THUIDIUM PHILIBERTI LLMPE., A NEW BRITISH MOSS. 17 



conic-rostrate, curved; spores •012--016 mm., almost smooth, 

 maturing in October. (Plate 260.) 



In wet swampy places on the ground or the base of small trees. 

 New Jersey (Best) ; Pennsylvania (Porter). 



Dr. Best remarks that it is probably an involute form of T. deJi- 

 catuluiii Mitt. I think, however, it may be doubted whether its 

 relationship to T. recognitum Lindb. is not at least as close. 



It may be as well to point out that the re -naming of the species 

 by Limpricht was necessitated by the fact that the name T. inter- 

 meduim was already preoccupied by a species of Mitten's. 



Like most of its aUies, ThnUium Philiherti is usually found 

 barren; it will therefore be helpful to indicate the characters by 

 which, even without fruit, it may be recognised from T. ddicatubim 

 and T. recof/nituw, the only two British species with which it could 

 be confused. (The simply acute apical cell of the branch-leaves of 

 2'. tamariscinum at once separates that species.) In the branching 

 it is somewhat intermediate between the two, being frequently tri- 

 pinnate, though less regularly and distinctly so than in T. delica- 

 tidum. It also grows in more or less damp situations, whereas 

 T. recognitum is usually found on dry calcareous soil. 



But the most characteristic feature, and the one that to my 

 thinking gives it one of its best claims to distinction, is the long- 

 drawn-out, filiform point of the stem-leaves, forming a fine hyaline 

 jointed hair composed of a single row of linear cells, and of some 

 considerable length. In the older leaves it is often broken off, but 

 otherwise it is probably always present, and is especially noticeable 

 in the tuft of leaves at the apex of a growing steui or new shoot. 

 In this character the plant shows an approach to some exotic 

 species, such as T. ci/tnhifoliutn Dozy & Molk. 



The stem-leaves in T. rccognituw, more rarely in T. delicatuhim, 

 are occasionally tipped with a short point of a similar nature ; but 

 it rarely consists of even two or three cells in length, and is never 

 prolonged into a long flexuose hair-point, as in T. FhUiherti. T. 

 delicatulum difi'ers from both the other species in the stem-leaves 

 more erect and less spreading, indeed when dry appressed to the 

 stem with the point scarcely showing ; in T. recognitum and T. 

 I'hUiherti they are, on the other hand, widely spreading when 

 moist, and even when dry the long acumen is frequently recurved, 

 and always forms a much more distinct feature than in T. delicatulum, 

 which in this respect resembles T. t<niiariscinum. The long spreading 

 acumen is indeed quite enough to separate the two former species 

 from these two, with the lens alone ; the difference being most 

 marked when the plant is dry. 



r. Philiherti has only been figured (and there not quite satis- 

 factorily) by Dr. Best in the publication referred to. It has been 

 found in several localities in France and Switzerland, as well as in 

 the localities in the U.S.A. mentioned above, where it was inde- 

 pendently distinguished by Dr. Best. I have not heard of its 

 occurrence elsewhere, but it is not unlikely that it will be found 

 more or less widely distributed now that attention has been called 

 to its distinguishing characters. 



J0URN.VL OF Botany. — Vol. 35. [Jan. 1897.] c 



