212 American Midland Naturalist Monograph No. 6 



suberect, tapering at base; annulus distinct; operculum long-conic, acute; 

 spores in spring. 



Mostly in dry places, on earth, stones, or rocks, especially in calcareous 

 habitats. Arctic America south to Virginia and Colorado. Collected by Por- 

 ter on a cliff near Easton, Pa. 



4. Thuidium recognitum [Hedwig] Lindberg 



{Hypnum recognitum Hedwig; T. delkatidum Bryologia Europaea) 



Plate XL 



Yellowish-green, not as bright-colored as some of the other Thuidiums, 

 quite similar to the preceding but mostly bipinnate: the primary branches are 

 nearly equal in length, thus making the general outline of the frond more 

 linear-oblong; stem-leaves usually about 0.6 to 0.8 mm long, broadly triangu- 

 lar, auriculate-cordate, abruptly acuminate, recurved-spreading when moist, 

 the apex acute and often very slender, the serrulate margins usually plane, the 

 leaves sulcate when dry; costa sub-percurrent, somewhat broadened at apex; 

 leaf-cells incrassate, and each with a long, slender, upcurved dorsal papilla, the 

 median rhombic-oblong to rounded-quadrate, the apical somewhat narrower; 

 branch-leaves with apical cells with 2-4 papillae; perichaetial leaves up to 4.5 

 mm long, slenderly long-acuminate, non-ciliate: seta about 2-2.5 cm long, 

 slender, castaneous, lustrous, dextrorse above; capsule oblong-cylindric, arcuate, 

 more or less inclined, the urn castaneous, 2.5-3 mm long, when dry quite 

 sharply bent and constricted at the mouth; peristome as in T. dehcatulum; 

 annulus large, deciduous, pluri-seriate; lid short- rostrate; spores with yellowish, 

 medium-thick, granular walls, about .012-.014 mm, mature in midsummer. 



On the ground on rocks or on rotten wood in moist, shaded woods; 



Europe, Asia, northern Africa, and from northern Canada southeastward 



to Florida. 



Allegheny Co.: On clay bank under hemlocks, Wildwood Road Hollow, March 

 29, 1908. O.E.J, and G.K.J.; Guyasuta Hollow, October 25, 1908. O.E.J. Armstrong 

 Co.: Kittanning, September 24, 1904. O.E.J, (figured). Clinton Co.: Between Reno- 

 vo and Haneyville, July 15, 1908. O.E.J. Erie Co.: Moist woods. Presque Isle. Nelle 

 Ammons. July 2, 1935. McKean Co.: Langmade Hollow, May 3, 1896, Toad Hollow, 

 June 17, 1896, and Bolivar Run, July 17, 1897, all near Bradford. D.A.B. Washing- 

 ton Co.: On base of beech tree. Claysville. Linn &C Simonton. Dec. 17, 1892. 



5. Thuidium Alleni Austin 



Forming rather loose and thick, wide mats; stems more or less ascending, 

 somewhat irregularly bipinnate; paraphyllia numerous; stem-leaves ovate, 

 broadly acuminate, with apex acute to obtuse, sometimes more slenderly taper- 

 ing; margins of leaves crenulate-papillose; costate to well above the middle; 

 on each surface; paraphyllia few or none on branches; branch-leaves acuminate 

 median leaf -cells incrassate, rather oblong, 1-2:1, with one or more low papillae 

 from a concave, broadly ovate base, acute to obtuse; perichaetial leaves not 

 ciliate. According to Grout {Moss Flora) abundant in Florida. Reported 

 from other states as far north as Pennsylvania and Connecticut. "Mature 

 sporophytes unknown" ^ — Grout. 



