156 
J. R. Matthews. 
Again, R. hibernica, described by Templeton in Trans. Dublin 
Soc. III. 1803, from plants found in the North of Ireland, is now 
regarded by all rhodologists as a hybrid between R. pimpinellifolia 
and R. canina Linn. sp. agg., although this view was not generally 
accepted when first advanced by Christ in 1875. R. hibernica is a 
comparatively rare plant, being known from only a few vice-counties 
in the North of England and from a few in Scotland, besides its 
two stations in Ireland, and apparently only the glabrous variety has 
been found on the Continent. The typical plant has leaflets hairy 
at least on the nerves below which is sufficient evidence to show 
that the second parent is a dumetorum or a coriifolia form, probably 
the former if the sepals become reflexed, the latter if the sepals 
become erect. R.hibernica var .glabra Baker has glabrous leaflets, 
and possibly in this case the second parent is a form of R. canina or 
of R. glauca, both of which are without pubescence on the leaves. 
R. hibernica, like R. involuta, is almost universally sterile and the 
remarks made in the discussion of the latter apply equally to this 
hybrid. 
R. pimpinellifolia hybridises also with R. rubiginosa , but the 
hybrid is extremely rare. The British forms, the first of which 
was recognised as recently as 1896, have not received a binomial, 
but they are not markedly different from the French forms of the 
hybrid known as R. biturigensis Bor. The hybrid is most abundant 
on the coast of Haddington, where it grows in association with both 
parents. It is remarkably luxuriant, some of the bushes attaining 
a height of eight or nine feet. The plants are not so obviously 
sterile as the majority of R. involuta and R. hibernica forms, and two 
distinct types are recognisable in the shape of the fruit. In one 
the fruit is ovoid or oblong, recalling that of R. rubiginosa , in the 
other it is globose and therefore similar to that of R. pimpinellifolia. 
A hybrid of R. pimpinellifolia and R. mollis has been recorded 
from several vice-counties in Scotland, the first record being based 
on the determination of specimens from Sutherland by Crdpin. 
Similar plants have been discovered in Banffshire and in Perthshire 
and in all cases the evidence tends to point to R. mollis as the 
second parent. In addition the following hybrids, which do not 
involve R. pimpinellifolia, are recorded by Wolley-Dod (1911)— R . 
arvensis Huds. X stylosa Desv., R. suberecta Ley. x mollis 
Sm. and R. suberecta Ley x coriifolia Pr. In the absence 
of experiment it is impossible to confirm or contradict these 
determinations. The first two hybrids must be uncommonly 
