1 88 TORTULACE^I. 



cylindricj slightly curved, long; lid large, half as long as the 

 capsule ; peristome very long, tubular in the lower half, pink. 

 Dioicous. 



Hae. Thatched roofs, stony ground, walls, etc. Common. Fr. spring. 



A very fine species, often covering the thatch of roofs, and then reaching its 

 highest development ; when growing on the ground or on walls it is often shorter, of 

 a browner tint, with shorter, straighter leaves, in short with more the appearance of 

 T. intermedia ; but I have not observed, in these forms, any corresponding approach 

 to that species in leaf structure or in other distinguishing characters, and I am there- 

 fore inclined to allow T. intermedia full specific rank, though in the opinion of many 

 continental botanists it does not deserve more than a subordinate position. With the 

 following sub-species it is different ; the fruiting characters are the same as in 

 T. 7-uralis ; the areolation presents no points of difference, and, moreover, intermediate 

 forms may be observed. 



T. ruralis rarely grows on trees, and is not likely, for that and other reasons, to 

 be confounded with T. Icevipila ; T. princeps is synoicous, and has the leaves erecto- 

 patent, not recurved. 



* Tortula ruraliformis Dixon. {Barbula ruraliformis Besch.; 



T. ruralis var. arenicola Braithw., Br. M. Fl.) 



(Tab. XXVIII. G.). 



Differs from T. ruralis in the colour, golden brown or reddish, 

 very rarely green above, in the leaves somewhat narrowed above 

 and at apex acute with the lamina running out into a hyaline 

 dentate point becoming confluent with the excurrent nerve. 

 Perichastial bracts broader, plicate. 



Hab. Sandy sea-coasts, not common. 



The somewhat acuminate leaves, acute, with the lamina on each side of the nerve 

 hyaline at apex and forming a broad point similar to that of Rhacomitrium give this 

 plant a very distinct appearance, and form a character which can hardly be- considered 

 unimportant ; the degree of acuteness however varies somewhat, the lower leaves, too, 

 being sometimes quite broad and obtuse at apex, and intermediate forms are also 

 found ; the fruit, moreover, is in all respects that of T. ruraiis, and on the whole it 

 can hardly be conceded specific rank. It is usually a more robust plant, with longer 

 leaves. 



It is rarely found inland, but on some parts of our coast it is abundant, usually 

 being embedded up to the apex in the sand ; in West Cornwall it is in places so 

 abundant (while the typical form of T. ruralis is rare) that the late W. Curnow told 

 me he had always taken the present plant for typical T. ruraiis, and the roof-growing, 

 obtuse-leaved plant for a variety ! 



The fruit is much less common than is the case with T. ruralis. 



Barbula aciphylia B. & S. is an allied plant, probably also to be ranked under 

 T. ruralis, with the leaves similarly acute, but the nerve running out into a red, 

 hardly hyaline, rigid arista, which is almost entire. 



19. Tortula princeps De Not. (Barbula Mulleri B. & S., 

 Schp. Syn.) (Tab. XXVIII. H.). 

 Tall, robust, resembling T. ruralis. Stems forked, with 

 short nodose branches. Leaves in interrupted rosulate tufts 



