244 ORTHOTRICHACE^E. 



trees ; and U. maritima C. M. & K. , shorter, green, blackish below, with shorter 

 seta and shorter, thicker capsule, growing on rocks near the sea. They also point out 

 other characters in the leaves, all of which however I have found either erroneous or 

 belonging indiscriminately to both forms. Nor will the above distinctions drawn from 

 the vegetative characters hold good, for the short dark plant has been gathered on 

 trees, while the finest specimens of the yellow and brown form I have seen I gathered 

 on rocks at the Giant's Causeway. The fruiting characters may be more important, 

 but it is doubtful whether the capsules can be satisfactorily compared, since those of 

 " U. maritima " were young and full of spores, while those of " U. phyllantha" were 

 old and empty, a condition which implies a lengthening and narrowing of the fruit. 

 Mrs. Britton concludes that "if we maintain to/s and crispula as distinct species, 

 then these are," but I am convinced that no distinction can be drawn from the 

 vegetative characters of the two forms ; nor do I think that the slight difference in the 

 fruiting characters, even as described, is any greater than can often be found between 

 the different gradations even of the single form U. crispa var. intermedia. I do not 

 think therefore there is any ground for separating the maritime form from the 

 arboreal one. 



The abundant brown gemmse at the tips of the upper leaves are alone sufficient to 

 distinguish U. phyllantha from any other moss. It is almost a cosmopolitan species, 

 and curiously enough grows luxuriantly at the highest limit of vegetation on 

 Chimborazo, while it is often found closer, perhaps, to the sea level than any moss but 

 Grimmia maritima. 



7. Ulota HutchinsisB Hamm. (Orthotrichum Hutchinsise 



Sm. ; Weissia americana Lindb., Braithw. Br. M. Fl.) 



(Tab. XXXIV. J.). 



In flat tufts, very short, rigid, fragile, dark purplish brown 

 or blackish. Leaves when dry not curled, erect and appressed, 

 straight or very slightly twisted, short, wide and rather obtuse 

 at the apex, the base oval or oblong ; nerve strong ; basal cells 

 linear or vermicular, a few rows at margin short, sub-quadrate, 

 partly hyaline ; upper cells small, rounded, very incrassate. 

 Capsule oblong-pyriform, when dry hardly contracted at the 

 mouth (until old) ; peristome double ; calyptra hairy. Autoicous, 



Var. ft. rufescens E. G. Britton (Bulletin of Torrey Club, Vol. 

 21, p. 69). Looser, taller and more slender, green, not purplish 

 black; leaves laxer, longer, more tapering, green; cells less 

 incrassate and distinct, the basal rectangular, not linear nor 

 vermicular. Capsule less distinctly striate when dry. Growing 

 on trees. 



Hab. Siliceous rocks, not common. The var. fl on sycamores, Beddgelert 

 (Dixon 1888). Fr. summer. 



Quite distinct from the other species, except U. Drummondii, in the straight, 

 rigid, appressed leaves when the plant is dry; luxuriant specimens, however, and 

 occasionally the uppermost leaves in smaller plants show a slight tendency to twisting. 

 U. Drummondii differs in the leaf-form and areolation, in the colour and habitat, the 

 larger capsule with contracted mouth, and other points ; but the var. rufescens of the: 

 present plant is not at all unlike it in appearance. 



