388 



JOURNAL OF THE ROYAL HORTlClULTllRAL SOCIETY. 



ai'6 usually now drained and pastured). Blue grass fornis a zone froiu 

 the forest to the former level of standing water. Then follows 

 Ambrosia, Ewpatoriiim, Bidens, Polygonum acre, Verbena (selected 

 through pasturing?), and in the wettest places Iris, Mimulus, and 

 Scirpus. 



The succession of Oak-Hickory, Bur Oak, and Eed Oak is usual in 

 Central Illinois, and is caused by accumulation of humus and increasing 

 shade. 



The forest is considered to have reached the locality by immigration 

 from the moraine to the north-east, which was once forest-clad. The 

 forest has been removed by prairie fires, except where protected, as at 

 Bur Oak Grove, by depressions or sloughs in which standing water used 

 to accumulate. — G. F. S. E. 



Prickly Pears. By J. H. Maiden {Agr. Gaz. N.S.W. vol. xxiii. 

 pt. iii., pp. 208-290; 2 plates). — Opuntia nigricans, frequently called 

 0. Tuna, is legislated against in New South Wales. It is 6 to 10 feet 

 high with spines 2^ inches long. The flowers vary in colour from 

 yellow to orange and pink. The pyriform fruit is carmine in colour. 



S. E. W. 



Provence, Forests of. By A. G. Tansley (Gard. Chron. pp. 89, 

 112, 131; Aug. 3, 10, 17, 1912; 7 figs.).— Treats of (1) The Mediter- 

 ranean coniferous forests; (2) the deciduous woods of the " Montane " 

 region; (3) montane and sub-alpine coniferous forests. — E. A. B. 



Pseuderanthemum lilacinum {Bot. Mag. t. 8446).— Malay 

 Peninsula. Family A canthaceae. Shrub, 3 feet' high. Leaves lanceo- 

 late, 4^-10 inches; inflorescence paniculate ; corolla tube slender, 11- 

 inch long ; lobes 1^ inch across ; pale lilac v/ith red specks on the 

 mid-lobe of the lower three. — G. H. 



PuCCinia g"raminiS. By Frederick J. Pritchard {Bot. Gaz. 

 pp. 169-192, Sept. 1911; 1 plate). — This is a preliminary report on 

 the yearly origin and dissemination of Puccinia graminis. The author 

 gives a brief historical resume, and describes a number of inoculation 

 and other experiments. He considers that there are three distinct 

 biologic forms — that of wheat, that of barley, and a third affecting 

 oats, Avena fatua, rye, Hordeum jubatum, and two species of Agro- 

 pyrum. The barberry was as easily infected by the Puccinia from 

 wheat as from Agropyrum, Hordeum, and Elynius. Aecidiospores 

 were not carried by wind for more than 100 yards, and few seemed 

 to travel 80 yards. 



Puccinia does not seem to spread to wheat by aid of the grasses. 

 Near the barberries, Uredo appeared on the winter wheat quite as 

 soon as upon the grasses near barberry bushes, and away from these 

 bushes,' with one exception, it was generally present on spring wheat 

 before it appeared in grass. Uredospores failed to survive the winter 

 at Fargo, Dakota. 



