Ptyxis Ecology - Our Botany Blog

Sunday, 17 July 2011

Chickweed willowherb in south Northumberland

Chickweed willowherb Epilobium alsinifolium is one of our montane willowherbs that is scattered in the North pennines, the Lake District, The Cheviots, the southern Scittish uplands and North Wales, as well of course as the Scottish Highlands. See the distribution map from the BSBI website at http://www.bsbimaps.org.uk/atlas/map_page.php?spid=690.0&sppname=Epilobium alsinifolium&commname=Chickweed Willowherb

Our county recorder John Richards (who is also an expert on alpine plants), took this photo recently at the only site for this plant in south Northumberland.
John says that out of 500 plants present in the flush this was the only one that was flowering! So it would be easy to overlook it if you were not an expert. The previous county recorder George Swam found the plant at this site in 1969 and last recorded it there in 1991. John was revisiting the site to check out the population as part of a series of surveys he and others are doing to check on populations of Northumberland's most rare and special plants.

You can see an account of all of the county's rare plants at http://botanicalkeys.co.uk/northumbria/rpr.asp

John

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Its all gone yellow!

Many traditional arable weeds have declined hugely or dissappeared completely due to changes in agricultural methods in the last 60 years. Corn marigold still survives here and there, but is much, much less common than it was.

It is very rare now to see so many corn marigolds in an arable field like in this picure from Bamburgh. There is an interesting story behind this. Steve Pullan sent me these pictures and explained what happened. Steve and I used to work together at RDS setting up agri-environment schemes and Steve still does this work for Natural England. These fields have been in arable for a long time, but for the last 4 years they have been managed organically, which has allowed some corn marigolds to germinate from the seedbank and grow in the crop. You can see quite a few corn marigolds in the foreground, but there is a continuous sea of deep yellow in the background.

This field has some interesting archaeology below the ground and so the field is in the process of being converted from arable to grassland to protect the archaeology. A grass and clover mix has been sown and the cultivation method encouraged the corn marigolds to germinate. There must have been many thousands of corn marigold seeds in the soil for years waiting for their opportunity. Of course, as the field will be a grassland in future, the corn marigolds are likely to dissappear in a few years once the sward closes up. But there will be lots of seeds produced this year that will lie in the soil waiting for the soil to be disturbed again.

In the latest edition of Stace's flora from last year, several common plants have been given new scientific names. We now have to call corn marigold Glebionis segetum which sounds very odd when you are used to the old name Chrysanthemum segetum. I guess we will have to get used to it, but you see the plant so rarely nowadays that there is lots of time to forget the new name before you see it again.

John

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Saturday, 9 July 2011

A long week’s botanising in South Northumberland

It is always a great pleasure to visit Northumberland. Compared to the suburbs of Brussels, it is quiet, friendly and interesting. After a year since my last proper recording trip any small glimpse of wild places is a pleasant experience and Northumberland always has a few botanical surprises in store for me. So, I thought I’d share my finds in the hope that someone finds them interesting.

I started off my trip around Blyth and Ashington. It is not the most obvious location for botany, but random squares settle where they will. Still, this small area contains the only salt marshes and some of the best lowland ponds in the vice county. horned pondweed (Zannichellia palustris) was my favourite find in this area. It is not common, though it may be more common than records suggest. It lurks, cryptically, under water often in the shade of bigger, more obvious water plants.

Moving on, I passed by Heighley Gate Garden Centre. I was not there to buy plants, but to see if they had been infected. New Zealand bitter-cress (Cardamine corymbosa) has been rapidly spreading across Europe like a disease of pot plants. It didn’t take long to find it there. By the way, this bittercress should not be confused with either wavy bitter-cress (Cardamine flexuosa) or hairy bitter-cress (Cardamine hirsuta), which also inhabit plant pots at garden centres. Another treat of Heighley Gate, was seeing their Mistletoe; to my knowledge, this is the only Mistletoe in Northumberland. Though it is obviously introduced, it is interesting that it flourishes so well, even though it fails to naturalise.

Further north I had a long visit to Holystone where I recorded about 220 species in one monad! This small area contains all sorts of little habitats, including river bank, bog, moor, meadow and woodland. Probably the best find was one plant of hairy rock-cress (Arabis hirsuta) on the shingles of the Coquet. It has been recorded in that area previously and I hope that this one plant might be an outlier from a larger population upstream.


The habitat of Arabis hirsuta on the Coquet gravels

On the Sunday, John O’Reilly, Phil Brown and I went to look at Hummell Knowe and cover the neighbouring monads. Phil managed to collect and then get refereed Trichophorum x foersteri; T. cespitosum and T. germanicum all from Hummell Knowe. Even though the neighbouring Burndivot monad looked rather boring, we still managed to find 141 species in it.

During the visit I interspersed trips to wild places with “boring” agricultural monads. One of the big surprises from these “boring” places was great brome (Anisantha diandra). I found it for the first time last year, near Newcastle Station. I had assumed it was a casual there. Still, this year I found it at five new sites, four of them inside random monads. It has obviously increased in the county, but it has perhaps also been mistaken for barren brome (Anisantha sterilis). You may find it in the borders of wheat and barley fields where both Anisantha species can be found growing together.

The rarest record was refinding needle spike-rush (Eleocharis acicularis) at Catcleugh reservoir. I found one patch of less than 1m2. To my knowledge it was last seen there in 1972. I think the low water helped to make it more visible.


The view of one monad, Lumsdon Law from another, Hungry Law. near Catcleugh

In the last couple of days I revisted the Bee Orchids at the Royal Keys. The old sewage works is perhaps the best brown-field site in Northumberland. It hasn’t been surveyed thoroughly but contains at least 200 species including musk thistle, yellow-sedge, delicate stonewort and even common cottongrass, which is practically extinct in the south-east of the county.

Last, but not least, I found a small patch of grass vetchling (Lathyrus nissolia) in a monad near Amble. It is an elegant plant, which is practically invisible amongst grass, were it not for it flowers. It has been moving northward in the country, perhaps as a contaminant of grass seed.

Well, it isn’t easy fitting a year’s worth of recording into a long week but I did my best. I will now look forward to next year and ponder over what I might find then.

Quentin Groom

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Sunday, 28 November 2010

Schedule 9 invasive plant identifcation course

And now there are 40!

Until April 2010, there were only 2 non-native invasive plant species that ecologists doing site surveys for developers really had to worry about finding - Japanese knotweed and giant hogweed. But now 38 species have been added to schedule 9 of the Wildlife and Countryside Act 1981, for which it is a criminal offence to cause to grow in the wild.

Many are rare and easy enough to recognise, but a few are widespread and tricky plants to identify. I have been persuaded to run an id- course on the whole lot, in one day. This is ambitious! But I think it is needed. Ecologists are the professionals that clients will rely on to survey for these plants - and unless you want to bring in an experienced botanist on every Phase 1 survey, you need to at least know what to look out for.

See www.ptyxis.com for details (on a downloadable flyer on our front page news section) ; or email me clare@ptyxis.com

Grass Identification Course makeover!



Get Going with Grasses!


I have taught grass identification and ecology for 8 years now, and each year I keep on discovering better ways to help ecologists learn about the green stuff!

The main problem is botanical keys : none are aimed at beginners or non-specialists, plus keying out can be tedious and time-consuming. But then recognsing species by jizz and learning by rote on a guided walk-and-talk doesn't really do the job either - you need a tool to enable you to identify unknown grasses on your own.

So for 2011 I have written an innovative, comprehensive vegetative key to British native grasses and all the widespread non-natives that you are likely to come across. This key is unlike anything else out there, as it bridges the gap between the academic floras and picture books. I plan to publish it eventually, but until then you can get a copy and learn how to use it on one of my grass courses.

Why vegetative grasses? Well, this is by far the easiest place to start grass identification, as the parts of the plant are easy to see; grass flowers are made up of tiny scales that you cannot really see, count or measure without magnification - and measuring their bits is really too fiddly in the field!

Botanists rarely use keys to identify grasses during site surveys - mostly we use a combination of both vegetative characters and features of the flower, keying out as it were, in our heads. You can learn to do this too!!

Course details are on my website www.ptyxis.com/training.html or email me clare@ptyxis.com

Clare

Sunday, 31 October 2010

Looking for a plant identification, botany or habitat survey training course?

We are running a programme of plant identification courses aimed at professional ecologists and interested volunteers again in 2011. See www.ptyxis.com/training.html or email us on enquiries@ptyxis.com for a Booking Form & prices. Our courses are the same price as most ecology CPD, at between £60 and £80 a day (no VAT).

Our courses include:
•Phase 1 Habitat Survey
•Grasses, Sedges & Rushes for Phase 1 Habitat Survey
•Identifying Invasive Plants on the New Schedule 9 List
•Using the Wild Flower Key: Botany for beginners & the top 10 plant families
•Identifying Grass Indicator Species in Flower
•Advanced Grasses
•Plant Indicator Species for Phase 1 Habitat Survey
•Introduction to Aquatic Plants
•Sphagnum Identification & Ecology
•Introduction to Bryophytes as Indicator Species

There are still few organisations offering this type of botanical CPD training in the UK. Many are unaccrediated courses, which means that the quality of the teaching is not independently monitored. This is probably OK if the tutors involved have their work regularly checked anyway as they teach for universities or colleges or other awarding bodies with QA processes, but many courses never mention who is actually doing the teaching - and if they do, few state that their teaching is independently assessed. Being a professional ecologist does not mean that you know how to teach professionally! Professional teachers have to do CPD, just like ecologists, so they should be striving to improve their courses and, for example, have evidence to show that they can cater for mixed abilities in their groups.

It is also important to realise that attending an identification course is a great start, but that you need to practice regularly (by which I mean at least once a week, every week over the summer season) to retain and develop the skill....so as with any field of expertise, it helps if you really love the subject (and being outdoors)!

Clare

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Hybrid thistle

A local botanist, Phill Brown, found this strange looking thistle about 2 or 3 miles from where we live
You can see that it is quite a robust plant, with large, fairly flat leaves that are deeply lobed.



The inflorescence is similar to melancholy thistle Cirsium heterophyllum, but perhaps a bit narrower than normal. The top of the stem has no spines and only weak ridges or wings, which also almost fits with Cirsium heterophyllum. It would have no ridges on the stem at all. This is a character not found in most other British thistles.



The word 'heterophyllum' means variable leaves and Cirsium heterophyllum can have both unlobed leaves or lobed leaves like these. The dense cottony underside to the leaves is also a Cirsium heterophyllum characteristic.



However, the undulate (wavy) margin to the leaf with strong spines, does not fit with Cirsium heterophyllum and this photo shows a leaf resembling those from marsh thistle Cirsium palustre, but broader and more robust.



You can also see the undulate spiny margin on this more-or-less entire leaf from the same plant.

Additional characters that fit with Cirsium palustre more than Cirsium heterophyllum include: height (Cirsium heterophyllum is normally shorter); well-spaced leaves along the stem; long branches; and shoots all from a single rosette (Cirsium heterophyllum normally has lots of vegetative growth about the base). In addition, the plant was pretty infertile with only 8 normal-looking seeds from 3 flower heads.

Initially it was the overall 'odd' appearance of the plant, plus the combination of Cirsium heterophyllum type lower leaves and the degree and nature of the branching, that caught Phill's attention and caused him to suspect that he had found the (unfortunately named) hybrid between the two, Cirsium x wankelii. The combination of aditional characters from both Cirsium heterophyllum and Cirsium palustre listed above, helped Quentin Groom to confirm the identification. This is only the third record for this hybrid in England!

That process of identifying a hybrid by assessing all of its characters and comparing them to possible parent plants, is typical of how hybrids have to be identified. Hybrid identification probably qualifies as a 'dark art'. Part of the trouble is that you can rarely fit hybrids neatly in to keys to species, as they are too variable. This variability is often due to back-crossing (i.e. hybrid plants crossing again with one of the parent species. This means you can get hybrid plants that are very close morphologically to either parent and other hybrid plants at stages in between the two extremes. That is just too much variability to accomodate in a dichotomous key usually. Where there is not so much back-crossing, it is usually less of a problem and genuinely intermediate plants are more common. An exception to this involves Roses which have an unusual way of inheriting genes from their parents (split 20-80, instead of the normal 50-50).

Even without back-crossing, first generation hybrids are not necessarily intermediate in every character between the two parents. There are several reasons for this, e.g. some characters are associated with dominant and recessive genes, so the morphology in the hybrid plant will resemble the parent plant with the dominant gene entirely.

As they can be so tricky to identify, it is often useful to collect some more information about the plant. What other species from the genus are growing nearby? If both potential parents are growing right next to the hybrid that is reassuring, but not absolutely necessary or conversely, not absolute proof in itself.

Most hybrids are at least partially sterile and so at least some will not form viable seeds. Sterile seeds often look shrivelled and empty compared to viable ones. However sterility in hybrids can vary between 100% and 0%. For this character to be useful, you really need to have some knowledge and experience of what the normal range of sterility is for the particular hybrid that you are dealing with. This information is not included in popular books, so you need to have access to specialist texts, or to someone with a particular expertise in the group of plants you are dealing with.

Hybrids often have some sterility in their pollen. This can be checked easily under the microscope by putting some pollen in stain. The viable pollen is usually coloured and full, whereas the sterile pollen appears shrivelled and colourless. You simple count how many of each type you have and from that work out the percentage fertility. Again for the results to be meaningful, you need to have some experience with the particular hybrids.

On top of all of that, of course, sterility can be caused by environmental factors, so just because you have some sterility, does not mean necessarily that it is a hybrid!

This all sounds complicated, but it is really a simplified account of some of the factors you consider with hybrids. It is no wonder that most people interested in plants groan in despair at the mere mention of the word hybrid.

John

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