Cornwall Botany - September 2025

 Autumn has arrived well before the Autumn equinox, with lots of wind and rain, completely breaking the Summer drought. Back to normal weather for Cornwall then! The extra moisture has enabled Summer plants to carry on and the Autumn plants to get a good foothold too. Here are the highlights of what I found around Cornwall in September.

 

A trip to Rock Dunes gave the last remnants of this year's final wild orchid to flower, Autumn Ladies Tresses. I only found three left in flower.

Spiranthes spiralis

 

Some Wild Clary was flowering on a pavement in Rock village.

Salvia verbenaca

 

For some reason Rock has an abundance of the white flowered form of Common Storksbill, as well as plenty of the usual pink flowered form. I did search for Sticky Storksbill, but couldn't find any likely candidates.

Erodium cicutarium

 

 

Portland Spurge likes it here too, it grows on the cliffs, on walls and on the sea wall. It is easily told apart from Sea Spurge (also growing nearby) by having bracts around the flower parts shaped like a pair of Ace of Spades; it's often branched with multiple inflorescences, and may be somewhat procumbent in habit; the stems often turn red. 

Sea Spurge has bracts more oval in shape, is usually upright and little branched with green stems. If branched, all branches are erect at an acute angle to the main stem. The inflorescence is always at the top of the main branch in a tight cluster and not spread out like Portland Spurge (see 2nd photo below).

Euphorbia portlandica

 

A walk along a rural path near St. Columb Road led to a damp meadow and in the corner was a small colony of Wavy-leaved St. John's-wort. This species is confined to Devon and Cornwall and a few sites in Wales. It has more golden flowers than most other Hypericums and the underside of the petals are streaked with a bright crimson colour. If not in flower, the leaves, as the name suggests have wavy, crinkled edges, not straight like the other species have.

Hypericum undulatum

 

Of course, early Autumn is the time to look for Glassworts and coastal Orache species. I have taken to properly identifying those I find as they can be challenging. Likely species are Long-stalked Orache; Spear-leaved Orache; Babington's Orache, Common Orache and hybrids between all of them except the last species which is genetically incompatible with the others. This involves checking mature bracteoles on each plant and determining what species they belong to or whether a hybrid is suspected. My personal opinion is that there are many hybrid swarms of Long-stalked x Babington's Orache and Long-stalked x Spear-leaved Oraches in our estuaries, all showing intermediacy in their characters. For anyone that would also like to be able to identify these, have a look at BSBI News 139 Sept 2018 where there is an in depth article on them and how to determine what species or hybrid you may have found. There's also a good key in Stace 4 that you can use. If you find one, take a sample of the bracteoles including axillary ones (growing in the stalk) for closer study.

Here is a typical suspected hybrid plant between Spear-leaved and Long-stalked Oraches, later confirmed by the BSBI Atriplex referee.

Atriplex x taschereaui

 

Whilst looking at these interesting Atriplex plants, I noticed a very tall Dock plant in the saltmarsh. I was fairly confident this was Saltmarsh Curled Dock, and it was later confirmed as such by the BSBI referee. This makes it the second estuary site for Cornwall and the first from a south coast estuary. The key points in identifying this sub species are:

The height of the plant, between 1.5m to 2m tall - in this case 1.90m tall;

A lax infructescence, with branches not tight to the main stem;

3 sub equal nutlets, 2.5-3.5mm long - in this case 3mm. 

Habitat, upper saltmarsh. 

Again, there is a good key for these in Stace and the BSBI Docks Handbook. 

Rumex crispus subsp uliginosus

 

Along the coast path in the wooded areas, Goldenrod was still flowering nicely. A hint I can give for later in the year, is to note the leaf arrangement in flowering plants now when you easily recognise them, then when you see them gone to seed, you will still be able to recognise them from your earlier observations. If you have a good memory, you will also recognise them before flowering next year.

Solidago virgaurea

 

The recent wet weather had brought our quite a few fungi too.

Parasols - Macrolepiota procera

 

Poor Man's Liquorice - Bulgaria inquinans

Beefsteak Polypore - Fistulina hepatica

 

 

Hops are uncommon in Cornwall, but I found a great big colony crawling all over scrub by an estuary near Penryn.

 

Humulus lupulus

 

 

 On a family trip to Newquay (shopping of course), I wandered off and noticed an odd looking palm like plant growing out of a wall. It turned out to be a Cabbage-palm, clearly self sown given its location. It's amazing what can grow in the wild in these frost free coastal locations. A few days later, I saw lots of these plants for sale in the big retail stores, so I expect I'll see more of them in the future too.

 

Cordyline australis "Variegata"

 

 

On the coast path at West Pentire, I found a flowering Thorny Olive Tree growing by the path, almost on the cliffs. There were no gardens or habitation nearby and no other alien plants, so I don't know how it got here. It was either planted many years ago by someone or was perhaps bird sown. The second photo shows the trunk of this tree, showing it's a very old tree.

 

Elaeagnus pungens 

 

 

West Pentire is known for its fine collection of rare arable plants and though it was late in the year, I managed to find a few species hiding away under the larger species and crop plants that had seeded. Here's Weasel's-snout, a tiny arable form of Snapdragon.

 

Misopates orontium

 

 

 Corn Marigold was also present, though only a very few were still in flower.

 

Glebionis segetum

 

 Corn Spurrey, this was the only one I found in flower still.

 

Spergula arvensis 

 

 

 

A Field Pansy looking lovely in the sunshine.

 

Viola arvensis 

 

  

 

On the way back from here, I stopped off in Newquay to look around the verges of a new road and an adjacent area that had been cleared for future house building. I found near on 150 species in this area, so it's unfortunate they will all be destroyed soon. However, very few of them would be present at all if the site hadn't been cleared, so it's swings and roundabouts in these situations.

 

There were hundreds of Field Woundwort flowering all over this area. This is a Near Threatened species in England. The reddish flower next to it is Scarlet Pimpernel.

 

Stachys arvensis 

 

 

 

I found a rosette of Birdsfoot, which in season, has tiny white, yellow and pink pea like flowers. Unfortunately, I couldn't find any flowers on this one. As the year ends, recording species I see, often relies on looking at vegetative characters, such as rosettes, so it's a good idea to memorise those around now that are in flower, so you can identify them over the winter, when there are no flowers to help you.

 

Ornithopus perpusillus

 

 

In one area I found several Lesser Quaking Grasses in seed. Don't be fooled by the name, this grass can sometimes grow around two feet tall. The florets are smaller and (when not dead) light green in colour, distinguishing them from the more usual Quaking Grass found on calcareous soils further East.

 

Briza minor

 

 

Clearly self sown, this Argentine Vervain was growing on spoil moved around the site at some time by machinery. I've recorded them before on pavements and industrial estates too.

 

Verbena bonariensis 

 

 

My final plant from here, and for the month, was Grass-leaved Orache, of which there were over 50 plants along the road verge. This is usually a salt marsh plant, but is spreading around the UK on salted road verges and I used to find it a lot in North Kent years ago. However, they look very similar to Common Orache, so a detailed look at the bracteoles and leaves is necessary to confirm it. In this case, all the leaves, including basal leaves were strap shaped, lacking any pointed side lobes and all leaves had a cuneate base (tapering to the base) and the bracteoles were spot on for the species (see Stace 4). I took a sample home to key it properly.  It's the first time I've seen this species in Cornwall, though it is found on occasions.

 

Atriplex littoralis

 

 

 

 That wraps up my September finds. I wonder what I might find in October? See you then.

Dave