigonial leaves of the 

 antheridial plants from an ovate-orbicular concave base abruptly linear-acumin- 

 ate, about 2 mm wide and 3 mm. long, towards the apex canaliculte, lam.ellate 

 marginally and dorsally serrate-spinulose and usually sparsely papillose; lamel- 

 lae usually papillose, 4-6, only 3-7 cells high, disappearing quickly below the 

 base of the acumen: flowers dioicous or rarely arising from the center of the 

 masculine flower of the preceding year: seta solitary, erect, flexuous, slightly 

 sinistrorse, about 2 cm long, smooth, sub-lustrous, chestnut-brown; capsule 

 linear-cylindric, 3.5-6 mm long, 0.5-0.7 mm in diameter, erect-arcuate, tapering 

 abruptly at the base, smooth, chestnut-brown; cells of the capsule rectangular, 

 their lateral walls much incrassate, in a series of 5 or 6 cells under the mouth 

 smaller, quadrate, dark-incrassate; peristome teeth 32, linear-oblong, about 0.3 

 mm. high, in the median line reddish-orange, towards the sides hyaline, in the 

 margins a little dark and densely although minutely papillose, forming a basal 

 membrane in the lower third; spores smooth, incrassate, orange-pellucid, glo- 

 bose, about .COS-. 01 1 mm; calyptra about 5 mm long, narrowly cucullate, 



* Grout (Moss Flora 1: 251. 1939) regards this as synonymous with A. Macmillani 

 (Holz) Frye, of eastern United States, common in the southeast. 



