Floristik, Geographie, Systematik etc. 261 



Arnes, O., The orchids of Guam. (Philipp. Journ. Sei. C. Bot. 

 IX. p. 11 — 16. Feb. 1914.) 



Contains as new: Coelogyne guamensis, Liparis guamensis, En- 

 lophia Macgregorii, E. guamensis, Bulbophyllum guamense, Dendro- 

 bium guamense, Phreatia Thompsonii and Saccolobium. gua^nense. 



Trelease. 



Cannon, W. A., Botanical Features of the Algerian Sa- 

 hara. (Garn. Inst, of Washington. Publ, 178. 1913.) 



This report of 81 pages is illustrated by 36 plates of 84 photo- 

 graphs taken on the journe}- and an insert map of the country 

 and route. 



The author details the itinerary, the geographic characteristics 

 of Algeria and the climate of the country in the first 15 pages of 

 the report. The contents of the volume are arranged, as follows: 

 Some characteristics of the Vegetation of the Teil; the forests of 

 Algeria; the high plateaus (Boghari to Laghouat), the oasis, the 

 piain, the dunes near Laghouat; region of the Dayas; Ghardaia; 

 root habits in the Ghardaia region; leaf habits in the Ghardaia 

 region; Ghardaia to Tonggourt; Ghardaia to Ouargla (Vegeta- 

 tion); Ouargla to Tonggourt (Vegetation); the Biskra region (topo- 

 graphy, Vegetation) and a general summary with a comparison of 

 some of the general features of the Vegetation of southern Algeria 

 and of southern Arizona, The author concludes that the physical 

 environment of the plants of southern Algeria is, in a few brood 

 features, similar to that of the southwestern portion of the United 

 States. There are other features, however, particularly as regards 

 the amount and the distribution of the precipitation, in v^^hich the 

 two v^idely separated regions are very unlike, and a correlated 

 difference in the habit and composition of the two regions is apparent. 



Harshberger. 



' to^ 



Cannon, W. A., Some relations between salt-plants and 

 salt-spots. (Dudley Mem. Vol. Stanford Univ. N». 11. p. 123— 

 129. 1913.) 



The results of observations on a salt-spot at the edge of the 

 flood-plain of the Santa Cruz River, four miles northwest of the 

 city of Tucson Arizona, are given in this paper. Cannon finds 

 that the saltplants have a well-worked zonal distribution. The first 

 circumarea shows Atriplex canescens, the second A. polycarpa, 

 the inner A. Nuttalli and with it A. elegans and Suaeda suffrutes- 

 cens. There are no plants in the centre. The soil was studied as to 

 its physical chemic character and the electric resistance of the soil 

 and Solutions of the plants was determined. The author finds that 

 where the soil Solution is most dense and carries the most salts, it 

 is inhabited by A. Nuttalli, which contains the largest proportion of 

 sodium. The study indicates that the most intense halophytes ab- 

 sorb salts of large amounts without injury, and that it is due to this 

 that such species can survive where such salts constitute the leading 

 features of the substratum. Harshberger. 



Darling, C. A., Handbook ofthe wild and cultivated flo- 

 wering plants. Published by the author. (Columbia Univ. 

 New York City. VIII. 264 pp. $ 1.25.) 

 A pocket manual in duodecimo, consisting of primary keys 



