Teesdale’s special plants are declining

Over the winter I compared our survey results from 2017 to 2019 for 19 of the special plants, to results from a survey from 1968 to 1975 of the same species in the same areas on Widdybank Fell. I was shocked by what I found. All 19 species have declined in extent! On average, these species were not found in over half of the areas they grew in 50 years ago.

The map below shows the situation for Spring gentian Gentiana verna. In the area shown, towards the upper end of Red Sike, Spring gentian was mapped in all of the orange squares (638 squares) in the older survey. Each square is ten metres by ten metres. The blue dots show which squares (353 squares) we found it in from our more recent survey. The yellow squares show which other squares were searched, but did not have any Spring gentian either time.

Spring gentian records along Red Sike from two surveys

There are some blue dots on yellow squares, meaning that we found it in the last few years in some areas where it was not found in the original survey. But there are many more orange squares with no blue dots, meaning that we did not find it in many areas where it was present before. Overall there has been a 45% decline in the number of squares occupied by Spring gentian between the two surveys.

Several of the other special species have suffered even worse declines in extent. Alpine rush Juncus alpinoarticulatus has declined by 85%, mountain everlasting Antennaria dioica by 81% and northern bedstraw Galium boreale by 62%.

Mountain everlasting has declined in extent by 81% on Widdybank Fell since the early 1970s

The map below shows how many of the special species have been lost from different parts of the upper half of the Red Sike area. The darker dots are in the squares that have lost more species. The full extent of the sugar limestone habitat along red Sike is not shown on this map, but overall the trend is that more species have been lost from areas of sugar limestone habitat further into the fell and away from the track.

Numbers of special species lost from upper Red Sike area

The grazing intensity on the fell has been much lower in the past 20 years or so compared to previously and the vegetation in the sugar limestone areas is no longer as short and open as it used to be. The vegetation tends to be even longer and more closed further into the fell, suggesting that the sheep have not been visiting these areas as frequently as the areas closer to the track.

We are working with Natural England on various options for adressing this, including remedial restoration work (by cutting) in some areas and re-considering the optimum numbers of sheep to have on the fell. Our data is very useful for informing these decisions.

Before doing this comparison of the two survey results, I was aware that some of the special plants had probably declined and that the habitats supporting them was probably sub-optimal now in many places. But I was genuinely shocked and saddened by just how much these species had declined and by the fact that all of them had declined.

As if this was not bad enough, the special species are also declining in population size in the places that they still grow in. The results described above only tell us about changes in extent, in other words, changes in areas occupied by the plants. A dot on the map could mean that 1 plant was present, or that many hundreds of plants were present.

Species	1968-1977	2002-2010	% decline
Draba incana	451	1	100%
Polygala amarella	531	13	98%
Viola rupestris	976	406	58%
Primula farinosa	665	376	43%
Carex ericetorum	61	43	30%
Average (mean) decline			66%

Changes in population sizes in monitoring plots

The table above shows the results from two other surveys that counted numbers of plants in permanently-marked monitoring plots. These plots were set up by Margaret in 1968 and plant numbers were counted by her and volunteers every year from 1968 to 1977. This same survey was then repeated each year from 2002 to 2010. All five species showed substantial declines in population size. On average, the number of plants of these special species declined by two-thirds in the thirty years or so between the two survey periods.

The number of dwarf milkwort plants declined by 98% between the two surveys

These depressing results suggest that the special flora of Upper Teesdale has not been receiving enough attention for a while. Results like these from detailed surveys with sound methodologies give us strong evidence to back up what Margaret has been saying for many years about the general decline in the Teesdale flora.

Parasitic plants in Teesdale

While doing a session on eyebrights in Widdybank Meadows with Margaret’s botany group on monday, we were pleased to see semi-parasitic plants from four different genera (Euphrasia, Rhinanthus, Pedicularis and Bartsia) in the very species-rich flush in one of the meadows.

Marsh lousewort Pedicularis palustris always grows in good quality wet habitats, so when you spot it, there is always a good chance that you will find other interesting plants with it.

The picture below is of the common subspecies of yellow rattle Rhinanthus minor subsp. minor, but at Widdybank Meadows, we also get the much rarer upland subspecies monticola, with tapering leaves and a brownish flower.

We get six species of eyebright in Teesdale: E. arctica, E. confusa, E. nemorosa, E. scottica, E. micrantha and E. officinalis subsp. monticola. And, of course we probably get just about every possible hybrid combination between this set of species. In our flush, the eyebright looked a bit like Scottish eyebright E. scottica, as you would expect in that habitat, but it had largish flowers with a long lower lip and leaves that were not as narrow as you would expect typical E. scottica leaves should be. My guess was that it may have been the hybrid between E. scottica and arctic eyebright E. arctica, which is abundant in the adjacent meadow vegetation.

The photo above is of montane eyebright E. officinalis subsp. monticola. This is one of our special rare plants and one of my favourites. It only grows in species-rich upland hay meadow vegetation and mostly in the rarest form of damp upland hay meadow vegetation (M26b in the NVC classification). It is a Nationally Scarce species and listed as Vulnerable on the UK Red List. There was a small population of it in one of the other meadows at Widdybank Farm on monday night.

alpine bartsia (photo by Margaret Bradshaw)

The fourth semi-parastic plant we saw in the flush was alpine bartsia Bartsia alpina, which was looking really good and even had flowers! This is another of the Teesdale special plants. It is Nationally Rare, with it’s main British distribution in the Breadalbanes in Scotland. It is very rare in England and is listed as Vulnerable on the England Red List.

Species in all of these genera are considered semi-parasitic, because they are parasitic on the roots of other species, but they also have chlorophyll, so they don’t rely totally on their host plants. Broomrapes Orbanche and Parentuciellia species, and toothworts Lathraea species, are totally parastic and have no green parts. In Teesdale I don’t think we have any records of broomrapes, but we do have a few for toothwort Lathraea squamaria.

Both the semi-parasitic and totally parasitic genera are now in their own family Orobanchaceae, following recent DNA work. Before, the semi-parasitic genera were included in a very variable Scropulariaceae family. The other genera that were included in Scropulariaceae in the past have been further split into a much smaller Scrophulariaceae (which now includes genera like Scrophularia, Verbascum, and bizarrely, Buddleja), the new family Veronicacea (including genera like Veronica, Digitalis, Cymbalaria, Kickxia, Linaria and Erinus) and several other new families, none of which include any native British species. This new arrangement seems to make sense. This is reassuring, as keeping up with taxonomic changes can be annoying and might seem pointless, but changes like this seem worthwhile.

The new Orobanchaceae family includes several other geenra of semi-parasitic plants. In Teesdale we have a few records for red bartsia Odontites vernus, but it is much more common in the lowlands.

We get quite a bit of common cow-wheat Melampyrum pratense in the more wooded parts of the Tees riverbank. There are old records for the much rarer small cow-wheat Melampyrum sylvaticum from a few places places along the Tees, but the most recent record we have is from 1976. We would love to find some of this again. It is one of those species that is often recorded in error, as less experienced botanists sometimes assume they have found it when they find small plants of common cow-wheat. Unfortunately, it is not that simple!

Also, one of the characters given for identifying it is difficult to interpret. For M. sylvaticum, the lower lip of the corolla should be strongly reflexed, while in M. pratense it is ‘not reflexed’, with it’s underside forming a straight line with the corolla tube. However, in the photo above, you could be tempted to go for a reflexed lower lip, as a small portion of the end of the lower lip is clearly reflexed. But the whole lower lip needs to be turned down and not forming a straight line with the corolla tube.

A less confusing character for separating them is in the calyx. If you look at the calyx of the lower of the two flowers in the middle of the photo above, you can see that the lower two calyx teeth are appressed to the corolla tube. In M. sylvaticum these would be patent, i.e. sticking out at right angles.

Small cow-wheat is Nationally Scarce (and very close to being Nationally Rare), with all of it’s more recent British records from Scotland. It is listed as Regionally Extinct on the England Red List. Please look out for this species if you are walking along the Tees riverbank! And don’t forget to let us know if you find it!

The joy of sedge

Sedges are one of my favourite groups of plants. They are not showy. They are difficult to identify when you are first starting off, as you often have to look carefully at small features on their flowering/fruiting parts, which may vary only subtly from each other. But this encourages you to look closely at things you would otherwise not see, opening up a new world of unique structures and their associated jargon, such as ‘utricle’ and ‘glume’. I find it satisfying to identify groups of plants that take a bit of time and effort to get to grips with.

They also make attractive specimens when you dry and press them. Unlike many plants with colourful petals, dried sedges look similar to fresh specimens, so they turn out to be useful for identifying other plants in the future. And many of them are small enough to fit quite easily onto an A4 sheet of paper.

spring-sedge Carex caryophyllea *in flower*

The photo of spring-sedge in flower above shows the cream-coloured anthers on the male spike at the top of the plant, with the white stigmas on the lower female spikes. The pictures in many identification books show very broad, club-shaped male spikes, but they only occasionally look as broad as in those pictures. This is a common species but tends to only grow in fairly species-rich, infertile grassland habitats. The green male glumes (scales) on the male spikes with a brown border, help distinguish it from ‘rare spring-sedge’ Carex ericetorum, which has chestnut-brown glumes, with a very pale border.

Rare spring-sedge is one of the special plants in the Teesdale assemblage. A unique feature of the Teesdale assemblage is that it includes ‘southern’ plants as well as northern arctic-alpine species. Rare spring-sedge is one of the rare, southern plants that have their most northerly British populations in Teesdale.

long-stalked yellow-sedge Carex lepidocarpa

The (badly focussed) shot of long-stalked yellow-sedge above was from a pool in Middleton quarry. It’s normal habitat is species-rich calcareous flushes, where you often find other interesting plants, so it is always a good one to find. Each flowering/fruiting stem has several yellowy-green female spikes, which are quite fat and spiky, with one narrow, pale brown male spike on a stalk at the top. Not all sedges have separate male and female spikes like these, or even separate male and female flowers.

The flowers of flat sedge are all bisexual. The genus Carex is the by far the largest sedge genus in Britain, but we have at least 13 other genera from the sedge family. All other British sedge genera apart from Carex have bisexual flowers. Flat sedge is uncommon in Britain and has declined massively in recent decades, so that it is now regarded as a threatened species. The ‘flat’ part of the name refers to the inflorescence being more-or-less flattened in one plane, which isn’t obvious from the picture below, but is obvious when you see it.

We still have some large populations of flat sedge in here and there in Teesdale. One of it’s favourite habitats is alongside upland rivers and streams, in species-rich grassland that is flooded regularly when the river is in spate.

A superficially similar-looking species is false sedge (below), but its inflorescence is not flattened in one plane. It has separate male and female flowers, but they are mixed together in the same spikes.

The ‘false’ part of the name comes from the fact, that previously, it was regarded as being closely related to the genus Carex, but not quite close enough to be included. It differs from other Carex species in having an open utricle (covering around the nut). Its old scientific name was Kobresia simpliciuscula and as it was the only species in that genus, people tended to refer to it just as ‘Kobresia‘. Following recent DNA work, it has now been included in Carex, so we can no longer validly call it Kobresia. That is annoying, as I don’t find it easy to pronounce the species name ‘simpliciuscula‘.

False sedge has a much smaller national distribution than flat sedge. Its main British distribution is in the highlands of Perthshire and Argyll and the only other British populations are in Teesdale. In the right habitats in some parts of Teesdale it is super-abundant. There must be many millions of plants here, making it the most abundant of our special plants.

Not many of the other really special plants of Teesdale are sedges. We do have big populations of hair sedge Carex capillaris, which is mainly a plant of the Scottish Highlands, but occurs in a few other places in northern England and north Wales.

Maybe the most interesting sedge we have is sheathed sedge Carex vaginata. This is another species mainly of the Scottish Highlands in Britain and was discovered new to England in 2002 when the Foot-and-Mouth epidemic meant that many areas of the high fells were left ungrazed for a year. Sheathed sedge was found flowering on Dufton Fell by Rod Corner that year and once local botanists got to know it (particularly its vegetative features), they found several more populations in the higher parts of the North Pennines. Since 2002 however, it has not been common to find it flowering again. It seems to be able to persist vegetatively without reproducing for long periods.

BSBI meeting 2019

We had a very nice group and great weather for our BSBI meeting on 11th and 12th May. The first group of plants we looked at were Lady’s-mantles, in the road verge by Langdon Beck Hotel. Two of the rare species, Alchemilla acutiloba and Alchemilla monticola were growing there. Both are very rare nationally. Alchemilla monticola is quite widespread in Teesdale. Alchemilla acutiloba is much more localised in Teesdale, but is common in Weardale, which is the next valley to the north.

Margaret enjoying teaching us about Lady’s-mantles

Margaret has been the national expert in this group of plants for many years, so it was great to have her show us the key differences between the different species. In the 1950s, she found Alchemilla subcrenata new to Britain in Teesdale. Apart from very localised populations in Weardale and Allendale, the main population is confined to a few fields and road verges in a small part of Teesdale around Newbiggin and Holwick.

A young Lady’s-mantle leaf looking very like Alchemilla subcrenata

On the second day of our meeting, Laura noticed a young Lady’s-mantle that looked a bit different and initially we thought there was a good chance that it was Alchemilla subcrenata. Good features for this species are the (few) large teeth on the leaf margins and the upturned basal leaf lobes. This would have been the best find of the weekend, as the place where we found it was about five miles from the main population further down the valley. Margaret reserved final judgement until the plant grew a bit bigger. When we went back to check three weeks later, all of the plants in that area were looking much more like typical Alchemilla monticola. A tricky group!

On our field meeting, most of the rare plants that flower early were showing well, including spring gentians and bird’s-eye primrose.

We were lucky that there were plants of both Teesdale violet and it’s hybrid with common dog-violet in flower, so that we could compare them closely. The flowers of these violets do not tend to last long. I suspect that the sheep find them tasty. Fortunately (for botanical recorders!) the leaves of Teesdale violet are quite distinctive looking. The basal lobes do not curl fowards like in most other violet species, giving the leaf a more ‘shovel-like’ appearance. The leaves of the hybrid are much closer in shape to common dog-violet leaves.

Viola x burnatii – the hybrid between Tee4sdale violet and common dog-violet

Hello!

This blog aims to encourage more interest in the special flora of Upper Teesdale. It is part of Margaret Bradshaw’s Upper Teesdale Special Flora Recording and Conservation project.

meb and queenie

Margaret has worked on the rare and special plants of Upper Teesdale since the early 1950s. Three years ago she decided to use her own money to set up a project aimed at stimulating more interest in the Teesdale flora. The main focus of the project is on recording the rare plants in more detail than before. This should help with efforts to conserve the species and habitats in future, as it will give us a better idea of just where everything is and which areas are particularly important.

margaret and me

I feel very privileged that Margaret choose me (John O’Reilly) to be the main botanist doing the recording. It is great to get to work with so many rare plants and in such an amazing place. If someone had told me ten years ago that I would be doing this job now, I wouldn’t have believed them. I can’t imagine that there is any better job for a botanist in Britain than this one!