HEDWI'GIA. l6l 



Var. (3. leucophsea Schp. More robust, very hoary ; leaves 

 wider, the base of the hair-point occupying almost one-third of 

 the length of the leaf. 



Var. y. viridis Schp. Leaves imbricated when dry, bright 

 green, tip hardly hyaline. 



Var. 8. striata Wils. Leaves (especially the uppermost) 

 distinctly striate ; margin strongly recurved. 



Hab. On siliceous walls and rocks, common. The var. ,8 on more exposed 

 rocks. The var y in more shaded localities, rare. The var. S rare. Fr. spring. 



This species is somewhat variable, especially in the relative length and con- 

 spicuousness of the hyaline point ; the vars. viridis and leucophaa are little more than 

 extremes of variation in this respect, linked with one another by innumerable 

 intermediate forms. Another form described by Schimper as var. secuiida is also 

 found ; it is only a more than usually elongated slender form with smaller, less 

 crowded, more secund leaves than usual. 



Hcdwigia ciliata somewhat resembles Rhacomitrium heterostichum, and still 

 more perhaps Grimmia apocarpa, but the broader ovate leaves regularly imbricated, 

 at the base at least, when dry, are totally different upon closer examination. Forms 

 without hyaline points, which are however rare, might be taken for the next species, 

 but are nearly always of a decided green, less yellow ; it would always be safer, how- 

 ever to submit such forms to the microscope, when the strongly papillose leaves would 

 clearly refer them to the present species. 



2. Hedwigia imberbis Spruce. (Gymnostomum imberbe Sm.; 



Hedwigidium imberbe B. & S., Schp. Syn. et plur. auct.) 



(Tab. XXIV. J.). 



Resembling the last species in mode of growth, but with the 

 stems less forked, with lateral branches, sometimes flagelliform at 

 apex, dark brown below, yellowish brown at the summits of the 

 branches, not hoary ; leaves spreading, rarely falcato-secund, 

 closely imbricated when dry, resembling the last in shape, oval- 

 oblong, quickly narrowed to a short acute apiculus, not hair- 

 pointed, nerveless ; margin strongly revohde almost to summit, 

 slightly notched or irregular at apex. Basal cells resembling 

 the last, the upper smaller, narrower, usually irregularly 

 rectangular and elliptic, or sub-quadrate, with incrassate 

 sinuose walls, smooth or slightly papillose. Leaves of the 

 flagelliform shoots and perichaetial bracts with the apex some- 

 times discoloured. Capsule on a rather longer seta, slightly 

 exserted ; lid conical-rostellate, calyptra small, cucullate or sub- 

 cucullate. Autoicous. 



Hab. Siliceous rocks, rare. Fr. autumn. 



Usually easily distinguishable from the last by the absence of hyaline points to 

 the leaves, which are almost always brown or yellowish, more imbricated when dry, 

 with the margin more strongly recurved ; also by the smoother, smaller and narrower 

 areolation. 



