Common Whitlowgrass Re-visited

OK, so I've discussed this already - but I went back to the site (the concrete 'raft' on the river bank) a couple of days ago and was amazed by how many more plants had come into flower. Not only that but, in the bright sunshine, all of the flowers were fully open and displaying their characterstic, deeply-notched petals.

It may be my imagination but the plants also seemed to have a 'scent' - and not a very pleasant one. As I got down close to these tiny plants, in order to photograph them (again), I became aware of a faint odour - a bit like acrid, sweaty feet (I'm fairly certain that it wasn't anything to do with my feet!). I've forgotten a lot of my chemistry but I think that the smell may have been characteristic of certain fatty acids (Palmitic or Oleic ... possibly?). Anyway, it's probably a good thing that the plants aren't any bigger or everyone would be complaining about the pong!

Dave Bishop, March 2009

The Spring Crocus

In my article on the Autumn Crocus (1) I related how, in the Middle Ages, the Knights of St. John of Jerusalem acquired land in the Southern Pennines. They grew the South Western European species Crocus nudiflorus as a source of saffron which they valued for its medicinal properties. Because I had not seen any evidence for the presence of the Knights of St. John in the Mersey Valley I have always assumed that our Crocus plants were washed down the Pennine watershed in winter floods, and I still think that that is the most likely origin of many of our colonies.
Nevertheless, an article which appeared in a natural history magazine several years ago added a new twist to the story. The article (2) was written by Steve Alton, a Nottinghamshire Conservation Officer. Mr Alton related how C. nudiflorus was once common in the flood meadows of the River Trent near the city of Nottingham but in that location it was usually accompanied by the Spring Crocus (Crocus vernus). It should be noted, of course, that the two species don’t actually flower together but in the spring C. vernus produces both flowers and leaves whilst in the case of C. nudiflorus only the distinctive leaves are visible at that time. In his article Mr Alton states that the Spring Crocus in the Nottingham area appeared to have spread out from Lenton Priory, which was owned not by the Knights of St. John but by monks of the Cluniac order. The priory was founded between 1108 and 1114 by William Peverel, son of William the Conqueror. This order originated in Cluny, in Burgundy (South Western France) where both the Spring and Autumn Crocuses grow wild. In addition it appears that the monks owned two hermitages – one in caves near the priory and the other across the Pennines at Kersall in Salford. This is almost certainly a reference to Kersall Cell in the Irwell Valley. Apparently there was a well-used road between the priory and Kersall and there are nine Autumn Crocus sites along its route.
After reading the article cited above it occurred to me to start looking for Spring Crocuses in the Mersey Valley and, in particular to look for sites where both species grow together.

Before I discuss my findings further I need to describe the Spring species in a bit more detail:
Crocus vernus is a central European species found from the Pyrenees to the Carpathians. It is a mountain plant found around snow patches and in mountain meadows and sub-alpine woods. It is taxonomically quite complex with many variants and at least two subspecies (3). Flowers colours range from purple through lilac to pure white; some plants are purple with white stripes. A major problem with looking for colonies which might be old is the fact that this species is still being planted as an ornamental and such planting could have occurred any time in the last century or so. Nevertheless, modern cultivars tend to be larger than the wild types and they are often planted with a yellow species (usually the hybrid Crocus x stellaris).
In Nottingham two of the areas where both Crocus species have lingered on are in churchyards and cemeteries, so I made a point of looking in Mersey Valley churchyards and cemeteries. My findings are as follows:

Heaton Mersey

There is a colony of Spring Crocuses in an overgrown site off Vale Road opposite an industrial estate. I’m not sure what the history of this site is except that there were bleach works in this area (hardly relevant, one would think, in this context). When I first found this site in the mid 1990s the plant colonies were clearly visible at the bases of some old gate posts but when Priscilla Tolfree and I visited it again a couple of years ago the plants were just holding their own against a sea of invading Ivy.

St. James Churchyard and Fletcher Moss Gardens, Didsbury

Apparently both the church and the churchyard have been much altered during the last few centuries (4) but there are a small handful of Spring Crocuses to be found in the upper part of the churchyard closest to the church. At the western end of the yard, furthest from the church, and at a lower elevation, there are some groups with the large cultivars and the yellow flowered hybrid, characteristic of modern plantings, referred to above.
On the lawn in front of the Old Parsonage nearby there is a large drift of Spring Crocuses of the ‘wild’ type – could these have been moved there during one of the periods when the churchyard was being altered? I suppose that this is possible but it must remain pure speculation.

Ford Lane and St. Wilfrid’s Churchyard, Northenden

Northenden is a ‘Crocus Hotspot’! The bank on the south side of Ford Lane (the opposite side from the river), near Didsbury Golf Course, is a good site for C. nudiflorus and slightly further on, around a gate leading on to the Golf Course, is a magnificent display of C. vernus (see top photograph above). These two populations do overlap slightly and are the best example that I know of the two species growing together in this area.
St. Wilfrid’s churchyard, in Northenden itself, has a huge population of C. vernus. I visited this churchyard most recently on Friday 6th March, 2009 and was greatly impressed by the magnificent and very beautiful drifts of this species. Equally impressive was the fact that, even this early in the spring, the flowers were being visited by a huge swarm of honey bees. Also present in the same churchyard was another species, C. tommasinianus (5). I suspect that some of the flowers that I saw were, in fact, hybrids between the two species. This is worrying because, in time, there is a chance that the C. vernus plants could be ‘hybridised-out’.

Southern Cemetery, Chorlton

This cemetery is rich in spring bulbs, particularly the north eastern boundary, adjacent to Nell Lane. There is little doubt that most of these have been planted fairly recently, by the local authorities, but there are drifts of C. vernus which I suspect may be older. There is certainly evidence that a substantial population of C. vernus was present in this area in the mid 19th century because the botanist Leo Grindon recorded such a population from “... a meadow opposite the gable of Hough End Hall” (6). I think that there is a very good chance that the Southern Cemetery plants are the remains of the same population. Again there is worrying evidence that these historic plants are being ‘hybridised-out’ by C. tommasinianus.

St. Michael’s Churchyard, Flixton

There is another population of C. vernus in this churchyard and Priscilla Tolfree found C. nudiflorus on the golf course nearby.

So, what are we to conclude? Frankly, it’s very difficult to know. The situation is like a giant jigsaw puzzle with many lost pieces. There may well have been (at least) two religious/monastic orders locally, who, between them, introduced two Crocus species into the Manchester area, almost certainly as a source of saffron. It will take a far, far better historian than me to sort it out! Nevertheless, I feel that these plants have great significance both in terms of local biodiversity and local history and heritage.

Dave Bishop, March 2009

References:

1. ‘The Autumn Crocus’ - FoCM Blog, Saturday 20th September, 2008

2. ‘Crocus Connections’ by Steve Alton, ‘Natural World’ No. 38, Autumn 1993

3. ‘The Genus Crocus’ by Brian Mathew, Batsford, 1982

4. ‘A History of Didsbury’ by Ivor R. Million, Didsbury Civic Society & E.J. Morten, 1969

5. ‘The Early Spring Crocus’ – FoCM Blog, Saturday 21st February, 2009

6. ‘The Manchester Flora’ by Leo H. Grindon, William White, 1859

A Glimpse of the Mersey Valley 50 Years Ago Today

A couple of years ago Phil Robinson, of Chorlton Civic Society, knowing of my interest in the Mersey Valley, passed on to me a black, loose-leaved folder which he had found among the archives of the Civic Society. The folder contained details of a study performed 50 years ago by a local lady named Hilda F. Broady. Mrs Broady had chosen a small area (which she refers to as, “the plot”), in what she called “Chorlton Meadows”, and studied the wildlife of that spot at regular intervals over the course of the year 1959. The spot that she chose was not technically in the Meadows but was in ‘Barlow Wood’, the site of an ancient wood above the Mersey floodplain. Barlow Wood is now off limits to the public because it is within the boundaries of Chorlton Golf Course. The study gives an interesting insight into which plants and other wildlife were present 50 years ago and I have decided post it (in instalments) on the Friends of Chorlton Meadows blog because of its intrinsic interest and because I think that it should be better known. I will post each instalment on the days corresponding to those on which Mrs Broady surveyed her plot in 1959.
Some local Chorlton people have told me that they remember Mrs Broady and it is likely that she was a school teacher who probably lived in Chorltonville. There is always the possibility that some people, including Mrs Broady’s surviving relatives, may object to this work being published on the FoCM blog and if so they should contact me and, if necessary, I will gladly delete it. Nevertheless, they should know that I post it in the spirit of greatest respect for Mrs Broady, her work and her curiosity, and for the fact that she obviously loved the Mersey Valley and its wildlife as much as I do. I sincerely hope that she would approve.

Mrs Broady’s journal commences with a section entitled, “Some Interesting Historical Facts About The Site Of The Plot”

The hamlet of Hardy consisted of groups of cottages between Hardy Farm and Jackson’s Boat, the last of which were taken down shortly after the flood of 1854 [this date is indistinct in the original typescript and could be ‘1954’ – must check - ed.] when Chorlton Meadows were flooded to a depth of about three feet.
According to Whittaker, the word “Hardy” is derived from the name of that ancient Forest of Arden, but as the settlers in Manchester cleared away the woods, detached patches of the thicket were left standing here and there. One of these skirted the Mersey in this district, hence the name “Hardie.”
Barlow Wood is the only remains of the ancient Forest of Arden left standing in the district. The tract of low lying land behind Barlow Hall up to Jackson’s Boat is known by the name of Barlow Leys, which was formerly of a marshy character, and used by the farmers of the village as a ley for their cattle, but about 1822 it was drained and placed under cultivation. Barlow Hall stands on the top of a series of slopes stretching to the river.
Mr. Thomas Ellwood traced the history of the township from the year 610, when it became colonised by the Saxons, “who disencumbered the land of its ancient oaks,” to the present time (1922) remarking that in the spring time of 1865, when he first came to Chorlton, the acres of orchards in bloom made it one of the prettiest villages he had seen.
Barlow Wood is now skirted on one side by the golf links, and on another side by Council house property.

The Journal

8th March 1959

After surveying Chorlton Meadows, a plot was chosen in a spot known as “Barlow Wood”.
It was a bitterly cold day, and the ground was very cold and dry. The grass, which was short and only a few inches high, appeared parched. I tried to uproot some plants but the ground was too hard to manage without digging tools.
There is a tree in bud on the plot, and another half-dead tree. There are a number a number of similar woody shoots which I cannot yet name. There is the bed of a stream, which is completely dry and the ground hard.
Shoots identified as Sycamore – Acer Pseudoplatanus.

For comparison, the weather on the on the 8th March 2009 was cool, windy and overcast by mid-day. Around lunchtime there was a heavy shower and around 2:30 pm there was a brief hailstorm .
The above was obviously just a preliminary survey and Mrs Broady next surveyed her plot on the 1st April 1959 and I will try to post the next instalment on the 1st April 2009 – ed.

Posted by Dave Bishop, 8th March 2009

Wind Pollination

Many flowering plants are insect pollinated. The flowers attract insects through visual cues, scent and nectar. Once attracted the insect picks up sticky pollen grains from the flower’s stamens (the male parts of the flower). On visiting a second flower the pollen grains are deposited on the stigma (the female part of the flower) and, hence, the flower is ‘pollinated’ (i.e. fertilised). Subsequently fruits and seeds develop.
Some plants, though, are wind pollinated. Most British tree species are wind pollinated, as are grass species and some species of flowering herb. Many wind pollinated tree species produce ‘catkins’ which are long, dangling, pollen-bearing ‘tassels’. The catkins are composed of many scale-like structures between which are the stamens. Once the catkin is fully extended it dangles in the wind, the scales open and the pollen is displaced from between them by air currents. Some of this air-borne pollen eventually encounters a female flower, which is equipped with stigmas, and pollination occurs. These female flowers are usually carried on the same tree but separately from the male catkins.
Wind pollination is immensely ‘inefficient’ in terms of pollen production. Huge amounts of pollen is produced, much of which is wasted because it fails to encounter a receptive stigma. It has been estimated that a single Hazel catkin produces nearly four million pollen grains. Pollen grains from wind pollinated plants are, proportionally, much smaller than those produced by insect pollinated plants and they tend to be smooth rather than sticky. Subtle mechanisms are in place to avoid auto-fertilisation (there is more information on this in the references).
Many wind pollinated trees produce their catkins early in the year before the trees’ leaves appear. This avoids the possibility of leaf surfaces trapping, or impeding the progress of, pollen grains through the air.
In late February to mid March two excellent examples of wind pollinated trees in the Mersey Valley are Hazel (Corylus avellana) and Common Alder (Alnus glutinosa). The top photograph shows seven Hazel catkins. The female flowers are tiny, scarlet brush-like structures and there is one near the top right of the photograph and another near the extreme left. Once pollinated these gradually develop into Hazel nuts.
The bottom photograph shows Alder catkins. This time the female flowers are small, red, bristly ovoid structures near the centre of the photograph. Once fertilised these develop into small, woody ‘cones’ (rather like miniature fir cones). Last year’s cones are still present and are visible near the top right of the photograph.
The most ‘historic’ Hazels in this area are probably those along Hawthorn Lane (the old border between Chorlton and Stretford). These have been grievously ‘hacked about’, in recent years, by the local authorities (who probably don’t know what they are, don’t understand their significance and probably wouldn’t care if they did!).
Some of the finest Alders are on the little triangle of land formed where Chorlton Brook flows into the Mersey. I am convinced that these are self-seeded. This is a reminder that Alders tend to be found along water courses because the seeds are water-proof and buoyant and float down-stream until they lodge in the bank. Alders can happily grow in water-logged ground and have nitrogen-fixing nodules on their roots. If you take a train journey, at this time of year, look out for a sort of ‘reddish haze’ above water courses - the effect of millions of Alder catkins and female flowers.

Dave Bishop, March 2009.

References:

1. ‘The Pollination of Flowers’ by Michael Proctor & Peter Yeo, Collins 1973

2. ‘The Biology of Flowers’ by Eigil Holm & Thomas Bredsdorff, Penguin 1979

3. ‘How Flowers Work’ by Bob Gibbons, Blandford Press 1984

Common Whitlowgrass

Here's a very early spring flower which you would be forgiven for not noticing. This is because it is only a few cm high and easily overlooked.

Common Whitlowgrass (Erophila verna) is not a 'grass' at all but a member of the Cabbage Family (Brassicaceae); I'm not sure what it has to do with 'whitlows' - it was probably used to cure them at one time.

It is a plant of old walls and rocky places. I look for it every year in a rather unusual site - on the river bank, adjacent to Chorlton Ees, about 1/4 of a mile east of where Chorlton Brook flows into the Mersey. Here there is a small weir in the river and the banks on either side are strengthened with concrete 'rafts'. Each raft is like a small rock garden with Mosses, Stonecrops, Geraniums, Vetches and other plants including the Whitlowgrass.

The plant consists of a rosette of leaves with the flower bearing stalks emerging from the centre of the rosette. Plants with rosettes like this are often adapted for dry conditions (it is a common form adopted by Alpine species). No doubt the Whitlowgrass has to endure drought conditions but, ironically, it is also periodically inundated when the river is high! The flowers have four, deeply notched, petals which are not easy to see in the photograph above (they appear to need bright sunlight in order to fully open - and there hasn't been a lot of that lately - at least when I've been trying to take photographs of E. verna!).

Dave Bishop, March 2009

An Additional Training Course

Dear Friends,

Please note an additional course that you are invited to participate in:

'Grassland Monitoring Methodology' run by Rob O'Connor (grassland ecologist).

Date: 25th April 2009

Time: 10:00 am to 4:00 pm

Venue: Mersey Valley Visitors' Centre, Rifle Road, Sale (near Sale Water Park).

As before this course is free for all members of the Friends groups.

This will be another important course for us. There are several areas of derelict, or semi-derelict, grassland in Chorlton Meadows (a 'Meadow' is, after all, grassland by definition!). Our aim is to attempt to restore some of these areas and to do this properly we need to record what species are there now and to monitor changes that occur as we institute management regimes.

Alex Krause has asked me to point out that two of the courses that she has arranged for us are currently under-subscribed. These are:

Peter Hardy's Butterfly Monitoring Course (28th and 29th March)

and

Liz Blackman's Wild Flower ID course (13th June).

So don't miss out and sign up with Alex asap! Please see the previously published programme for full details.

Alex Krause's phone number is: 0161 881 5639

Her email is: a.krause@manchester.gov.uk

Holly - A Slow and Stealthy Invasion?

A couple of Christmases ago I had to smile at an article that I read in a newspaper claiming that there was a shortage of Holly. There's certainly no shortage in the Mersey Valley - Holly seedlings are everywhere! Has anyone else noticed?

Holly (Ilex aquifolium) is a native tree. It is a 'dioecious' species which means that male and female flowers occur on different plants. This means, of course, that the familiar red berries only occur on female trees. It is also quite slow growing and the females don't start producing berries until they are around 20 years old. Holly is also semi-evergreen and retains many of its leaves throughout the winter.

In 'Flora Britannica' Richard Mabey tells us that Holly was (and occasionally still is) fed to livestock. In spite of its prickly leaves they, "...have one of the highest calorific values of any tree browsed by animals, and are rich in nutrients." Oliver Rackham has described Holly leaves as, "iron rations for sheep". Mabey also quotes the findings of a researcher called Martin Spray who found that the use of Holly as cattle food, "was a widespread, if not always well-documented practice up until the eighteenth century. [And] it seems to have been particularly prominent on the grits and sandstones of the Pennine foothills, roughly in the triangle formed by Derby, Leeds and Manchester." Spray also found many 'holly' and 'hollin' place names, and even surnames, in this area.

I don't really know what the Holly invasion means, but could it be that the old countryside is, in a sense, re-asserting itself? If so, there are few animals around to browse on it and in a hundred years time (if there's anything left of the Mersey Valley by then) local people could find themselves living in the midst of a vast, gloomy Holly wood ...

Incidentally, another evergreen species is beginning to appear as well. I estimate that for every 20 or 30 Holly seedlings there is a Yew (Taxus baccata) seedling - and I haven't got the faintset clue what that means!

Dave Bishop, February 2009

References

'Flora Britannica' by Richard Mabey, Sinclair-Stevenson, 1996

'Woodlands' by Oliver Rackham, Collins, 2006