BARBULA. • 201 



cells rather small, narrow, pellucid, yellowish, the upper small, 

 sub-quadrate, obscure, thin-walled, or incrassate, papillose. 

 Perichaetial bracts longer, sometimes much elongated, narrower, 

 sub-sheathing, but not convolute. Seta variable in length, 

 brownish red or purple, paler above ; capsule cylindric or 

 narrowly oblong, lid rostellate or rostrate, slightly curved, 

 variable in length. Annulus none. Peristome teeth long, very 

 slender, forming two complete turns of a spiral, narrowly 

 twisted at base, more loosely at apex, from a very short basal 

 membrane. Dioicous. 



Var. /3. cuspidata (Barbula cuspidata Schultz). More 

 slender ; leaves and perichaetial bracts narrower, with longer 

 cuspidate points, straighter ; seta slender, often flexuose. 



Hae. Banks, walls, and bare ground ; very common. The var. j8 frequent. 

 Fr. winter or spring, but variable. 



One of the commonest species of the genus, and extremely variable. Many 

 varieties have been described, but the characters on which they are founded are very 

 slight and unimportant. Almost every variety of leaf form and direction may be 

 found, from shortly and broadly oblong and very obtuse to narrowly linear or 

 elongate-lanceolate, and from straight and erecto-patent to squarrose-recurved. The 

 apex is sometimes, but rarely, narrowed so as to appear at first sight acute, especially 

 when folded laterally, but when flattened out it will be found to be invariably more or 

 less obtuse, the lamina often reaching slightly higher on one side of the nerve than the 

 other. The spirally twisted leaves with pale shining nerve in the dry state are very 

 characteristic, and the obtuse mucronate apex gives the leaf a distinct appearance by 

 which the plant is easily known in the field ; it is a taller plant of firmer texture than 

 any of the three preceding species, and could hardly, except in very short and delicate 

 forms, be mistaken for any of them ; and the margin regularly recurved, and nerve 

 excurrent in a distinct mucro, are sufficient points of difference in doubtful cases. 

 Young or starved forms may be confused with B convoluta, but the margin in that 

 plant is only slightly recurved, and the nerve rarely excurrent, the perichaetial bracts 

 quite different. 



41. LEPTODONTIUM Hampe. 



Leaves spreading or squarrose-recurved, rather wide, mostly 

 flexuose, with serrulate or notched margins. Capsule narrow, 

 cylindrical ; peristome of 32 filiform smooth teeth, straight, erect, 

 more or less unequal and here and there united in pairs. 

 Dioicous. 



The three British species of this small genus are readily 

 known by the peculiar habit and the form and structure of the 

 leaves, and with the few exotic and continental species appear to 

 form a well-defined group, hardly approached by any of the other 

 species of the Order except Pleurochsete squarrosa. 



