US social scientist Kenneth Boulding : ‘If you believe exponential growth can go on in a finite world, you are either a madman or an economist’.

Sunday, 12 July 2009

12/7/09: Encountering new species in Erith

Continuing my walk home from Lesnes Abbey (the long way round), I crossed Bronze Age Way into Erith (a road that is a classic example of crazed 20th century car-dependent thinking, long after everyone should have known better - and a blot on the landscape right next to a perfectly serviceable railway line).

This time I checked out the uncut field on the east corner of Church Manor Way, ringing with the sounds of a less usual type of grasshopper/cricket, whose whereabouts I just couldn't pin down, even though some sounded like they were outside the fence.

There were the usual suspects for the area such as Creeping Thistle, Common Mallow, Common Ragwort, Mugwort, Rocket and Field Bindweed, but also Wild Carrot, a clump of Horseradish and several Teasel.

Most distinctive were a couple of patches each of sprawling, floriferous legumes, one type with clusters of yellow flowers and one with strongly red-purple flowers. They were just a bit too far inside the fence to be able to get hold of and have a proper look, and I didn't have my binoculars. But the short of it is that my initial determination is Sickle Medick (Medicago sativa), a totally new species for me. Subspecies falcata is native to East Anglia but has been introduced elsewhere. Francis Rose ('The Wild Flower Key') says it hybridises with Lucerne to produce plants with flower colours extending to purple-black. It so happens that there are Lucerne plants just up the road, in a strip of land between Lower Road and Bronze Age Way.

Sickle Medick (???)

Hybrid (foreground) between Sickle Medick and Lucerne (???)

My primary objective had been to photograph the Ivy Broomrape (Orobanche hederae), in St John the Baptist Churchyard, Erith, at the junction of West St and Lower Rd. I'd visited two weeks ago, having read in the past that the species occurs here, but my mobile phone was out of juice at the time so I hadn't been able to take any pictures. I did, however, count some 378 flower spikes - and that almost certainly wasn't all of them.

The leafless ivy parasite Ivy Broomrape, St. John's churchyard

Ivy Broomrape occured in three places near where I lived in Bristol, but here the flower spikes were sometimes feet from the nearest bit of Ivy, coming up in grass between graves.

According to the London Wildweb website, 'ivy broomrape [is] a nationally scarce species, [here] growing on Atlantic ivy (Hedera helix ssp hibernica); this is thought to be a recent colonisation from a nearby native population.'

Now in flower, I was able to confirm that an umbellifer under the gate by the Scout hut on St. Fidelis Rd was Fool's Parsley (Aethusa cynapium), with its distinctive narrow bracteoles hanging down from the partial umbels. This is another of those species described as 'common' that doesn't crop up very often, and it's the first time I've found it in Bexley.

Fool's Parsley

There was a plant of Shaggy Soldier in the road gutter at the end of Pleasant View.

This extensive, dense webbing, was draped over Cotoneaster at the bottom of Stonewood Rd, with no obvious occupants - but I didn't take a particularly careful look.

The narrow bank at the foot of Bexley Rd, high above the descending Fraser Rd, had an interesting flora, and there were hints of past cultivation before, one suspects, it was deemed too dangerous to continue.

There were about nine violet-blue-flowered plants of Viper's Bugloss (a better view to confirm ID was achieved with binoculars on 26 July), a new Bexley record for me, plus lots of Opium and Common Poppy, 'feral' cabbage type plants, some white-flowered Red Valerian and an unidentified (presumed non-native) grass with very large seed heads.

Opium Poppy seed heads

Viper's Bugloss (Echium vulgare) with Prickly Lettuce

An interestingly 'exotic' grass

No comments:

Post a Comment