76 ECOLOGY, PLANT GEOGRAPHY [BoT. Absts., Vol. X, 



town, Colorado, in Clear Creek Canon at an altitude of 8500 feet. Four habitats are con- 

 sidered: sand, sand-gravel slopes, rock wash, and rock ridges. Three associations occur on 

 sand: (1) shrub association, (2) wheat-grass association, and (3) short-grass association. The 

 principal shrubs in the 1st of these associations are Symphoricarpos vaccinoides, Rhus 

 trilohata, Rihes inebrians, and Chrysothamnus linifolius. The shrub communities are con- 

 sidered as intermediate between grassland and coniferous forest, and it is pointed out that 

 well compacted soil tends to forests on steeper slopes, and to grasslands on more level areas. 

 A list of 64 species found on the sandy area is given. — Charles A. Shull. 



473. Ramalet, Francis. Vegetation of undrained depressions on the Sacramento plains. 

 Bot. Gaz. 68: 380-387. Fig. 1919. — The numerous depressions of the Sacramento plains 

 have a very fine-graded soil, where water stands during the period of winter rain and even into 

 early spring. The vegetation is very different from that of the usual grassland of the region, 

 being composed of very few species, with practically no introduced weeds. The depressions 

 usually show a central area and a marginal zone, the former characterized by a dense growth 

 of Allocarya or Baeria, and the latter by Floerkea Douglasii and Deschampsia danthonioides . 

 Subordinate species of both areas are noted and the seasonal changes indicated. A systematic 

 list is given of 29 species, 10 of which are marked as characteristic, 8 as frequent, and 11 as 

 merely occasional. — Francis Ramaley. 



474. Russell, W. Esquisse sur la vegetation d'un coin du Gevaudan granitique. [Sketch 

 of the vegetation of a corner of the granitic Gevaudan.] Rev. Gen. Bot. 32: 226-229, 256-269. 

 1 fig. 1920. — A brief description is given of the physiography and vegetation of the high un- 

 dulating plateau between the mountains of Aubrac and the Margeride. The vegetation is 

 divided into 4 physiognomic groups inhabiting respectively the prairies, woods, waste places, 

 and cultivated lands; lists of species constituting each group are given. The prairies are 

 particularly rich in montane species. — L. W. Sharp. 



475. Shreve, Forrest. A comparison of the vegetational features of two desert mountain 

 ranges. Plant World 22 : 291-307. 7 fig. 1919. — A description of the physiographic features 

 of the Pinaleno mountains is presented, and a comparison of the general vegetational and 

 floristic features of the Pinaleno range and the Santa Catalinas. The main differences noted 

 are due to the higher altitude, and the more sharply cut and better watered canons of the 

 Pinalenos. The higher altitude leads to more extensive development of a type of forest spar- 

 ingly represented at the highest altitudes of the Santa Catalinas; and the well watered canons 

 lead to a more conspicuous interdigitation of lowland and mountain vegetation on the slopes. 

 Comparative rainfall records for the two ranges are given for 1917, and lists of species found in 

 the Pinaleno mountains that are absent from the Santa Catalinas. Certain species found in 

 both ranges raise the question as to the means of dispersal of species from range to range across 

 the arid lowlands between them. The floristic differences indicate a secular movement of 

 species from the larger and higher ranges to the lower and more isolated ones, with rapid 

 impoverishment of the flora as the latter are approached. — Charles A. Shull. 



FLORISTICS 



476. Anonymous. The botanical survey of the Union of South Africa. Kew Bull. 1919: 

 399^03. 1919. 



477. Bailey, John W. Adventures in mossland : — Polytrichadelphus Lyallii Mitt. Bryol- 

 ogist 23 : 49-50. 1920. — This is a popular account of the collection of a rare moss upon Mt. 

 Rainier, with some notes upon its surroundings. — E. B. Chamberlain. 



478. Barnola, Joaquin Maria de. Notas fitostfiticas sobre la vegetaci6n bril6gica de 

 las cercanias del Lago de Bafiolas. [Ecologic notes upon the bryophytes of the neighborhood of 

 Lake Bafiolas.] Broteria Ser. Bot. 18: 64-73. 1920. — Lake Banolas is near the town of the 

 same name in northeast Spain. It apparently occupies a much smaller basin than formerly, 



