R. Babingtonii occurs in the Thames district near Seer Green, and the var. phyllothyrsus has been found by Mr. Britton near Beamond End. R. Lejeunei var. ericetorum occurs at Naphill and a closely allied form at Heath in the Ouzel district. The Sub-Bellardiani are represented by R. fuscus var. nutans, which Mr. Benbow records from near Farnham Common. R. scaber is found at Alderbourne, etc. R.foliosus occurs at Dropmore and Brickhill. The Kæhleriani include 'R. rosaceus, which as an aggregate species is widely distributed ; var. Hystrix occurs at Brickhill, the sub-species infecundus at Shalbourn in the Ouse district, and is not uncommon in the heathy parts of the Thames and Colne districts.
Sub-sp. Purcbasianus is the name suggested for a bramble I gathered at the Chequers in the Thame district, but in England it is a very local form. Sub-sp. R. adornatus was found by the Rev. E. F. Linton at Great Horwood in the Ouse district. R. fuscoater is very local at Elles- borough in the Thame and at Naphill in the Thames districts. R. Kæhleri as the var. cognatus occurs at Dropmore. R. dasyphyllus is the commonest woodland bramble on dry soils, occurring in all the districts ; it is the R.pallidus of Babington and many English writers, but not of Weihe and Nees. R. Marshalli grows about Black Park in both the Thames and Colne districts. Of the Bellardiani Mr. Benbow records R. viridis from Black Park. R. Bellardi occurs at Burnham. R. serpens has been found by Mr. Britton at Penn Street, and at Black Park by Mr. Benbow. R. birtus as the var. flaccidfolius has been already men- tioned. Of the Cæsii we have R. diversifolius rather frequently, especially in clayey soils, with a thin stratum of gravel, and it is found in all the districts. The Rev. W. Moyle Rogers finds the var. ferox near Brickhill. R. corylifolius is the commonest bramble on clay soils, and both the var. sublustris and cyclophyllus are found. R. Balfourianus is recorded for Brickhill and Alderbourne. R. cæsius, the dewberry, is very common in clay soils and in ditches and wet woods, and occurs in all the districts. Rubus carpinifolius and R. Salteri have also been found near Brickhill, and R. infestus near Chesham. Many hybrids of the various species occur. Large as is the number of species in the foregoing list it is by no means exhaustive ; a considerable amount of work still remains to be done, and several additional species will certainly be discovered.
THE ROSES (Rosa)
This group is not nearly so well represented as the brambles. The burnet rose (Rosa spinosissima) is not recorded, and therefore the involuta group, which consists chiefly of hybrids of spinosissima with R. villosa and R. mollissima, Willd. (R. tomentosa, Sm.), are also unrepresented, and R. bibernica, a hybrid of the burnet with the dog rose, for the same reason is absent. The sweetbriar R. rubiginosa is sparingly distributed over the county, but is more frequent on the chalk where, too, R. micrantha is also more common. R. sepium will almost certainly be found on the chalk escarpment, and I have apparently a form of it from near Marsh
59
