40 POLYTRICHACE/E. 



Var. p. longisetum Lindb. {Pogonatum nanum var. longi- 

 K^wHampe). Leaves longer, narrower; seta long, i-i£ inches; 

 capsule oval-oblong. 



Hab. Sandy ground on banks and heaths. Frequent. The var. B rare. Fr. 

 usually winter and spring, but variable. 



There is considerable variation in the length and the serrature of the leaves, 

 length of seta, and form of capsule ; but the present species is generally sufficiently 

 distinct from the next by the obtusely serrate leaves, and in doubtful cases the cylin- 

 drical columella, without wings, will clearly distinguish it. Fortunately for the 

 student, the species of this genus, although dioicous, are usually fertile, and the fruit 

 is of great aid in the determination of the species. I have always found the capsule 

 perfectly smooth, or at the most extremely faintly mamillate at the base, while P. 

 aloides, according to my observations, has the whole surface of the fruit distinctly 

 papillose. 



2. Polytrichum aloides Hedw. (Pogonatum aloides P. Beauv., 



Schp. Syn.) (Tab. X. C). 



Usually more elongated in all its parts. than the last species; 

 stem taller, f-f inches high, sometimes forked. Leaves longer, 

 linear-lanceolate, obtuse or acute, densely and sharply serrate 

 from the base of the limb, several cells usually entering into the 

 composition of each tooth. Lamella? more numerous, 40-60, 

 lower, in section of 3-5 cells. Calyptra slightly narrower, cover- 

 ing the entire capsule, which is oblong-cylindrical, erect or 

 slightly inclined ; constricted below the mouth and urceolate 

 after the fall of the lid, distinctly papillose over the whole surface ; 

 greenish brown or brown. Columella four-winged. Peristome 

 teeth shorter. 



Var. p. Dicksoni Wallm. (Polytrichum Dicksoni Turner, 

 Pogonatum aloides var. defluens Brid., Schp. Syn.). Dwarf ; 

 seta very short, capsule obovate, finally urceolate or turbinate ; 

 hairs of calyptra sometimes confluent below the capsule. 



Hab. Dry banks, disused quarries, etc. A much more frequent species than 

 the last. The var. B not common. Fr. as in P. nanum. 



Much like the last species and similarly variable, but quite distinct as noted under 

 that plant. These two species are often separated from the following under the title 

 Aloidella, derived, like the specific name of the present species, from the solid, 

 toothed, aloe-like leaves. The two following species are taller, more branched, with 

 longer, more pointed leaves. 



3. Polytrichum urnigerum L. {Pogonatum umigerum P. 



Beauv., Schp. Syn.) (Tab. X. D.). 



Stems in lax patches, rigid, erect, 1-3 inches high, innovating 

 laterally, sometimes twice or thrice forked or with several close, 



