A rare member of the Sprengeliani, somewhat similar to R. sprengelii, but with broadly ovate leaflets. It has a similar low-growing habit, with thinly hairy stems, 3-5 leaflets, a widely divergent weakly armed inflorescence and deep rose-pink petals.
Rubus permundus was described as
plentiful over a large area under bracken at Netley Heath, Surrey, by W.C.R. Watson in his Rubi of Great Britain and Ireland. I am uncertain as to why this single colony was given a scientific name, since usually brambles are only named if they are established over a reasonably large geographical area. The colony pictured here was discovered at the north end of Browndown Common, Gosport, Hampshire by David Allen and myself in 2012. The colony occurs under bracken in a heathland area, close to the edge of a river. R. sprengelii grows nearby, which suggests that possibly R. permundus could be a hybrid of that with another species.
The flowers are distinctly larger than those of R. sprengelii, about 2.5 cm across with broadly obovate petals. Styles are deep red and the stamens are pink at the base.
A feature of the Sprengeliani is that the stamens are about equal to the styles; in these flowers the outer ones are distinctly longer (it is difficult to assess in the second photo below, because it is not fully opened). Note also the sharply pointed patent sepals (similar to R. sprengelii). The lower flower in the first photo also has long leafy sepals, a feature mentioned in Watson's Rubi.
Leaves are almost glabrous above and roughly hairy below on the veins. Three or five leaflets may be present (or three with budding lobes). The description in Edees & Newton that the leaves are
somewhat plicate does not seem to be true of these plants, but may apply to specimens in full sun. The terminal leaflet is broadly ovate with a short to medium length acuminate tip.
Leaflets are thinly hairy below (mainly on the veins).
The stem is rather stout, bluntly angled to almost round, turning reddish purple in sun, thinly hairy with fine, broad-based, declining prickles. Descriptions state that rare short-stalked glands may be present.