Friday, 18 August 2017

The 'Grey Man' of the British Flora

The 'grey man' concept is about surviving by never drawing attention to yourself, blending into the background, giving no lasting impression. Sea Pearlwort (Sagina maritima) has this down to a T. Poor thing.

Photo by Geoffrey Hall, NatureSpot website for Leicestershire & Rutland

I suspect I have been overlooking this annual species, and I suspect this will be case for many others also. Particularly those like me who largely botanise inland and therefore do not have this species on their radar as a possibility. Mike Wilcox has recently drawn my attention to the presence of this species at St Aidan's (VC64), and having been for a look I had seen it previously and just ignored it as seedling Procumbent Pearlwort (Sagina procumbens). How wrong I was. After this I found it in pavement cracks in Leeds (VC63). Mike knows this species well from Bradford, about as far from the sea as you can get.

Photo by David Nicholls, NatureSpot website for Leicestershire & Rutland

Part of the problem is that this species is very variable, and many populations comprise tiny plants (2 pence coin size), so it is easily missed. Published descriptions are also not adequate, for example in Stace it is described as 'diffusely branched +/- erect annual'. Not strongly prostrate as per my plants and the photos above. The associated key also links the species to other annual species, the unintended mental image of which (coupled with the description) is a plant similar in character to these other species. The key jizz of the plant as shown above is a central rosette with flowering branches arising around its margins, and no sterile shoots (unlike the perennial species).

I was please to have opportunity again to use my bargain £10 macrolens for my iPhone. Quite pleased with the result below.

Sunday, 13 August 2017

It's Hawthorn Time

I've blogged previously on the abundance of Eastern Hawthorn (Crataegus x subsphaerica), but there are still very few dots in the BSBI database other than mine and those for Cambridgeshire, Cardiganshire and the London area.

Now (and until well into October) is a great time to go out and look. Look and ye shall find, probably very quickly. The sepals are rising! See my other posts (link to Crataegus in side bar) for typical forms. But if it has erect sepals it is probably (given its abundance) Eastern Hawthorn, or potentially its much rarer parent Saw-toothed Hawthorn (Crataegus rhipidophylla). There are other hybrids, but if in doubt over parentage there is usually a bush nearby showing a clear influence from Hawthorn (Crataegus monogyna).

Once your eye is in on leaf shapes and fruit characteristics, it is quite easy to spot suspect bushes. Particularly if showing hybrid vigour or if they have the large distinctively-shaped fruit.

Its more tricky with the form with reflexed sepals (nothovar. subsphaerica), particularly when closer to Hawthorn. But again large fruit, and the longer than wide sepals, will give the game away in many cases. I found a nice bush today, photo below

Both forms are widespread around Leeds as plantings, but are also widely naturalised and show the characteristics of a hybrid swarm, with all possible variants from one extreme to the other due to back-crossing. However, most are somewhere in the middle.

Sunday, 6 August 2017

The World's Smallest Centaurium pulchellum?

During my recent July 'botanise-athon' I popped into Fairburn Ings, I fancied seeing what the river had to offer and wanted to have a look at the dog-roses in the knowledge that Rosa canina is soon to be formally split (at least in terms of our standard literature) into three species (canina, corymbosa and squarrosa) rendering most records to-date to aggregate status.

Anyway, I went round to the boot of my car to put my walking boots on and there at my feet were lots of a tiny Centaurium. Of course I new Lesser Centaury (Centaurium pulchellum) was here as a dwarf form, as Phyl Abbott had found it a couple of years previous new to VC64. I just thought I would need to do a lot more looking to find it. It was associated with the narrow strip of gravel along the edge of the car park, so I assumed it had been introduced with this substrate. It is a very rare plant in Yorkshire and indeed this far north where it is mainly coastal.

However, this was not the last I saw of this little gem. Pottering round an area of acid grassland, where there were extensive bare patches where water stands in the winter, I was surprised to find 100's of plants. All tiny and predominantly single stemmed with just one flower on top. Clearly this is a dwarf race, breeding true and undoubtedly maintained by selfing, rather than just an environment induced phenotype. Being so small I doubt it is troubled by pollinators any more, so it has painted itself into a bit of a genetic deadend. But it seems quite happy at the moment and should persist as long as there are areas of bare ground with no competition from larger plants.

Elsewhere there some great stands of Honeysuckle (Lonicera periclymenum var. periclymenum).

And a small colony of this garden favourite, Rose Campion (Silene coronaria).

Sunday, 30 July 2017

Hackfall Wood (VC64)

Just coming out of a week of intense recording, I finally have some time to share some news. Between the trips out, the late evening pressing of dog-rose collections, and the associated data entry, time has been limited

One of my first trips was braving an unpromising rainy day to head up to Hackfall Wood.  What a site, I thought it would fill half a day until the weather cleared but I ended up filling a day pottering around the various paths and I still left feeling there was more to see. The plants were exceptional, helped by proximity to a boulder strewn section of river dripping in vegetation, with each boulder with its own mini hanging garden. However, the experience was added to by the various 18th century gothic follies hidden through the wood.

Giant Bellflower (Campanula latifolia)

Harebell (Campanula rotundifolia subsp. rotundifolia) on riverside boulder

The trip was spur of the moment, so I quite forgot this site is famous for its thriving population of Wood Fescue (Festuca altissima). So when I stumbled over my first patch, there was much head scratching until it clicked into place. A new species for me. Its here in its hundreds dripping from the rock outcrops and slopes below.

Plenty more widespread species added to the interest.

Bifid Hemp-nettle (Galeopsis bifida)

Goldenrod (Solidago virgaurea subsp. virgaurea)

Common Cow-wheat (Melampyrum pratense subsp. pratense var. pratense)

The final highlight of a great day was the biggest stand of Great Horsetail (Equisetum telmateia) I have ever seen, easily 100 x 10m in area. This is an uncommon species in VC64.

Sunday, 23 July 2017

Coritanian Elm?

I can't claim to be an expert on elms. I am just old enough (wrong side of 40) to remember my father felling mature trees during the early 1980's as a result of Dutch Elm disease, but have no memory of them as a major tree in the landscape. It wasn't until I moved to Peterborough in the 2000's that I had my first experiences of mature elm trees. Huntingdonshire remains blessed with a fair number of mature elms, most of which are tall stately trees that I have interpreted to date as Small-leaved Elm (Ulmus minor subsp. minor) in the broad sense, as per current British  convention.

However, on last Sunday's trip down to Grafham Water (VC31) I found a notable concentration of a very distinct elm that did not match my understanding of the above species to date. Several mature trees are present at Perry, being notable for their short height (less than 20m), broad spreading and twisting limbs, and most strikingly dense epicormic growth over all major limbs. Of course all leaves suitable for ID were firmly out of reach. After a couple of hours digging around, I have come to the tentative conclusion that these trees seem to be a reasonable match (based on limited descriptions) of trees known previously as Coritanian Elm (Ulmus coritana). If so, it is notable to find mature survivors. Regardless of the ID they are a distinctive part of the surviving variety of mature trees in the county.

Monday, 17 July 2017

Stripey Calystegia

A quick post to start catching up on recent news. A trip to Grafham Water Lagoons (VC31) this Sunday with the HFFS turned up this attractive form of Large Bindweed (Calystegia silvatica subsp. disjuncta) with broad pink stripes on the outside of the corolla (var. zonata). The stripes are arranged outermost when the flowers are in bud, resulting in striking pink buds that contrast with the flowers. This variety only seems to have a few records in the BSBI database. Rare or overlooked?, my observations to date suggest the former.

As a postscript. Going for a walk around Woodlesford (VC63) I saw other examples of the species with very faint barely perceptible pink tinging where the stripes of var. zonata would be. The buds were white or with a patchy hint of pink. So it seems this variety is at the extreme end of a spectrum of variation in the species, and  var. disjuncta is not necessarily pristine white in all cases.

Saturday, 24 June 2017

Teeny Tiny Things

Back to Skelton Lake (VC63 and 64) where the drawdown flora is just starting to develop. Much of the strandline has been exposed for a while and is very dry, so we will either need some rain or further drawdown to wet mud if the site is to live up to its potential.

Much of the flora was miniscule. However, it was a great opportunity to test my new toy, a x10 macro lens you can just clip onto a smart phone. Did a good job and a bargain at £10 from Amazon. I will have to see if there is a lower magnification version, as with x10 you are nearly on top of the subject before it comes into focus. Fine for plants, but critters are likely to be less obliging.

Anyway the results below. Best find was Sand Spurrey (Spergularia rubra), hiding amongst the Buttonweed (Cotula coronopifolia) which was also very small but towered over these plants. Also present was Pink Water-speedwell (Veronica catenata) and Swinecress (Lepidium coronopus). In sequence below.