﻿New American Hepaticae. 



By Marshall A. Howe. 



(Plates 336, 337.) 



SCAPANIA (?) HETEROPHVLLA. 



Plants obscurely complanate, dark green, often bleaching at 

 apices on drying, erect or ascending, forming compact cushions : 

 stems 4-6 cm. high from a rhizomatous base, rigid, fastigiately and 

 subdichotomously branched, brown, becoming almost black, nearly 

 or wholly destitute of root-hairs, denudate below, 20-30 cells in 

 thickness : leaves scarcely increasing in size upward, sometimes 

 smaller at the stem-apex, the upper erecto-patent, subimbricate, 

 the lower approximate, more spreading, often with squarrose tips, 

 all strongly undulate-crisped both when moist and when dry, 

 bilobed to the middle or bipartite, complicate, the carina acute or 

 somewhat rounded, but never winged, the lobes sometimes almost 

 disunited ; now and then with an unlobed leaf irregularly interpo- 

 lated, most frequently in the position of an underleaf ; margins of 

 the lower leaves commonly erose, of the upper entire or sparingly 

 denticulate ; ventral lobes twice as large as the dorsal or subequal, 

 1.7-2.5 mm. in length, .85-1.6 mm. in maximum width, broadly 

 obovate, elliptical, or obovate-oblong, usually decurrent, mostly 

 rounded-obtuse at apex ; dorsal lobes obtuse, obliquely and 

 broadly ovate or elliptical, not decurrent, sometimes appressed at 

 stem-apex, especially on the younger shoots, but mostly ascend- 

 ing or slightly squarrose-reflexed : leaf-cells generally opaque, with 

 smooth or slightly roughened cuticle, near the margin subquadrate 

 or roundish-hexagonal, 16-28 u, near the base oblong, 60—90 ft x 

 5-30 /*; trigones indistinct or wanting: remaining parts un- 

 known. (Plate 336.) 



On submerged stones in a cold mountain stream (alt. 3500 ft.) 



in company with CJiiloscypJius polyanthos rivnlaris and Porella 



rivularis, Sisson, Siskiyou Co., California, July, 1894 (Howe, no. 



34). 



The stream, which is formed by a great spring beside the rail- 

 way track about three-fourths of a mile north of the village of 

 Sisson, is said to maintain nearly a uniform volume throughout the 

 year, and as the plants were found wholly under water in the last 



( 183 ) 



