Cornwall Botany - 1st-16th July 2025

 The first two weeks or so of July has seen the country suffer a heatwave with temperatures over 30 degrees and commonly in the high 20s for days on end. This gave rise to drought, with even Wood Docks wilting in the woods. The weather has only just given way to cooler temperatures with some drizzle. Hopefully, the surviving plants will get enough water to survive the next heatwave forecast later this month. Here's some of the plants I have seen in the first half of July. 

First off was a trip to Tregonetha Downs, West of Bodmin. I chose to record the under-recorded Eastern end which was very overgrown with Western and Common Gorse. At the end of it I had around 100 small punctures and cuts to my lower legs where the spines had gone straight through my jeans. Sometimes the scrub was waist high and was very hard going in the heat. After this, I thought it prudent to get a tetanus jab, as the last one I had was over 40 years ago!

 There were still  a few Heath Spotted Orchids in flower which was nice.

Dactylorhiza maculata subsp ericetorum 

 

 Bell Heather coming into full flower now - Erica cinerea

 

Cross-leaved Heath dominated much of the heathland.

Erica tetralix

 

In one of the few damp areas, Marsh Bedstraw was flowering. It looks very similar to Fen Bedstraw, but Marsh lacks mucros (bristle points) on all leaves, and the stems only feel rough in one direction not two.

Galium palustre

 

 Common Yellow Sedge was abundant in places. Its fruits are very similar to mini pineapples and all fruiting clumps are stalked.

Carex demissa 

 

A few Bog Asphodels were hanging on in a few damp areas not swamped with Gorse (yet).

Narthecium ossifragum 

 

Lesser Skullcap from the same damp area.

Scutellaria minor 

 

On the road verge by the heath were some Marsh Woundworts in dappled shade.

Stachys palustris 

 

The final plant of note was on dumped spoil by the roadside. There was easily over a ton of soil, so it was likely either placed there by a farmer or a tipper lorry dumped it here. It was reasonably vegetated, so it had been here a while. Growing by it was some Cornfield Knotgrass, one of the rarer species in this difficult group. The photos show the key characteristics of this plant. It also has an upright habit or may creep along the ground before rising upwards.

Polygonum rurivagum

 

A few days later I was recording a monad near Week St Mary.  After much searching, I found Broad-leaved Helleborines in a dark woodland, last recorded here in 1998.

Epipactis helleborine

  

Common Cow-Wheat was abundant in one part of the woodland here.

 

Melampyrum pratense subsp pratense

 

I usually find Ivy-leaved Water Crowfoot in the Spring, so it was nice to find some flowering in a series of large puddles caused by cattle on a footpath.

Ranunculus hederaceus

 

In the same puddles, I noticed some thicker than usual Duckweeds, so I took a good look at them and found them to be Fat Duckweed. On returning home I discovered the species had been rejected for Cornwall, though I don't know why. As such, I sent the photos to the BSBI referee for Lemna and he confirmed this was indeed Fat Duckweed. Clearly it is present in Cornwall and some older records will now be reconsidered. Until they are, this find remains a first for Cornwall.

The undersides of the leaves often have inflated cells clearly distinguishing them from Common Duckweed which has lots of tiny cells. Both have just one rootlet attached.

 

Lemna gibba

 

 

On a side view you can clearly see the underside is enlarged and not flat.
 

I managed an hour at Par Sands for a walk and noted some nice species, including one new to the area. In recently cleared of scrub dunes, hundreds of Tall Rocket were flowering. They have very long curled seed pods and they looked rather like Eastern Rocket with which I am familiar. However, the stem leaves  were finely divided (pinnate) which was wrong for that species. A first for me too with this species.

 

Sisymbrium altissimum

 

 The rosette leaves were different too, being narrower than Eastern Rocket.

 

 

There are three previous records for Opium Poppy here, two from the early 1900s and one from 2021, however, the one I found this day appeared to be a garden variety, likely the variety called "Pink Chiffon" which is a double flowered form, so another first for the dunes.

 

Papaver somniferum "Pink Chiffon"
 

Wild Parsnip does well here. It's the only yellow flowered umbellifer with large pinnate leaves, making ID easy. However, there are three subspecies to consider too. The wild one (below) has strongly angled stems with hairy leaves and stem and no swelling at the base of the stem. A lookalike, the Garden Parsnip (subsp sativa), has a swollen base and is almost glabrous (hairless). The third species is continental (subsp urens) and has recently colonised the M20 in Kent, probably from lorry movements, that one has round stems.

 

Pastinaca sativa subsp sylvestris 

 

 

Several hundred Haresfoot Clovers were mostly in seed on the eastern part of the dunes. I don't know why they haven't spread to the western areas though.

 

Trifolium arvense
 

 

Sea Knotgrass is our only perennial knotgrass, and it lays buried in the sand until Summer when it comes up to flower. The first few spikes were coming up out of the sand. Note the heavily curled over leaves and clumped flowers separating it from Ray's Knotgrass.

 

Polygonum maritimum
 

 

Sea Daffodils were discovered growing here a few years ago and there was much debate as to how they arrived. It seems likely now that someone discarded seed here some years back after a trip to the Mediterranean area. There is an older colony at Marazion where they may have arrived naturally from Brittany, no-one really knows for sure. I was about a week too early for the first flower which was still in bud.

Pancraticum maritimum
 

A few days later I took a walk around the Kerdroya labyrinth on the Bodmin Moor. I visited here in the Spring and found many new species to the area, no doubt introduced when the labyrinth was built. It is comprised of many sections of Cornish hedge which are earth filled walls, using stone from all around the county, including Serpentine rock from The Lizard area, so anything could turn up here.

 

The first new plant was Purple Bugloss, previously recorded near Sennen Cove in the West of the county. However, this appeared to the blue flowered form, which is commonly found as garden escapes or in wildflower mixes ( source: http://webidguides.com ). There were no other alien species in that section, so it's a bit of a mystery where it came from.

 

Echium plantagineum "Blue Bedder"

 

 

The flesh coloured flower form of Scarlet Pimpernel, common on The Lizard, but a first here for Bodmin Moor I suspect.

 

Lysimachia arvensis forma carnea
 

 

A normal coloured Scarlet Pimpernel growing with Trailing St. John's-wort

 

Hypericum humifusum

 

 I noticed a tiny white flower on one of the Cornish hedges and found it to be a drought stricken Thyme-leaved Sandwort. If it has needle like leaves consider Slender Sandwort (Arenaria leptoclados) which also has cylinder like pods rather than the flask like ones in Thyme-leaved.

 

Arenaria serpyllifolia 

 

 On another wall was a small colony of Alsike Clover. It differs from red and white clover in having unmarked leaves with many branched veins; the stipules taper into a long point; there are no leaflets directly under the flower and the colouring is typical as shown in the photo below.

 

Trifolium hybridum

 

 I rounded off the first half of July with a visit to a part of Cornwall, West of the Tamar, that is in botanical Devon (VC4), to a small village called North Petherwin. A variety of habitats enabled me to record almost 190 species of plants here. The area had only been recorded three times in the 21st Century, so it was good to update and find new records there. One of the best places in the monad for species was the old Otter Sanctuary, now the Willowtree Cafe. Parking is free and after a nice lunch in the friendly cafe, you can walk the woodland and ponds that used to be the otter reserve.

 

In the car park, I found 5 spikes of Broad-leaved Helleborines, but surprisingly, I found a further 18 bigger spikes near the ponds in the grounds. They are always lovely to see in this part of the country as they are nowhere near as common as they are in other parts of the UK.

 

Epipactis helleborine

 

 

The most commonly seen pollinator of Helleborines is the Common Wasp, and one alighted onto the flowers while I was trying to photograph it.

 

 

Another rare plant for Cornwall was the Wood-club-rush. There were several hundred flowering spikes in one of the ponds. 

 

Scirpus sylvaticus

 

 Their stems are thick and strongly triangular.

 

  

 Forget-me-nots that grow in water can be tricky to identify, though only two (Creeping and Tufted) have small pale blue flowers, the other, Water Forget-me-not has larger, deep blue flowers. I've added text to show you what you need to look at to separate Creeping and Tufted Forget-me-nots, so always look under the flowers at the sepals; the hairs at the top of the stem and at base of the stem where they may be different (as here). I usually find Creeping Forget-me-not in acidic bogs, but it was quite at home around the disused otter pools and ditches. It also has stolons, though these aren't visible unless you uproot a plant. Species like Hard Fern were also present, indicating some acidity to the soils here too.

 

Myosotis secunda 

 

 The ponds also had a large population of Curly Waterweed, a species that doesn't look much like anything else, so easily remembered. It's green in early Summer, turning brown as they age. It's quite common in the Bude area too.

 

Potamogeton crispus 

 

 Common Hemp-Nettle on a woodland ride.

 

Galeopsis tetrahit 

 

 

 That rounds off the first half of July, I hope you liked the selection of plants from Cornwall. With the cooler, wetter weather of late, I am hopeful that the Summer plants will perk up for the second half of the month. Until next time.

Dave