188 THE JOUKNAL OF BOTANY 



divergent from the ordinary as almost to entitle this species to be 

 placed in a monotypic section of the genus. Owing to the rarity of 

 S. hercynicum we have no knowledge of its variability, and no 

 conclusion can be reached as to whether the thickness of the cell- 

 walls is constant. As variability seems to be the most universal 

 attribute of Sphagnum characters, one may legitimately infer that, if 

 S. hercynicum were better known from a wide range of habitats, it 

 would be found occasionally to show thinner-walled cells, such as are 

 seen in Mr. Binstead's plant and in the vast majority of the 

 Sphagna. The evidence seems conclusive that the Cefn specimens are 

 certainly nearer S. hercynicum than S. inundation. The fact that 

 the latter is a common British plant, and the former hitherto re- 

 stricted to the Harz district, would have more weight were not the 

 distribution of many species of Sphagnum so eccentric. Some, like a 

 few common lichens and mosses, are of world-wide range ; others 

 restricted to very limited areas, and a few occur sporadically in 

 localities widely separated by oceans and continents. At present, 

 therefore, it seems desirable to subordinate Mr. Binstead's plant to 

 S. hercynicum as a variety, rather than to S. inundatum, though it 

 may ultimately prove to be a new endemic species. The following 

 diagnosis indicates the chief features separating it from typical 

 S. hercynicum Warnst. : — 



Var. nov. Binsteadii, mihi. Planta robustiora, cjuasi 10 cm. 

 alta, viridis, sursum sublutea. Ramorum fasciculi plus remoti. 

 Faulia caulina paulo majora 1/5 mm. longa, 07 mm. lata; folia 

 ramulina T4-T8 mm. longa 0"7-0 - 8 mm. lata. Hyalodermis caulis 

 strato uno, cellulse sectione transversali elliptical, cum parietes non 

 valde incrassatae. 



Cefn Hill (alt. 1500 ped.), Herefordshire, 27 April 1921. Leg. 

 C. H. Binstead. 



The stem-leaves of our S. aquatile W. occasionally have a few 

 pores in mid-cell on the outer side of the leaf, but its other characters 

 will prevent it being mistaken for S. hercynicum. 



In S. armoricum Warnst., a plant of Brittany, the stem-leaves 

 have a similar pore-structure to those of S. hercynicum, but the 

 branch-leaves differ in being nmltiporose on both sides, without the 

 supplementary row of median pores, and the cells of the hyalodermis 

 are of the ordinary roundish outline. 



NOTES ON BRIDELIA. 

 By H. H. Haines, CLE., F.L.S. 



I. BkIDELIA MONTANA Willd. 



Bridelia montana as described by J. D. Hooker in the Flora of 

 British India (v. p. 2(39) is attributed to Willdenow (Sp. PI. iv. 

 p. 978; 1805) ; the references arranged chronologically are : — Clui/tia 

 montana Roxb. Cor. PI. ii. 38, t. 171 (1798); Bridelia montana 

 Willd. he. j Wall. Cat. 7879 in part (1828); Roxb. PI. Ind. (ed. 



