Tuesday 4 November 2014

Last days of summer


 
'No shade, no shine, no butterflies, no bees, no fruits, no flowers, no leaves, no birds, November.'  Thomas Hood sums up my feelings on this month rather well, but this year October seems to have been given an extension and it has extended warmth and sun into the eleventh month.  I was in Dorset to look at ways of roughing up some of the heaths.  It was bright but cold: not a promising day for insects, but we found the leaves of Pale Heath Violet Viola lactea along the tracks, and some nice clusters of Nail Fungus Poronia puncata on pony dung.

 
But the highlight came at the end of the day as we were diverted across the railway and around the building works at Wareham station.  The disturbance had produced a small crop of Annual Mercury Mercurialis annua by the path, and I noticed that something had been munching at the leaves.

 
 
Two of our weevils are often found late in autumn on their host plants, one for each of our Mercurialis: Kalcapion pallipes in woods on Dog's Mercury, and Kalcapion semivittatum on Annual Mercury. I do not know whether the adults feed on leaves, but I thought it was worth checking to see whether the damage had been caused by Kalcapion semivittatum, a very scarce insect I had never found, despite searching almost any bit of Annual Mercury I find.
 

I peered in among the stems and flowers trying not to touch the plants and cause any lurking weevils to panic and drop to the ground where they would be very hard to find.  And yes, after a minute or so of staring I found one: hurrah.  Small, and greyish because of the covering of white hairs, with yellow legs and the characteristic bare patch on the middle of the elytra.  In any other species I would assume this was where the hairs had rubbed off, but even the freshest adult Kalcapion semivittatum has this spot, which, rather than being bald, is caused by the hairs being brown unlike the white ones that coat the rest of the body.  Now, I must go and find a wood and look for pallipes before November really does arrive.


 

 

 

Thursday 4 September 2014

Vision in pink


Our first stop at Arne was a yard where timber and other materials had been dumped.  Vehicles have disturbed the ground here, leaving seasonally wet bare ground: just the place to look for rare plants.  Mossy Stonecrop Crassula tillaea was here, growing next to the shocking purple and yellow flowers of Sharp-leaved Fluellen Kickxia elatine.  I pointed to a corner of the site and announced to the trainees that it was the kind of place I would look for good things.  I was unusually proved right when I found myself walking over a some tiny strands of Coral Necklace Illecebrum verticillatum.


The whorls of hard, pointed white flowers, like mouse teeth are unique in our flora, making this species easy to recognise despite its smallness.  It is one of the characteristic plants of dry ponds in the New Forest, like some of the species we saw yesterday, but David Pearman points out that while it has been known from Cornwall for over 350 years, it was not discovered in the Forest until 1925.  Pennyroyal Mentha pulegium  and  Small Fleabane Pulicaria vulgaris had both been found over 80 years earlier, and it seems incredible that botanists who had found these plants had not noticed Coral Necklace at the same time in the same places.


It was unknown in Dorset until the 1980s, but it is now abundant at Barnsfield.  Some of the Arne machinery works at Barnsfield, so there is little doubt that it has arrived here on vehicle tracks.  These small annuals of wet ruts on heaths must have been travelling on cart wheels and horse hoofs for hundreds of years, and I am tempted to see tractor tyres as the modern equivalent, and part of the semi-natural dispersal of the plants.


Trailing Tormentil Potentilla anglica is a plant I rarely find.  I often see the hybrid between it and Creeping Cinquefoil Potentilla reptans or between Creeping Cinquefoil and Tormentil Potentilla erecta, both of which can look very similar to it: the large flowers with four or five petals suggest a mix of Tormentil (four petals) and Creeping Cinquefoil (five petals) genes.  The three-lobed leaves are another feature that is wrong for either parent (leaves five-lobed in Creeping Cinquefoil, three-lobed with large jagged stipules in Tormentil).  Plants like this are common, but I usually find that they are sterile, which suggests they are hybrids rather than Trailing Tormentil. 
 
 

Today's plants had ripening fruits hidden behind their sepals (see photo below), demonstrating their fertility, and I was happy to call them anglica, a species formed by an ancient hybrid between reptans and erecta, which doubled its chromosomes and became fertile.

 
 
The last of today's special plants, Dorset Heath Erica ciliaris, is another frequent hybridiser.  It is on the right, with its distinctive pyramid of flowers, each of which has a down-turned spout, two features that set it apart from our other heathers.  On the left is its hybrid with Cross-leaved Heath Erica tetralix.  The hybrid has a round head of flowers like tetralix, but there is a hint of a spout and they are darker pink.  The surest way to separate the three is to look at the anthers: tetralix has a pair of long white horns sticking out the bottom of its anthers; these are absent in ciliaris and present but much shorter in the hybrid.
 
 
Animals are much less prone to such shenanigans, and there is no difficulty is recognising today's star, the pretty crab spider Thomisus onustus.  Both the abdomen and head are drawn out into a pair of points, those on the head having an eye at the end, like a hammerhead shark.  It usually comes in pink, but it can become white or yellow if the mood takes it.  Pink is definitely best for hiding among the Bell Heather and ambushing visiting insects.  It is a rare spider in Britain, where it is found on heaths between Dorset and Surrey: it seems to shun those further east, west, or north.


 
 

Wednesday 20 August 2014

The spider from the Emerald City


One of the highlights of today's invertebrate training course was this little crab spider on the oaks.  One of the participants had asked what we would find on the different trees, so I gave her a beating tray and suggested she find out.  We were showered in Birch Bugs Kleidocerys resedae from the birches, Yew yielded little, but the oak gave us Diaea dorsata, which looks as though it is made of emerald and would fit in well on the buildings in the capital of Oz.


Here it is in typical crab-spider pose, with its long front two pairs of legs held out and close together.  Down on the heath we found Heather Beetles everywhere: on the heather and all over the path in thousands.  It will be interesting to see what effect this has on the heather next year.  A lot of it is looking rather brown now.

A bit further on we came to the fence posts that are well known locally as the place to find Marpissa muscosa, which was at home in its usual spot.  This is one of our largest jumping-spiders, appropriately called the Fencepost Jumper, and it is as adorably cute as most jumpers are.  I underestimate the ability of these spiders to tackle large prey, but as these photos from the spring show, they are capable of grabbing a quite substantial meal and holding it down.



Sunday 22 June 2014

Happy birthday, Tyler


James and I celebrated Midsummer's Day by going to the Breckland to look for some of the special beetles of disturbed ground.  The widening of the A11 has created some excellent conditions for these species as weeds have appeared in abundance on the spoil and bare areas along the side of the new road.  Near Thetford there are some stretches dominated by Flixweed Descurania sophia, which is host to a couple of uncommon weevils.


The bigger one is Ceutorhynchus rapae, similar to the common obstrictus, but with a slightly different pronotum shape.  It is separated in the keys by the tooth on the hind femora, but this can be very small and easily overlooked; one of my specimens does not seem to show it at all.  An easier distinction is in the claws, which are brown and toothed in rapae, black and slender and untoothed in obstrictus.


 

The small one is Ceutorhynchus pulvinatus, more densely covered in white scales but otherwise like the very common typhae.  The rare species can be identified by its swollen pronotum, like a moghul dome, and the long last tarsal segment.

The Flixweed was growing with other ruderal and waste-ground plants, including some nice Tower Mustard Arabis glabra, Corn Chamomile Anthemis arvensis, and the delightfully named (in English and Latin) Loose Silky-bent Apera spica-venti.

  


How long will this resource last?  I hope the authorities will not destroy it all by planting the road verges or sowing them with grasses and killing off the rare plants, but they usually do, spending thousands of pounds in the process and calling it greening or landscaping, which is just a euphemism for destruction. All it needs is a bit of disturbance every now again and this could be a refuge and a corridor for many of the scarce Breckland species that are in decline because there are not enough rough corners and disturbed tracks in the countryside.

You could not complain about a lack of disturbance at our next site.  The ground next to the power station is used by scramblers, karts, and other vehicles, which have churned up the sand and made a lot of bare ground.  There is perhaps too much disturbance here, but at the edges of the tracks some plants are able to establish themselves.  When we arrived we were somehow recognised as entomologists by some of the fathers of karting children.  They wanted to know what the black and yellow bugs were that were accumulating in the footwell and front of the kart as it was racing through the vegetation.  We were able to confirm that they were Cinnabar caterpillars as one of them had suspected.  We learned that Tyler, one of the kart drivers, was a keen entomologist himself, and he was here celebrating his birthday with some friends.  Later, James was called over by Tyler to examine the by-catch again.  When he returned with Tychius quinquepunctatus in a tube I was almost speechless.  Actually, I had plenty to say, but none of it is repeatable here.


I had just been handed one of our rarest weevils, but we had no idea where it had come from.  This species feeds on vetches, which were not much in evidence among the churned up sand.  We asked the karters where they had been, and we followed their route and looked among the legumes around the edge of the site but we could not find any more.  So the provenance of the weevil is a mystery.  It must have come from somewhere on the site, but who knows where?  Nevertheless, it was a remarkable find, even though it had lost a few scales and gained a bit of dust during its journey among the seed and sand in the footwell.  Many happy returns, Tyler.








Sunday 1 June 2014

Would Whites?


A sunny start to June and I had a free Sunday; it was a day to go out and see something.  Col and I headed west to Salcey Forest hoping to see some Wood Whites Leptidea sinapis.  I was not sure where to go, but we parked up, Col got out and immediately said 'That's that one, isn't it?' and went across to the opposite side of the car park where a white butterfly had just landed.


He confirmed that we had indeed found our quarry within ten seconds of arriving.  Here it was perilously drinking from mud just behind the back wheel of a butterfly-squishingly heavy car.


There were three others doing the same at the edge of nearby puddles, and we found another as soon as we crossed the road.  Hurrah for co-operative insects.







Sunday 13 April 2014

Ghost plants


Last week my dad sent me some plant photos to identify.  I opened them when I was on the phone to mum and said 'Bloody Hell' when they came up on the screen.  For there was a group of eerie Toothwort Lathraea squamaria spikes looming out at me.  This is not such an uncommon plant in parts of Britain, but East Anglia is almost devoid of it and I had never seen in my home county, let alone the wood where I spent a lot of my early days botanising and birding.  So today, with the sun and the bluebells both out, I went back to Stevenage to see the new-found Toothwort for myself.



I do think it is rather an ugly plant, or perhaps unkempt would be fairer, but it is nonetheless beguiling, perhaps because it looks so unplant like.  There is something about its texture that gives it the look of bone and scales; teeth set in a jaw is an apt analogy.  So is Audrey from Little Shop of Horrors if you look at each flower individually when they are young with gaping mouths (see the photo at the top).



All this strangeness is possible because Toothwort has no need for leaves or greenery because it attaches its roots to those of another plant and helps itself to the good stuff.  All you see is the flower spike when it emerges through the leaf litter.  As with all the other Toothwort I have seen, these spikes were growing under Hazel Corylus avellana, which is the usual victim in Britain.



That was the morning's activity.  In the afternoon I went to Potton Wood, which can be relied upon to provide Marsh Tits.  It is also home to a small population of Oxlips Primula elatior, which seems to be getting smaller because of deer, brambles, and shade.  There were a still few flowers, but only a few.  For how much longer will Bedfordshire be able to claim Primula elatior as part of its flora?  The rest of the spring flowers were looking good, with Bluebell Hyaconthoides non-scripta, Lesser Celandine Ranunculus ficaria, and Wood Anemone Anemone nemorosa providing colour in the dappled shade.  And a couple of Marsh Tits.


Wednesday 9 April 2014

Delusion


This is one of my favourite plants.  The Summer Snowflake Leucojum aestivum has an enchanting English name, crisp white lampshade flowers that dangle seductively from the top of a neat stalk, each petal tastefully adorned with a pure green spot, and shiny green leaves with a squeaky texture that arch out from the base of the plant.  It is a beautiful thing to start the flower season with.


After my meeting at Wallingford today I had a quick walk down to the Thames to admire the snowflakes.  They were growing along the edge of a small inlet rather than along the river itself, among nettles and willows as is often the case.  Summer Snowflake is listed in most British floras as a rare native, but I do not see how it can be.  I wish it were.  How I wish it were: it would lovely to have it as one of our native plants.  But to give it native status you have to ignore so many things.  First, it was not discovered in the wild until 150 years after it was first recorded as a garden plant.  It was first found wild between Greenwich and Woowich in 1788 in a place where its discoverer thought 'no garden could ever have existed', but downstream from any number of London, country estate, or Oxford college gardens.  Second, its supposedly native distribution is arbitrarily defined as the Thames and its tributaries.  Perhaps including the Somerset Avon too.  And the Meon in Hampshire.  And Maybe Littlehampton in Devon.  Possibly even in Suffolk.  In other rivers the plant occurs in no less wild situations as an acknowledged escape from gardens.  These show that Summer Snowflake can establish itself along rivers and take on the appearance of a natural part of the vegetation.  Why are some of these considered native, while others are not?  (The assertion that the obvious escapes are all Leucojum aestivum subsp. pulchellum and that subsp. aestivum is not grown in gardens is not true.  I have seen subsp. aestivum in Norfolk, where its grows with Spring Snowflake Leucojum vernum, both clearly the descendants of garden plants.)  The places I have seen it are rather uncomfortably near gardens, some of which even have snowflakes in them, and I see no reason to assume that the wild plants were moved to the garden rather than the other way around.  Last, as David Pearman has found out, it does not seem to be regarded as a native in any of the adjoining countries on the continent.

 

So I would love to believe that the Summer Snowflake belongs here, but it does seem to be a plant of southern Europe.  But, like the Fritillary Fritillaria meleagris, another plant that has traditionally been thought of as native but whose credentials fall down when you look at them objectively, it seems a harmless addition to our flora and it it has a place in the history and culture and heart of the few areas where it grows wild.  So in that sense it does belong and we should look after it.

Monday 24 March 2014

Fond farewell


I had only a couple of hours this morning before I had to leave for the airport.  I spent the first of them among the orchids on the slope below the cabin.  Ophrys orchids are one of the best things in the world.  Among David Attenborough’s prolific outputs is a series called Attenborough’s Ark in which he chooses his favourite and most extraordinary animals, those that he would save on an ark if there were a cataclysmic disaster.  Ophrys would be in my ark.  First, they are so pleasing to look at.  The neat spike of flowers is a work of architectural excellence, and each floral decoration is full of character.  Two side petals to suggest ears; the pollinia or small glands are a pair of eyes; and the lip is a nose or a whole body with arms and legs if you fancy.



Then there is the pattern and texture of the lip.  It seems so velvety and soft and it contrasts perfectly with the almost plastic-looking speculum (the smooth bit in the middle).  I think this is part of the appeal: instead of being part of the natural world, the flower looks as though it is artificial, even though it is not.


All this is very attractive, but we haven’t even considered the amazing biology behind it.  When I first heard about it I couldn’t believe it: it does what?  It turns out that the flowers are not like this to please me but rather to fool a male wasp into mating with them.  All the colours and textures are there to mimic a female insect.  The visual and sensual cues are supplemented with pheromones.  All this is so convincing that passing males will eagerly mount the lip and get the pollinia stuck to their head.  They will carry these to another orchid flower if they try to have go on that one too.

The Mediterranean is the centre of diversity of Ophrys: there are many more species here than further north (only four in Britain).  How many more is a matter of fierce debate.  The trend, as in most plants and animals, has been one of recognising more and more species.  This has been taken to the extreme by Pierre Delforge’s book on Orchids of Europe, which lists 251 Ophrys species.  If you flick through the pages you will find dozens of seemingly identical plants all given different names and separated by rather inconsequential features.  To me, some of the photos contradict the descriptions and keys and they do not make a strong case for separating all the entities he has named.  He has described even more species since.  Other people have found this approach too much, and they have produced genetic evidence to suggest that it would be more sensible to recognise only a dozen or so species, each of which is more readily separable from the others but has many local forms, some of which are produced by ancient or modern hybridisation.

 

On my hillside I found myself in agreement with the lumpers.  I looked at the amount of yellow around the edge of the lip, the shape of the speculum, and its colour.  I could see as much variation here, sometimes even within the same plant, as there seemed to be between some of the Delforgian species.  I was happy to call everything Ophrys fusca, apart from a couple of lutea that were not quite in flower.

I went up to the limestone rocks above for a last time, past a couple of Orchis conica that I had overlooked.  The Iris planifolia was now gone over, but Mediterranean Spurge Euphorbia characias, a plant that I associate very much with holidays, was in flower.




The pretty little Veronica cymbalaria, one of the week’s common plants, was here too, and I found a not too flighty Spanish Festoon and Provencal Hairstreak.  And with that it was time to stuff as much ham and biscuits as I could into my luggage and go back to Britain.


A final word of thanks to the Departamento de Biología Vegetal at Universidad de Málaga, and the publishers who have made the floras (one each for eastern and western Andalucia) available online for anyone to download for free.  Both are extensively illustrated, the western volumes with line drawings of every species, and the eastern set with beautiful photographs, making them much easier to use than most keys.  Does anywhere else in Europe have such a useful and readily available identification resource for visiting or resident botanists?  Congratulations once again to Andalucia on taking the lead.


I also need to mention Flora Iberica, which was very helpful once I got back to an internet connection.  Like the Andalusian floras it is available online, thanks to the Real Jardín Botánico.  I cannot praise highly enough the public spirit of these institutions in making works available so that anyone can enjoy and appreciate the wonderful plants of Spain.