Species of Heterocladium 125 



it 



U. S. Nat. Hb. 138 as H. 

 U. S. Nat. Hb. Plants o 



H. p. 



H. aberrans. 



Holzinger & Blake, Plants of N. W. Montana 47. 



The characters of H. procurrens are fairly constant and well 

 marked. The leaves, sub-shining and spreading, wet or dry, make 

 its recognition easy. In a few specimens the leaves when dry 

 were erect-spreading but when moistened became spreading. I 

 am indebted to Dr. Mitten for a portion of the type. 



2. Heterocladium squarrosulum (Voit) Lindb. Muse. Scand. 37. 



1879 



Hypmim sqitarrosiduni in Sturm D. Fl. 2, fasc. n. 1810. 

 Hypnum dimorphitm Brid. Spec. Muse. 2 : 149.1812. Lesq. 

 & James, Manual Mosses N. Am. 321. 1884. 



Heterocladium dimorphum Bry. Eur. fasc. 49-51. /. jyg. 1852. 



Plants rather small, in thin spreading tufts, pale yellowish 

 green, rarely deep green. Stems, with rudimentary central strand, 

 3—6 cm. long, stoloniform, radiculose, irregularly branched ; smaller 

 branches simple, larger (secondary stems) pinnate, rarely bipinnate ; 

 paraphyllia multiform, roundish ovate to narrowly lanceolate, ser- 

 rate ; leaves of primary stems variable, the lower often rudimen- 

 tary, the upper obscurely two-ranked, papillose, subsc ariose, .5-. 7 



mm. wide, .7-. 9 mm. long, costa short, thin, divided or bicostate, 

 not rarely obsolete ; from a decurrent, cordate, subclasping base 

 broadly round-ovate, abruptly subfiliform acuminate, spreading 

 recurved, margins plane, crenulate-serrulate ; leaves of the secon- 

 dary stems loosely appressed-imbricated when dry, erect-spread- 

 ing when moist, broadly ovate, serrulate, obtuse to short acumi- 

 nate ; ultimate branch leaves roundish ovate, rounded-obtuse, 

 rarely subacute ; leaf cells of the basal-central area of primary 

 stems nearly smooth, clear, linear, about .006 mm. wide, 3-6 

 times as long, in some passing through the middle into the acu- 

 men, in others surrounded by a broad border of shorter cells,, 

 varying from roundish quadrate to oblong-oval, with a subcentral 

 papilla on both surfaces ; leaf cells of the branch leaves similar,, 

 those of the basal-central area shorter, the border cells sometimes 

 hexagonal -quadrate. Dioicous ; perichetial bracts radiculose at 

 base, scariose, flexuose-spreading, long acuminate, serrate, inner 

 obscurely costate ; pedicels smooth, flexuose, about 1.5 cm. long ;. 

 capsule curved, horizontal, short-necked, pachydermous, con- 

 stricted below mouth when deoperculate ; urn 1.5 mm. long,. 



