Rosa canina (Dog-rose) identification.

Rosa canina (Dog-rose) identification.

With R.canina agg. being split into  three species, R. canina, R. corymbifera and R. squarrosa I thought I would take a few photos of a 'perfect'  R. canina (or R. canina stricto sensu) in Cambridgeshire.  

The main problem is finding an example of R. canina s.s. which conforms to the new handbook description and does not show features of the two northern dog-roses or R. corymbifera and R. squarrosa.

I don't want an example which has:-

Glaucous coloured underside to leaves or folded leaves.

Zig zag stems.

Stems that show a red colour.

Short pedicels suggesting hybrid with Northern Dog-rose.

Short pedicels with large bracts that obscure the pedicels. R. canina s.s. should have pedicel length in the range 1-2.5cm whereas northern dog-roses should be in range 0.5-1cm and the hybrids could be anywhere, but I would like an example with some pedicels at least 1cm. 

Large hips especially if round/spherical.

R. canina s.s. should have a 'temple dome' shaped uni-serrate margin to the leaves without any glands, so NO glands.

Soft hairs or glands on the petiole/rachis. 

Odd looking prickles.

Leaf stipule glands that stay on and are round rather than slightly elongated.

That's probably enough features I don't want, but there are probably more. This proved quite hard as most R. canina potential plants failed, for one reason or another. 

Pedicel has no glands. A key feature of the Dog-roses.

My selected potential R. canina growing in Wicken Fen.

Erect and arching stems.

Pedicel has no glands and is over 1cm, not enclosed by bract.

Sepal is pinnate and should not have too many secondary side projections or too many glands to be acceptable for R. canina.   Sepals of the three dog-roses R. canina, R squarrosa and R. corymbifera become reflexed as the hip ripens and fall off early.   Sepals of R. squarrosa might have more glands on the tips of the pinnate side projections.

Orifice is narrow and the disc is conical. A conical disc is very common in Cambridgeshire for R. canina.  Sometimes this conical disc is given the name R. canina var. spuria according to the new handbook. The orifice is deep and has vertical groves from forming around the style. 

Next photo shows the sepals have already become reflexed even though flowering has only just finished and the hips have not started to turn red. The rate that sepals move seems very variable even on a single plant but the fact that on this plant they have reflexed early is a good sign for R. canina.

Next the leaves. Green on top and flat not folded.

The leaf has several important features to consider. 

Uniserrate margin with hydathodes only, no glands.

Underside not glaucous just a paler green. Margin is uniserrate, no glands.

Petiole and rachis has no glands or hairs on. A key feature.


Leaf stipule.

The leaf stipule glands are falling off and the remaining ones are elongated in shape which conforms to Tony O'Mahony's discovery that roses in the subsection caninae ( Dog-roses) have these features. See previous blog that covers this subject. I always pick a new leaf from a new shoot for this test if possible.

Prickles.

It often surprises me the variation in prickles on a single bush but the above conform to what I would expect for a R. canina, in that they have a broad base and are variably hooked. I have seen quite a few potential plants of R. canina locally, near Swavesey, that have very straight prickles which don't look right and suggest some introgression, but what with, is a puzzle.

Conclusion.

The above photos I think are a good example of what a Rosa canina should look like at the post flowering stage. The well known problem that every Dog-rose bush looks slightly different, so you have to accept quite a lot of variation but where to draw the line and decide it no longer fits the 'perfect' R. canina is a challenge.  Some introgression is allowed, otherwise very few roses would be identified beyond R. canina Agg.

Finding a good example of R. canina was quite difficult as most plants have features that could indicate more than a little introgression with another, now separated species, either R. corymbifera, R. squarrosa or more frequently R. vosagiaca / R. caesia. Hybrids with species outside the Sub-group caninae also occur and another rose bush at Wicken Fen seemed to some features of R. rubiginosa with large glands on the underside of the leaves and just the odd acicle.

The above is a personal view but based on the new BSBI Rose handbook which was published in late 2025.

Peter Leonard

Cottenham, Cambridgeshire.

July 2026