Musings

Wednesday, October 28, 2015

Yellow Dung Fly


I thought we might be overdue diptera so here are a pair of mating Yellow Dung Flies, Scathophaga stercoraria, at it hammer and tongs up on the Downs. The male is on top with the fancy golden hairy pantaloons. They are one of the commonest flies in the world, their distribution reflecting that of human animal husbandry. 
They are also one of the most studied organisms in the world, lending themselves, like their prey and smaller cousins the fruit fly Drosophila melanogaster, to scientific experiment as a result of their rapid reproductive turnover.
The female lays her eggs on fresh dung and the larvae grow through three stages over five days. They then spend a further five days emptying their stomachs before burying down beneath the dung to pupate.
The young flies are anautogenous, which means they can't crack on with the sex until they've fed up for it. 
No shit!

Shepherd's Purse




Another annual ruderal species which is common round us in Sussex. It is appropriate to find it on the Downs, whose landscape and habitats are a direct result of sheep grazing over millennia, for it is known as Shepherd's purse, Capsella bursa-pastoris. It is a member of the mustard family, Brassiaceae and not a native but an archeophyte. 
An archeophyte is a naturalised plant introduced before 1492 (yes, Columbus and all that) whereas after that date such plants are known as neophytes. 
The reason for its common name (a direct translation of the Latin specific) is the shape of the seed pods apparently resembling the purse carried by shepherds. Which shepherds and when is hard to discover.

Common Eyebright agg.


Beautiful, beguiling, but very very tricky. Even the Plant Crib (BSBI) is coy when it comes to identifying this group, referring you to other monographs on the genus and to Stace. I believe there is a BSBI Handbook under construction but in most accounts the Eyebright, Euphrasia officinalis agg. , is usually not identified to the species, sub-species, or hybrid level. Essentially it requires an expert to come and see your plant in the field to make a confident stab at it. 
They belong to the Orobanchaceae family (I think I've posted Common Broomrape if you are interested to search) which have in common that they are all parasitic or semi-parasitic on other plants. In the case of the Eyebrights the grasses provide the without-which-not. 
The common name derives from their use in the treatment of eye conditions such as conjunctivitis and blepharitis, both as a decoction and a poultice. 

Red Clover




















This is Red Clover, Trifolium pratense, a member of the bean family, Fabiaceae. As such, it has the special root nodules containing bacteria which fix nitrogen, making it widely planted as a soil improver. I had thought it was another annual, but it is in fact a 'short lived perennial'. I'm not exactly sure what the definition of 'short lived' might be, but suspect at least three years (or it would be 'biennial') and fewer than thirty.

Common Knotweed




Another common annual - this is Common Knotweed, Polygonum aviculare. It is in the family Polygonaceae which contains all the docks and buckwheat. The Latin derives from 'many knees' as the nodes of many species are swollen, looking like knees. The papery stipules form a sheath known as an ochrea

Scarlet Pimpernel




Another common ruderal species found on light soils, this annual is Scarlet Pimpernel, Anagallis arvensis. Emma Orczy's eponymous fictional character is named after the plant, which featured on his calling card left to goad his enemies. It flowers for most of the year and belongs to the same family as the Primrose. 
I must apologise for the hiatus in publication. This is due to a holiday on Gran Canaria which has inflicted deep lassitude through excessive hedonism. I am trying to overcome my predicament.

Thursday, October 22, 2015

Spanish or Lusitanian Slug

Hmmm, time for another mollusc. Not as cute as the Door Snail but certainly commoner, in the south at least. This is an invasive species, originally referred to as the Lusitanian slug but now usually known as the Spanish Slug: Arion vulgaris. It lays more eggs than our native slugs and they are more resistant to drought. It also has a less discerning diet.
This one is chasing a leucistic cousin. 


Wednesday, October 21, 2015

Bristly Oxtongue







 Something of an oversight not to have posted this common 'weed'. It has distinctive blisters on its leaves and distinctive out involucre bracts that look like hairy sepals (see top left picture). The seeds are 'beaked' which means that there is a stalk between the top of the seed and the pappus parachute. It's not terribly obvious but you can just about make it out in the bottom right seed.
And it is called Bristly Oxtongue, Picris echioides
(Rose (see useful books) warns us that another plant has leaves with blisters: Green Alkanet. I'll look out for it and post if I find any.)



Hemp-agrimony




















I didn't manage to post anything yesterday as it was Matty's 18th birthday and after work we were straight to the restaurant to celebrate, getting back late. However, on my way back to the car I came across some Hemp-agrimony flowering well on a north-east slope behind the hospital. Eupatorium cannabium is derived from Eupatoria (agrimony) and the Latin for hemp.

Monday, October 19, 2015

Sunday, October 18, 2015

Agrimony




So this is today's post (as opposed to the previous post, which was in fact 'yesterday's' post). It's another plant I'm surprised I haven't done before as it is, like Selfheal, common, especially round these chalky parts.
It is Agrimony, Agrimonia eupatoria, a member of the Rose family. 
You can tell it's not Fragrant Agrimony because it's not 'up north' and also the receptacle cup's hooked bristles are all pointing forwards or at most horizontal, as opposed to reflexed. 

Selfheal




And there was I thinking I'd posted something yesterday. Wrong! I think I got distracted after I put my back out in the process of unblocking one of our most important drains: the one that takes the waste water from the washing machine. (We had developed a grey-water spring that appeared in the flowerbed outside the back door every time we used the washing machine over the last week.) A judicious cocktail of drugs and the diversion of Keef's 50th birthday bash conspired to make me forget the blog.
Anyhow, a short but scenic autumnal stroll with Abbey and Molly along the Downs to Itford Hill from Beddingham Hill threw up a number of interesting species.This, Selfheal or Prunella vulgaris, I thought I'd already posted, but apparently not. So here it is. 
It's a member of the Dead-nettle family, Lamiaceae. 

Friday, October 16, 2015

Marsh Thistle





















Not dissimilar to Creeping Thistle, this is Marsh Thistle, Cirsium palustre. Distinguished by the spiny-winged stems with sessile hairy leaves. Another member of the Asteraceae.

Narrow-Leaved Michaelmas Daisy





I was going to do a quick post last night of what i thought was plain old Michaelmas Daisy, but oh no, there's no such thing as a Michaelmas Daisy! It turns out that there are a group of difficult to distinguish species and hybrids roaming the British countryside. 
So having plodding through the keys in Collins, Stace and Rose, I reckon on this being Narrow-leaved Michaelmas Daisy, Aster lanceolatus. The reasons are as follows: it has only just started flowering (Sept - Jan given as range); it has very pale ligules; non-clasping, narrow leaves; glabrous (no hairs); involucre bracts not widest below the middle (which is a characteristic of Common Michaelmas Daisy, the only other contender). 

Wednesday, October 14, 2015

Tamarisk








This caught my eye yesterday when walking up to my car past the allotments behind the hospital: Tamarisk, Tamarix gallica. It is not uncommon in sandy, seaside locations, often planted as a windbreak where it will tolerate dry, salty conditions. It is introduced from around the Mediterranean, being endemic to Saudi Arabia and parts of North Africa.

Tuesday, October 13, 2015

Dogwood






















This is noticeable at the moment: Dogwood, Cornus sanguinea. It is one of the first to but on a good display of autumnal colour and currently the A27 is lined by burgundy-leaved specimens some of which are flowering a second time. It has an unusual characteristic in that you can carefully pull the leaf into two parts and it will remain connected by the phloem which consists of spiral cell assemblages (see bottom right photo).
There is a fascinating etymology for Dogwood: one theory is that the name derives from the Old English dagwood. Dags (arrows, daggers, sharp pointy things) were made from its hard slender stems. The The Canterbury Tales it is referred to as 'whipple-tree' after its use in carts for a section that connects the cart to the horse.