Phascum.] BRYACE^. 41 



obtusely tetragonal head, deeply concave, cuspidate by the 

 thick excurrent costa, denticulate or erose at the apex : male 

 buds sessile at the base of the fertile ones : capsule on an erect 

 flexuous or arcuate pedicel. — Acaulon ric/'escens, A. Jaegei-, 

 Muse. Cleist. 19. Acaulon triquetrum, var., Sulliv. & Lesq. 

 Muse. Bor.-Am. Exsicc. (2 ed.), n. 31. 



Hac. Very common in the Eastern and Central States. 



This species is intermediate between the last and tlie next following, 

 and so near to both that it is difficult to indicate a constant specific 

 character. The color of the more distinctly triangular perichsetium, as well 

 as the occasionally longer and curved pedicel, refers it to S. triquetruin ; 

 but in the generally short and straight pedicel, the leaves not at all or 

 scarcely revolate on the margin and more distinctly erose-denticulate at 

 the apex, and the bulb-like heads indistinctly triquetrous, it approaches 

 S. mutlcu)n. 



3. S. triquetrum, Schimp. Plants pale green or yellowish, 

 distinctly triquetrous : lower leaves small, somewhat nerveless, 

 the middle broadly ovate and costate, and the terminal deeply 

 carinate, rellexed on the margins, minutely erose at the apex, 

 mucronate by the excurrent recurved point of the costa : cap- 

 sule pendent from a longer arcuate pedicel. — Syn. Muse. 14. 

 Phascum triquetrum., Spruce, Engl. Bot. Suppl. t. 2901 ; Sulliv. 

 Mosses of TJ. States, 15. Acaulon triquetrum, Muell. Syn. ; 



Bryol. Eur., t. 4. 



Hak. Open soil; New England {Ingraham, James); New Jersey 

 {Austin); Santee Canal, South Carolina (Ravenel); Saskatchewan 

 {Druinmond). 



4, S. Schimperianum. Plants sparsely gi-eganous,ovoid- 

 bulbiform : leaves closely imbi'icate, the lower small, ecostate, 

 the upper much larger, deeply concave, recurved at the apex, 

 papillose on both faces, recurved on the margin, erose-dentate 

 in the u]iper part, the costa appearing below the apex and ex- 

 current into a long point : capsule globose, scarcely mamillate, 

 orange-colored, horizontally inclined by a curve of the some- 

 what long pedicel. — Phascum Schimperianum, Sitlliv. Mosses 

 of U. States, 15. Acaulon Schimperianum, Sulliv. Icon. Muse. 

 18, t. 9. 



Hab. San Marcos, Texas {Wriglit); Athens, Illinois [E. Hall). 



5. PHASCUM, Linn., in part. (PL 1.) 

 Plants more robust, distinctly caulescent. Leaves costate ; 

 cells of the areolation loose, hexagonal-rectangular and hyaline 



