Rubus fuscicaulis – Series Radulae
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This is one of a confusing group of glandular brambles with white-petalled flowers and red styles which belong to the R. fuscus aggregate
. Other similar species (not yet covered on this website) include R. trichodes (Series Micantes), R. anglofuscus (Anisacanthi), R. largificus (Radulae) and R. murrayi (Hystrices). There is also the true
R. fuscus which has pale pink petals. Useful field characters for identifying R. fuscicaulis include the usually small rounded head of flowers, broadly elliptical to obovate terminal leaflets and hairy, glandular stem. It is widespread in Ireland and is known from the southern part of the Welsh/English border and north Somerset, with scattered records across southern England. It is also found in Belgium. These photographs were taken of plants in Hampshire, Somerset, Wiltshire and Hertfordshire.
It is a low-growing to medium-arching species with a rather compact, stoutly branched, short cylindrical or rounded inflorescence. The rachis is flexouse (i.e. somewhat zigzag), green or turning reddish, densely pubescent and with numerous short glands and acicles, and some slender prickles.
Flowers are small, about 2 (-2.5)cm diameter with broadly elliptical white petals, up to about 11 x 8mm. These photos show the petals to have small notches or teeth at the apex. Styles are clearly red-based; the stamens are distinctly longer than the styles (though published descriptions state they can be level to slightly longer). Anthers are glabrous; carpels and receptacle hairy. Sepals are felted on both sides, sharply pointed, indistinctly white bordered on the outside, with red glands and acicles. Sepals are loosely reflexed to patent after flowering.
Leaves are mid green in colour, somewhat matt in appearance, sparsely hairy above (with a rough feel), flat, with sharply serrate, slightly undulate margins. Leaflets typically three, but sometimes five, or three with the basal ones fused to the laterals; not contiguous when in threes.
The terminal leaflet is about 8 x 5cm, broadly elliptical or slightly obovate, with an emarginate to sub-entire base and a relatively long acuminate tip.
The dark reddish-brown colouration on younger leaves may be a distinctive feature of R. fuscicaulis (as it is with several other brambles).
Leaflets are softly hairy and paler green below, but not strongly felted.
The stem is bluntly angled with flat or weakly furrowed sides, dark reddish purple with frequent slender main prickles on the angles. The elongated base of the prickles tapers gradually into the fine, needle-like yellow tip. The prickles vary in size from shorter to slightly longer than the stem diameter and are almost patent to declining or less often curved. On the faces there are frequent to abundant gland-tipped pricklets and acicles - these are all fairly even in length which give the stem the rough feel and appearance of a typical Radulan. The stem is also densely pubescent, with hairs roughly 1mm long and about the same length or longer than the glands.
