Rubus idaeus L., Raspberry
Account Summary
Both native and introduced, an escape from cultivation. Very frequent. Circumpolar boreo-temperate, but widely cultivated and naturalised.
1866-72; Stewart, S.A.; Fermanagh.
Throughout the year.
Growth form and preferred habitats
Suckering shrubs with biennial canes ranging from straggly to upright and from dwarf to tall, 100-200 cm in height. Wild strains tend to have many short, thin canes in comparison with cultivated varieties and varying quantities of needle-like prickles. Leaves are also very variable, in shape and indentation of the leaflets which can number 3-5(-7), green above, chalky white and soft beneath, with dense stellate hairs (Haskell 1960; Edees & Newton 1988; Sell & Murrell 2014). The species often occurs in open woodland or scrub, on heaths, or less often in hedgerows. In upland areas, it occurs on base-rich cliff ledges and at the base of such rock faces. It also appears on waste ground and rough grassland as escapes and in quarries and other areas where garden rubbish has been tipped. The species is said to prefer sandy or well-drained soils (Edees & Newton 1988), although from the wide range of sites it occupies in Fermanagh, this is not exactly obvious!
The origin and status of many colonies, either as native or a cultivated introduction, is sometimes difficult or impossible to determine by inspection. However, the British authorities, Edees & Newton (1988), are definite in stating that R. idaeus is, "certainly native in many places particularly in hilly districts in the north." Since Raspberry is frequently bird sown, even the site and habitat give little clue as to which we are dealing with. As might be expected, the fruits of wild plants are generally distinctly smaller than those of cultivated varieties and, unlike the latter, they are mostly a deep purplish-red colour when ripe (Haskell 1960). After a few years in the wild, however, escaped cultivated plants inevitably suffer virus attacks and they then revert to forms bearing smaller fruits, thus becoming inseparable from their wild cousins. However, in some apparently wild plants the fruits were not only large, but had the good flavour and the appearance of a cultivated variety, making it impossible to tell their origin from an inspection of the fruit alone. Plants of the two origins (wild and cultivated) also hybridise and genetically introgress, compounding the problem of identifying their status (Haskell 1960).
Male plants are readily recognised by their distinctive foliage (leaves simple or 3-foliate, leaflets imbricate, suborbicular, reniform, with broad crenate teeth) and by the rounded shape of their flower buds (Edees & Newton 1988)). A simple two-gene switch controls sex in the species: MF plants are hermaphrodite and Mf plants are males. The limited survey of wild R. idaeus populations by Haskell (1960) showed that the gene for male plants is widespread across Britain, stretching from W Norfolk to Inverness.
Despite the above concerns, R. idaeus is regarded as most likely or even certainly native in the hillier, more remote districts of B & I and especially so in the most northerly regions of Scotland (New Atlas). In addition to seed production, dispersal and establishment, Raspberry plants commonly sucker from the roots and spread locally, particularly in more open or rocky, base-rich sites, forming dense prickly clumps or thickets (Edees & Newton 1988, pp. 18-9).
Fermanagh occurrence
In Fermanagh, R. idaeus is frequent and widespread, present in 266 tetrads, 50.4% of those in the VC. It is found on the margins of woods, on cliffs, in hedges, on heathland and the drier edges of bogs. Raspberry also occurs quite frequently as a garden escape or discard on waste or rough ground near habitation, when its origin is unambiguous.
Irish occurrence
R. idaeus is very widely distributed in Ireland, but the New Atlas hectad map indicates, even at this coarse level of resolution, that it is less prevalent down the west of the island (Preston et al. 2002). Presumably this is due to the wetter, very acidic, peaty soils that predominate there.
British occurrence
In Britain, R. idaeus is very frequent and widespread almost throughout, the main areas where it is less prevalent being fenland around The Wash, the far north of Scotland and a limited number of scattered coastal sites (New Atlas). Again, since it is so widely cultivated, it is often impossible to be certain of the origin of the plants recorded.
European and world occurrence
R. idaeus s.l. is a polymorphic species with a wide Euroasiatic and N American distribution. Subsp. idaeus is widespread throughout most of Europe, but only on mountains in the south. Beyond E Europe it also stretches across from the Caucasus and Turkey to W, N & C Asia where subsp. melanolasius Focke continues eastwards through most of E Asia. It also occurs over large areas of N America. R. idaeus s.l. belongs to the circumpolar plants and has been introduced into eastern N America, Greenland and New Zealand (Hultén & Fries 1986, Map 1053; Sell & Murrell 2014).
Threats
None.