156 Floristik, Geographie, Systematik etc. 



respective zones for these types. In the insular area of Corsica, 

 amongst the mountains a high humidity characterises the Arbutus 

 zone, and still higher there comes the Fagus-Ilex wood with a 

 somewhat similar ground- Vegetation, but the beech in Corsica 

 takes the place of oak in Ireland. W. G. Smith. 



Rayner, M. C, W. N. Jones and J. W. Tayleur. The Ecology 

 of Calhina vulgaris on the Wiltshire and Berkshire Downs. 

 (New Phytologist. X. p. 227—240. 2 figs. 1911.) 



Calluna associated with heath plants occurs locally on the Chalk 

 Downs of southern England, apparently correlated with the fact 

 that the chalk is overlaid by "clay-with-flints", which in the present 

 instance is a yellowish clay, a soil not generally favourable to Cal- 

 luna. Apparently it is an invader and selects the more fertile soils 

 of the area. The present paper gives preliminary observations on 

 an investigation carried out mainly on an area (fig. 1) where a 

 series of holes was made, some on the Calluna area, others beyond 

 it. Details for each hole are given, as to thickness of soil-layers 

 (fig. 2) and other soil-conditions; also the root-system of Calluna 

 which in some cases extends downwards to the chalk rubble. The 

 soil-analyses show that the Calluna occurs on soils comparatively 

 rieh in mineral constituents (phosphoric aeid and nitrogen), but 

 poor in lime. The soils contain a relatively high proportion of 

 magnesia, and it is suggested that this is a significant edaphic 

 factor. The soil is neutral. No other edaphic factor has as yet been 

 found to aecount for the presence of Calluna. W. G. Smith. 



Scarth, G. W., Scheuchseria palustris, L. Its oecurrence as a 

 British plant, with a fresh record. (Notes R. Bot. Garden, 

 Edinburgh. XXII. p. 57—60. 1 plate. 1911.) 



The geographical ränge of the species is given with notes on 

 its British distribution, 4 stations on or near the piain of York, 

 4 in Shropshire. In the one Scottish locality, the plant seems to 

 have disappeared, but the author found it (July 1910) on Rannoch 

 Moor in western Pertshire and Argyll, an extensive tract of 

 moorland. The species was fairly abundant in a very wet peaty 

 marsh associated with Carex limosa and other plants of marshy and 

 peaty habitats. The plate is a photograph of the entire plant. 



W. G. Smith. 



Schlechter, R., Die Gattung Bletilla Rehb. f. (Rep. Spec. nov. 

 X. 15/17. p. 245-256. 1911.) 



Die Untersuchung des Originals von Arethusa sinensis Rolfe 

 führt Verf. zu der Ueberzeugung, dass diese Art zu der Gattung 

 Bletilla Rchb. f. gehört und sich hier eng an B. striata (Thbg.) 

 Rchb. f. anlehnt. Die weitere Untersuchung der Gattung Bletilla 

 Rchb. f. veranlasste Verf. dieselbe aus der ihr von Pfitzer zuge- 

 wiesenen Stellung neben Thunia Rchb. f. zu entfernen. Verf. spricht 

 dieselbe als echte Polychondree an, welche in die Vervvandschaft 

 der Gastrodiinae gehört und hier am besten als eigene Gruppe zu 

 führen ist. Auch die von A. Gray beschriebene Arethusa japonica 

 ist zu Bletilla Rchb. f. zu ziehen, sodass derart sowohl das Areal 

 der Verbreitung der Gattung Arethusa Gronov. auf Nordamerika 



