1922] CURRENT LITERATURE 159 
type of vegetation. In a recent article Sampson has made an excellent 
contribution to our knowledge of these rapidly disappearing grasslands. He 
found, in various parts of the state, remnants of the original prairie grasslands 
varying in size from strips along roadways and railways to tracts of hundreds 
or even thousands of acres in extent. Some of the largest areas were on the 
floodplain of the Mississippi River and occur even within the city limits of 
Chicago. The principal virgin areas were visited during the summers of 
1915-18 and carefully studied. 
The most notable contribution appears in a very complete explanation 
of the dynamics of these grasslands. Two main lines of succession are recog- 
nized, the hydrarch and xerarch, with a common climax association type in 
which Andropogon furcatus is dominant. The hydrarch succession commonly 
begins with an association dominated by Scirpus fluviatilis, succeeded by others 
in which Spartina Michauxiana or Calamagrostis canadensis is abundant. In 
the subclimax Panicum virgatum or Agrostis alba may be most conspicuous. 
Variations in the intermediate stages occur and are illustrated by examples. 
Owing to the agricultural value of the upland prairie areas the xerarch 
succession is not so easily solved, although there is abundant evidence of the 
nature of the climax association. Mixtures of herbaceous species with few 
grasses seem to be the probable pioneer forms, with a mixed aggregation of 
grasses or a is aeabe td pure stand of Andropogon scoparius as the inter- 
mediate stage. 
he present antes of Poa, appearing both as the dominance of P..pra- 
tensis in the climax association and of P. sinatra in the subclimax of the 
xerarch succession, is shown to be due to man’s influence in cutting and grazing. 
The retrogressions due to grazing, as well as the various types of succession, 
are made clear by numerous diagrams, by floristic analyses of the various 
associations, and by an annotated list of the principal species 
very commendable feature of the report is a mas teclaions summa 
which the main results of the study, including the principal successions, are 
stated in terms intelligible to the ordinary citizen acquainted with the prairies 
but without botanical training. A series of excellent plates also add to the 
interest and value of the report—G. D. FULLER. 
axonomic notes.—The collection of plants made by Compron in New 
balsdeaie and the Isle of Pines in 1914 is being published by various taxono- 
mists, the first part containing the Angiosperms by RENDLE, BAKER, and 
Moore." It includes 830 species, 230 of which are new. The ten new genera 
*s Sampson, H. C., An ecological survey of the prairie vegetation of Illinois. 
voles Dept. “Regie, and. Educ. Div. Nat. Hist. Surv. Bull. 13:523-577. pls. 48-77. 
gS. 9. 19 
on uk account of the plants collected in New Caledonia and the Isle of 
Pines by Profs sor R.H.Compronin1io14. PartI. Flowering plants (Angiosperms), 
by Renp AB. se Jour. Linn. Soc. 45:245- 
417. pls. 1 rear, 
