Floristik, Geographie, Systematik etc. 393 



bank of the Severn Estuary. (Proe. Bristol Nat. Soc. III. 1. 

 p. 9— '25. 2 figs. 1911.) 



The observations were made on a limited area of mud outside 

 the seaward dune and submerged at the highest tides. Here the 

 land-margin is gradually sinking in consequence of tidal scour, the 

 outer mud is carried away causing the landward-lying mud with 

 any Vegetation on it to subside, so that from the land to the sea 

 the surface drops in a series of Steps varying in depth from a few 

 cm. to 2 metres. On these Steps pelophilous plants form well-marked 

 zones with the general sequence: a) land ward sand-dune; b) reclai- 

 med pasture used for grazing; c) zone of Festuca rubra, Juncus 

 Gerardi, etc.; d) zone of Sclerochloa maritima and Aster tripolium 

 with Plant ago maritima, Triglochin, Glaux, Sueda, etc.; e) zone of 

 Salicornia ; f) mud bank of water. The relations ol this series of 

 zones to salt-content and drainage were investigated, and tables 

 show total chlorine present, moisture and previous rainfall. The 

 results are plotted as curves against the zones of Vegetation and 

 lead to the following conclusions: l) The halophytic character of 

 the Vegetation is aecounted for by the high chlorine content after 

 tidal submergence; 2) the greater number of species present in the 

 higher halophytic plant association can be attributed to better drai- 

 nage which with periods of good rainfall and low tides leads to the 

 oecurrence of periods of very low salt content; 3) the minimum 

 salt-content in the lower zones {Salicornia =.21 p.c.), is uniformly 

 higher than the minimum content for the higher zones {Sclerochloa 

 = , 09 p.c., Festuca =.03 p.c.); 4) the reclaimed pastures owe their 

 existence to a uniformly low saline content due to infrequent tidal 

 immersion owing to higher level, and to improved surface drainage 

 from aecumulation of humus. W. G. Smith. 



Rendle, A. B. and otheFs. A contribution to our know- 

 ledge of the Flora of Gazaland: being an aecount of 

 collections made by C. J. M. Swynnerton. (Journ. Linn. 

 Soc. XI. p. 1—245. 9 pl. 1911.) 



The paper is based upon collections made by Mr. Swynnerton 

 in the high country, which forms the boundary between Eastern 

 Rhodesia and Portugese East Africa, a district from which few 

 botanical speeimens had previously been gathered. An aecount of 

 the expedition and a description of the region and its Vegetation 

 is supplied by the collector. 



The collection has proved remarkably rieh in novelties, 184 

 Phanerogams being described. Numerous notes of economic interest 

 or respecting the morphology of the better known species of which 

 there are several new varieties are also given. A few of the most in- 

 teresting new species noted by the authors are worthy of mention. 

 Such are an Anemone (A. peneensis) which forms in some respects 

 a connecting link between the genera Anemone and ■ Knowltonia , 

 two fine species of Gardenia (67. Norae and G. posoquerioides and a 

 "magnificent Leonotis" [L. spectabilis). 



The flora of Gazaland shows a strong affinity with that of 

 South Africa, several genera not previously known to oeeur north 

 of Natal and the Transvaal being recorded, some by new species. 

 Other affinities noted, besides that of the adjacent Zambesi Basin 

 westwards to Angola, are with the highlands and mountains of 



