HvPNACEiE.] 36 [Amblystegium. 



Hab. — Near Newton viaduct, Warrington (Wilson) \\ Near York (Spruce). 

 Copgrove, Yorks. (Rev. J. Dalton). Near Airth {Lyle). Stratfor,d-on- 

 Avon [Bagnall). Arklow (Moore). 



This moss resembles both A . stellatum and A . riparium, and is at once 

 known from the former by the distinct nerve and different areolation of the 

 ascending leaves, and from the latter by the different leaf-base and cells, 

 and scariose texture. 



Sect. 3. DREPANOCLADUS C. Muell. (1851). Stems pinnate or 

 vaguely branched, both stem and branches uncinate at apex. Leaves 

 distinctly falcato-uncinate, with a single nerve, the cells elongate, linear. 



This section, rechristened Harpidium by Sullivant in 1856, is a most 

 difficult one to arrange, on account of the different views as to the value of 

 the species, held by different authors. Sanio has treated some of these as 

 hybrids, some as subspecies and forms, and Renauld in Husnot's Muscologia 

 gallica has added a large number of forms and varieties, these being the 

 result of an exhaustive examination of specimens from many authors demand 

 our attentive consideration. I have preferred the older arrangement of 

 Schimper and Lindberg, as leading us more readily to the identification of 

 specimens, which undoubtedly, as in other aquatic mosses, vary considerably. 



Clavis to the Species. 



Leaves longitudinally sulcate when moist. 

 Leaves auricled minutely denticulate. 



Dioicous, stem densely radiculose ; leaves deltoid at base. glaucum. 



without radicles ; leaves ovate at base. falcatum. 



Autoicous, leaves narrow at base. aduncum. 



Leaves not auricled, entire. vernicosum. 



Leaves not sulcate when moist. 

 Leaves auricled. 

 Angular cells incrassate, yellowish. Sendtneri. 



— ■ — inflated, hyaline. 



Leaves longly lane, denticulate, nerved into acumen. 



Dioicous, leaves falcaio-secund, faintly plicate. exannulatum. 



Autoicous, stem-leaves flexuose, only secund at top. fluitans. 



Leaves ovato-lanceolate, entire, nerved to f length. Kneiffii. 



Leaves not auricled. 



Robust, leaves densely crowded, wide, concave. 



Leaves hardly hooked, rugulose when dry. lycopodioides. 



strongly circinate, not altered by drying. revolvens. 



Slender, leaves twisted when dry, acumen short, cells shorter. intermedium. 



19. AMBLYSTEGIUM GLAUCUM (Lam.) Lindb. 



Dioicous ; stem ascending, pinnate, radiculose. Leaves secund, 

 circinate, spreading, cordate and ovato-lanc, acuminate, plicato-striate, 

 subserrulate, nerved above half-way. Caps, oblong cernuous, lid 

 conical. (T. XCI, B.) 



Syn. — Hypnum repens fiUcinum crispum Dill, in Fay Synops. 3 ed. 85, n. 32 (1724), Hist, 

 muse. 282, t. 36, f. 19 (1741) et Herbar. 



