Drosera rotundifolia × D. anglica
(D. × obovata Mert. & W.D.J.Koch), a hybrid sundew

Native, extremely rare, but probably under-recorded. Eurosiberian boreo-temperate.

July 1949; MCM & D; bog at Meenatully Td, near Lough Vearty.

This hybrid has been recorded only once in Fermanagh, growing with both parents on a flat bog at Meenatully near Lough Vearty in July 1949 by Meikle and his friends (Carrothers et al. 1950). The leaf-blades of this hybrid are more similar to D. intermedia than to either of the parent species, but it has a ± centrally arising inflorescence peduncle, which like that of the parent species is straight. Apart from this, the hybrid also differs in being completely sterile, having small, empty capsules. Unfortunately in many sites the proportion of Drosera plants bearing flower scapes is often quite low, making it very difficult or almost impossible to distinguish the hybrid. The hectad map in the Hybrid Flora of the British Isles, shows the range of D. × obovata covers most of the joint range of the parent species, with by far the greatest recorded frequency of the hybrid in B & I being in NW Scotland (Stace et al. 2015). The same map indicates that in Ireland, the hybrid has been recorded in a total of 27 hectads, 21 of which also contained both parents. Both parents plus D. intermedia are regularly, indeed rather frequently recorded together on the same bog surface in Fermanagh. Obviously the hybrid should be actively looked for each time the parent species are found growing immediately adjacent.

The fact that all three Drosera species occupy very similar wet, acid bog situations, means that the shape and size of the leaves alone would not enable the hybrid to be discriminated from D. intermedia. Robert Northridge and the current author therefore have no doubt that D. × obovata is being regularly overlooked in Fermanagh and elsewhere. However, while we cannot tell the extent of such errors, we do know that in Britain this hybrid nowadays is usually regarded as relatively frequent, although it remains under-recorded (Stace et al. 2015).

In the Lough Neagh area, Harron (1986) mentioned just one very old (mid-Victorian) record at Sluggan Bog near Randalstown (given as 'Slogan'), undated but listed by David Moore in Cybele Hibernica − before the plant was fully recognised as being a hybrid (Moore & More 1866). The FNEI 3, however, lists three post-1969 sites for this hybrid in Co Antrim (H39) (Hackney et al. 1992).

In NE Scotland, Mary McCallum Webster's Flora of Moray, Nairn and East Inverness, has the author describe this hybrid as, "frequent where both parents occur". Closer examination of this particular Flora, however, indicates that a total of only ten sites are listed for the hybrid in the large geographical area covered, three of which have 19th century dates only (McCallum Webster 1978). Whenever D. × obovata is found, typically it occurs either as isolated individuals or in very small numbers.

Still we have to recognise that on account of the similarity of D. × obovata to D. intermedia and also to small plants of D. anglica, this hybrid is very easily over-looked.