At last we are back to normal oceanic weather patterns with periods of rain, mizzle and a bit of sunshine in between, though it is still a few degrees warmer than usual at this time of year. The plants have responded to the moisture and some summer species are now flowering again into the autumn. Here's a selection of interesting plants I found this month in Cornwall.
On a brief visit to the disused quarry at Trevose Head I found some Slender Club-rush in seed. These can be hard to tell apart from Bristle Club-rush, but the seeds are definitive. I've included some notes on the photo below to assist in ID should you find one.
Isolepis cernua
Some Brookweed was in flower too, with some seeds beginning to emerge.
Samolus valerandi
There were a few other plants flowering, such as Sea Campion and a few Thrift, but mostly the coastal turf took a battering in the drought and most plants won't come back this year. So I headed inland and recorded an area not far from Bolventor on the Bodmin Moor. There were plenty of plants along old and rural road verges as well as on the moor proper.
A Snowberry bush had spread for several metres and almost grown as tall as a tree on a cut off sction of the old A30.
Symphoricarpos albus subsp. laevigatus
Tufted Vetch in flower and fruit.
Vicia cracca
Bush Vetch with fresh flowers.
Vicia sepium
A surprise find on a rural road verge of Wild Basil, not very common on acidic soils.
Clinopodium vulgare
It's worth noting what plants look like as they go to seed so you can still identify them throughout most of the winter months when the flowers are not there to help you.
By a stream were numerous stems of Japanese Knotweed and unusually, it was in flower. Compare these to those of Russian Vine near the end of this blog. The two species can hybridise too, though I suspect those hybrids would require human intervention to enable it to happen.
Reynoutria japonica var. japonica
A roadside Common Figwort had fresh flowers too.
Scrophularia nodosa
There were probably over 100 Marsh Woundworts in flower, but as they have featured in a few blogs this year, here's one in seed.
Stachys palustris
Devil's Bit-Scabious are in flower now and there were some fine displays in a rush pasture and a few days later in pine plantation woodland rides too.
Succisa pratensis
But the highlight of this trip was a simple sowthistle. The verges of the old cut off section of the A30 were full of Perennial Sowthistles and I took a photo of one for Wildflowerhour which is where the public all over the UK and Ireland post on social media what wildflowers they found that week. I was about to post it when I noticed that the involucre had no yellow tipped glandular hairs; in fact, the whole plant was glabrous. I then wondered what it could be and further research found it to be a glabrous subspecies of Sonchus arvensis. On checking ERICA there was only one previous record from Hatt in 2003.
Sonchus arvensis subsp. uliginosus
(Glabrous Perennial Sowthistle)
Of course, I then had to return a few days later to investigate further. I found around 50 more and a scattering of the usual type. This allowed me to take a photo for comparison of the two together.
Other reference material suggested the involucre to be smaller than the usual type and measurements confirmed this too. The usual hairy form averaging 20mm long and the glabrous form 15mm. I noticed that the hairy phyllaries also curled out from the capitulum whereas the glabrous form's phyllaries were tight to it. I also noted, this isn't just a forma or interesting variant, as the glabrous form has quite a lot less chromosomes than the usual type. A first for me!
Another first species for me this day was a Peppermint growing on a disused road verge, clearly originating from dumped garden waste, though it must have been dumped many years past as it was recorded in the same place many years before. It didn't smell very nice but the butterflies liked it.
Mentha x piperita
There's plenty of Narrow-leaved (or Umbellate) Hawkweed flowering now too.
Hieracium umbellatum
Non plant interest included lots of butterflies like this Small Copper;
and a Drinker Moth caterpillar (I think) on a grass stem.
A few days later we were very fortunate to have the BSBI Epilobium referee visit on holiday to Cornwall So myself, David Pearman and Ian Bennallick managed an afternoon out with him and his wife Sarah, looking for Willowherb hybrids. In particular we were looking for any hybrids with the naturalised alien, Epilobium pedunculare, but unfortunately, failed to find any of those. We did find Rockery Willowherb and a few had flowers too, so there is still a possibility that hybrids could be found next year. The white stringy structures about the leaves are the dehisced seed pods of this plant.
Epilobium pedunculare
Rockery Willowherb
A close up of the leaves.
We did find a couple of hybrid plants of Short-fruited x American Willowherbs and I noted from the referee how to identify them in the future, which was handy as a few days later I found several more. I have noted on the photo the main points to look for.
Epilobium x vicinum
The intrepid Epilobium hybrid hunters in action - or having lunch anyway!
A few days later, I visited another coniferous plantation woodland looking for Epilobium hybrids, but apart from more E. x vicinum, I didn't find any, but I did find some interesting plants.
Calluna vulgaris - Heather
Bell Heather, not as common as Heather in the woodland rides, but a few were dotted around.
Erica cinerea
Heath Speedwell was having a second go at flowering.
Veronica officinalis
Trailing St. John's-wort on the path through the woodland.
Hypericum humifusum
Along the grassy edges of the path were lots of Eyebrights, including Confused Eyebright, a multi flexuous branching species that branches from the node just above the cotyledon leaves/scars.
Euphrasia confusa
Goldenrod adorned many woodland path edges and here was no exception.
Solidago virgaurea
All of a sudden, the month was over half way through! I realised it was prime time for coastal Atriplex recording, so I went off to the Torpoint area to have a look around as the tidal Tamar is quite under-recorded for these plant species.
Within a minute of getting out of the car, I found the hybrid between Long-stalked and Spear-leaved Oraches; perhaps the commoner hybrid of upper estuaries. Nearer the open sea you tend to find the hybrid between Long-stalked and Babington's Oraches, but not always!
Anyway, here is a photo of the first hybrid. I did find a larger bracteole with a long stalk around 8mm long on this plant. I've included text in the photo of the key things to look for.
Atriplex x gustafssoniana
Both varieties of Sea Aster were present, rayed and un-rayed. It seems the un-rayed form has fewer chromosomes than the rayed type, but they can and do cross pollinate and back cross leading to an array of intermediate forms. Here's the un-rayed form and an intermediate rayed form.
Tripolium pannonicum
Other salt marsh plants I photographed were:
Long-bracted Sedge - Carex extensa
Greater Sea-spurrey - Spergularia media
And the Sea Rush - Juncus maritimus
Common Calamint was blooming in many places along road verges, paths and the base of Cornish hedges.
Clinopodium ascendens
I was pleasantly surprised at how many Sowbread/Ivy-leaved Cyclamen had naturalised too, they were frequent throughout the area.
Cyclamen hederifolium
A new species for me was Common Galingale on the foreshore which would occasionally be inundated with seawater on higher tides; I assumed this would have been a garden escape in this sort of area.
Cyperus longus
Some Round-leaved Cranesbill were in flower, though I found a patch of leaves first, so I photographed a leaf stem to show the red glandular tipped hairs. Note the dots on the leaf sinuses too.
Geranium rotundifolium
Red tipped glandular hairs
Petals are un-notched.
There were a lot of naturalised Holm Oaks around along the high tide line and inland, but it is rare to see any acorns, though this day I found some I can show you.
Quercus ilex
On a small sea wall on the high tide mark, was a mature New Zealand Flax plant in seed. I've seen these growing in pavement cracks and walls in Newquay and they're on sale in local retail outlets too. I am also told they are widely naturalised on Scilly too.
Phormium tenax
One of the yellow Melilots was flowering on some waste ground, so I've added a few points to the photo so you can tell Ribbed and Tall Melilot apart.
Melilotus altissimus
This is Cangapool, a shallow bay on the tidal Tamar that dries out when the tide recedes and where I found many of the plants shown above. Devonport Dockyard is in the distance.
A brief walk at Par Sands didn't find me any new species, but there's always interest there as it is so botanically diverse. Here's a few plants from this short walk.
Frosted Orache with its woolly hairs on all parts that make it look like it's just been brought out of a freezer! It is usually found not far from the high tide mark.
Atriplex laciniata
The yellow flowers of Wild Fennel appear identical to those of Wild Parsnip, so remember to check the leaves which are finely dissected in this species, and not so in Wild Parsnip.
Foeniculum vulgare
Evening Primroses can be difficult to work out if you follow the taxonomy in the BSBI field guide for Oenothera. However, Stace simplified them and this is Common Evening Primrose as the stamens and stigmas are more or less equal in length and there was no red spotting on the stems or sepals (which could indicate a hybrid O. x fallax or O. cambrica if not subsumed within O. biennis).
I had noticed that O. glazioviana or Large-flowered Primrose had flowered here in June but was absent now; the hybrid, O. x fallax had flowered here in July and was also now absent, and now in September these were flowering. Another adaption was that these were mostly under one foot tall due to the recent drought no doubt, but the flowers remained the usual size.
Oenothera biennis
The Sea Daffodils here were now in seed and below shows a photo of the pods, some had been broken into and the seeds were missing, presumed eaten by slugs perhaps. They are designed to float and drift off on the highest of tides to colonise other beaches.
Pancratium maritimum
Sea Knotgrass was doing amazingly well with a lot of plants seen; some up to a metre in diameter, plastered with their large (for the genus) crowded flowers.
Polygonum maritimum
Tall Rocket was still flowering on recently cleared of scrub dunes. I recorded these here last year but here's something interesting about the species. They were first recorded here in 1901, 1910, then 1929 and nothing until 2025 (source: ERICA) when the dunes were cleared of scrub back to bare sand.
Hundreds of S. altissimum then appeared potentially evidencing a long-lived seed bank. They'll probably disappear again as the dunes vegetate over again. The stem and basal leaves are more finely cut than S. orientale with which they could be confused with, as both species have long, curled pods.
Sisymbrium altissimum
Still at the seaside, but this time at Constantine, I found some more interesting plant species.
Musk Storksbill was in flower on a sandy pavement.
Erodium moschatum
Sea Storksbill was nearby, but it had no flowers out. If it did, they have no petals anyway! The smaller flowers of Common Storksbill were also found but not photographed.
Erodium maritimum
A seeding Sea Holly looked quite autumnal in the dunes.
Eryngium maritimum
An individual flower of a very fast growing naturalised Russian Vine (see the Japanese Knotweed flowers above for comparison).
Fallopia baldschuanica
Here's a small part of the whole plant!
A new record for Constantine was Vervain, with over 100 plants flowering along a sandy road verge.
Verbena officinalis
At the end of the month, I found a Marsh Yellow-cress in the car park of the lower Tamar Lake. Noteworthy as it hadn't been recorded here since 1984. Having said that, plants like Spear and Marsh Thistles, Common Ragwort and Common Chickweed were all new records too! It just shows that you should record everything you can, as you never know what common plants are missing from the monad you're recording in.
Rorippa palustris
That concludes my plant finds in Cornwall for September. I may combine the next three months into one blog as the year draws to a close, but I will see what I find each month before I decide on that. Until then, goodbye.
Regards
Dave
