Rubus thyrsigeriformis – Series Hystrices

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This bramble was known from Southampton Common and other parts of southern Hampshire by the Rubus specialist David Allen, who by chance came across a specimen in the British Museum herbarium from Cherbourg, France (at the time under a different name) which he realised was the same taxon. He later visited that locality and refound it. The details were published in the journal Watsonia in 1989, too late to be included in Edees and Newton's Brambles of Britain and Ireland (1988). More recently it has been found to be widespread in the Bath and Bristol area. It may be a relatively new arrival to this country. The photographs here were taken of a single bush and the description is based on this and two other specimens. It is quite a distinctive member of the Hystrices, with narrow, bright pink notched petals and deep red styles.

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The petals are widely spaced with large gaps between them, about 7-8mm wide but varying from between about 11-15mm in length (rarely longer than this) and notched at the tip. The sepals have long narrow leafy tips which are patent or mainly reflexed at flowering, with some becoming erect after the petals have dropped. The panicle branches are rather long and slender and widely divergent, adorned with numerous fine prickles and abundant stalked glands and hairs.

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The stamens are short and rather sparse, so hardly obscure the red styles, which have yellowish tips.

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Leaves are usually 3-foliate, but some have lobes on the lateral leaflets where the basal leaflets would be. Leaflets are almost glabrous to sparsely hairy above and a little more hairy below. The terminal leaflet is obovate with a deeply serrate (incised) margin above, nearly straight sides below and a long finely acuminate (mucronate) apex.

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The stem has a typical Hystrican armature, with prickles varying in size, without obvious main prickles confined to the angles and with frequent small prickles (pricklets) on the faces. There are numerous stalked glands and sparse, long hairs.

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