the Forth Naturalist Historian - Forth Naturalist and Historian ...

Series RADULAE
R. radula Weihe: As an aggregate species, Rogers considered this to be
locally abundant, with four forms including the type, which he did not see in
the Trossachs area. However, in 1998 typical radula was found by the Lake of
Menteith and Loch Earn. He also encountered “a good deal of radula, some of
which was nearly or quite typical, while other bushes were less so” (1897b) at
Stirling, and the typical form at Crieff. The true species is abundant in east and
south Scotland and scattered throughout the rest of Scotland.
R. radula Weihe var. echinatoides Rogers = R. echinatoides (Rogers) Dallman:
“Locally the most abundant form”; it is at its northern limit away from the NE
coast and does not occur in the Loch Earn area but can still be found at
Callander, Loch Tay, Lake of Menteith, and at Gargunnock. The next species,
R. scoticus, is equally as frequent.
R. radula Weihe var. anglicans Rogers = R. scoticus (Rogers & Ley) Edees.
Rogers comments “not seen growing by me”; however, on his second day he
collected on Black Hill just south of Callander what he believed to be “a weak
form” of what is now called R. dasyphyllus. Later, he redetermined it as
“anglicans or ericetorum … var. scoticus Rogers & Ley”. In turn this was upgraded
to a full species by Edees in 1974. It seems odd that Rogers did not come across
more of this bramble, as it is common in and around Callander; elsewhere it
occurs southwards down most of the west coast.
R. anglosaxonicus Gelert var. raduloides Rogers = R. raduloides (Rogers)
Sudre: The sole record is at Gargunnock near Stirling, from where Rogers
mentions “a very handsome form … [that] departs from the type considerably
in the direction of my raduloides var.” (1897b). It has not yet been refound there
but it does occur in Stirling in several places. This is predominantly a western
and south-western species, penetrating the Clyde/Forth valley eastwards.
[P. echinatus Lindley: “I have, I think, seen dried specimens from Stirling
Castle Hill” (1897b) (author’s emphasis) but this appears to be an error – it
seems unlikely Rogers would have missed the plant on his visit. This species
has not been reliably recorded north of North Yorkshire.]
Series KOEHLERIANI = HYSTRICES
Brambles of the Trossachs and Stirling 73
[Rogers detected what he considered to be “a weak form” of R. Koehleri
Weihe & Nees, var. pallidus Bab. = R. dasyphyllus in two stations. One has
proved to be R. scoticus (q.v.) and it is likely that the other, from near Lake of
Mentieth, will be the same. R. dasyphyllus is common throughout south
Scotland but thins out rapidly towards the Forth/Clyde line; it may well occur
in the Trossachs but in very limited quantity. The other member of this group
Rogers termed “my infecundus var. of R. rosaceus Weihe & Nees”, which was
possibly a form of R. furvicolor, found at Balloch at the south end of Loch
Lomond, not far outside the Trossachs.]