MISCELLANEA BRYOLOGICA 325 



least have led to their segregation as D. affine and D. laxifolium), 

 and there can be no doubt I think of their belonging to one very 

 widely distributed species. Farther, the South African plants of 

 Ecklon and Gueinzius, on which C. Miiller has based his Lepto- 

 trichum capense, are undoubtedly the same thing. 



I have also examined original specimens of D. plicatum 

 (Mont.), (Leptotrichum plicatum CM.) from South India, and 

 these are without question the same. C. Miiller separates this 

 species in the Synopsis from those above referred to as having the 

 leaves curled (" folia crispata "), as against " folia secunda " ; but 

 the value of this distinction is minimized by his description of the 

 leaves of L. capense as " crispa," while L. affine is described 

 (p. 452, sub L. Boryanum) as " foliis crispatis." He also 

 describes the Indian species as having the capsule " cylindrica 

 erecta " ; but this is by no means borne out by the specimens, 

 where the capsule when well developed shows the slightly 

 curved, asymmetrical form characteristic of the whole of this 

 group. 



I have not seen the Isle of Bourbon plant, but from C. Miiller' s 

 description in the Synopsis, and from the recorded distribution 

 (Eeunion, Madagascar), I am driven to conclude that the Isle of 

 Bourbon L. Boryanum is absolutely identical with the South African 

 species. Furthermore, the Javan plant referred to L. Boryanum 

 by C. Miiller and by the authors of the Bry. Javanica must also 

 be placed here. Fleischer, it is true, now retains the Javan plant 

 distinct as Ditrichum difficile (Duby), but he gives no reason for 

 so doing beyond saying that he is doubtful if it is identical with 

 the Bourbon species, not having seen specimens. In the descrip- 

 tions and figures of the Javan plant I find nothing to suggest a 

 difference from Dicranum flexifolium Hook, except on one point, 

 that both the Bry. Jav., tab 76, and Fleischer depict the leaf base as 

 having the nerve quite narrow (about one-fifth the width of leaf) and 

 well defined," whereas in D. flexifolium it is much wider and ill- 

 defined at margin. However, examination of Javan plants does not 

 bear out the figures. Both Fleischer's specimens (M. Fr. Arch. 

 Ind. No. 28, as D. Boryanum) and specimens in the British 

 Museum, leg. Lacoste, show the nerve very wide and ill-defined, 

 often fully one-third the width of the leaf-base, and, in the older 

 leaves, bright orange in colour. The sheathing leaf-base is not 

 very easy to flatten out, and when conduplicate it gives the 

 impression that the nerve is quite narrow and well-defined, and 

 this is possibly the cause of the error. The appearance is due, I 

 believe, to the strongly thickened dorsal band of stereid cells in 

 the middle of the nerve, which is prominent, and, together with 

 the position of the deuter cells, gives the appearance by trans- 

 mitted light of being itself the complete nerve, instead of being 

 only the central portion. On flattening out a leaf-base the nerve 

 is distinctly seen to be as described above. 



D. Boryanum is, it is true, separated by Brotherus from 



* The authors of the Bry. Jav., however, describe it as costa lata, applanata. 



