Sunday 29 June 2014

Down to Whetsted Gravel pits

As I got down to East Lock I paused to check for insects and particularly hoverflies at the wild-flower seed enhanced area just north of the lock. I had by now seen several Eristalis pertinax and here was my first Sphaerophoria female of the day, hovering about the Perforate St. John's Wort, Hypericum perforatum.


There was also this very nice hairy red beetle, which I feel should really be recognizable to someone if I had the gall to put this single side view on ispot !


While I was looking at the pictures of this Lesser Stitchwort, Stellaria minor, I noticed a tiny grub, possibly a Lepidopteran caterpillar (?) on the left-hand flower.


Crossing Poor's Meadow I saw that the farmer had started to cut the grass for hay, as is the tradition. The meadow is not particularly flower rich, but may contain some Dyers Greenweed on the southern wooded margin according to the BSBI visit report.


As well as keeping the field traditionally managed, the farmer has also, by accident or design, left the broken down old oak tree as a dead wood habitat.



After Poor's Meadow I crossed the wheat crop, which was ripening well, on the clay field which contains the Shepherds Needle Scandix pecten-veneris,


Moving on to the gravel pits themselves, there was a very nice patch of Hare's-foot Clover, Trifolium arvense, on the gravelly patch down at the southern end of the causeway across the west gravel pit. This plant is locally common in the Southeast of England, particularly at coastal sites and almost always on sandy soils. I am sure this particular patch has been here for several years, annually regenerating itself from the seed, which has effective dormancy mechanisms.

These are the woolly pink inflorescences that are the most obvious sign of the plant's presence - the leaves are fairly insignificant by comparison.


Here is a close-up of a single inflorescence - you can see the tiny whitish flowers in amongst the purple hairs of the calyces, each in turn fringed with a light pink fuzz, most easily seen in outline on the side of the inflorescence.


This is an older inflorescence in the centre, with the flowers browning from the base of the inflorescence upwards. On the left-hand inflorescence. a single white "pea-family" flower is absolutely fully open.


This may be a better close-up of a fading inflorescence specifically to show the hairs arising the calyx in the centre and the fuzz on the side of the inflorescence.


These are the narrow, grey, somewhat hairy (the hairs are adpressed) trifoliate leaves, with the two pointed reddish somewhat filiform stipules.


The plant keys out on the BSBI crib sheet for the genus, http://www.bsbi.org.uk/Trifolium_Crib.pdf. It is potentially a very important plant - it apparently contains a gene affecting tannin condensation that if successfully transferred into white clover could both increase yield and also reduce both bloat and methane emissions from cattle. This is due to be commercially available in about 2025, if it comes to market.

Another plant I found, in good numbers along the paths around the gravel pits, was the Common Birds-Foot Trefoil, Lotus corniculatus, in the pictures below possibly the cultivated variety cv. sativus. This variety, often used in wild flower seed mixes differs from the normal wild plant in having a hollow stem, being more generally yellow, and is also larger and more robust than the native wild form. When I cut the stem of this plant across it was clearly hollow, so my thinking is that it should be cv. sativus. I also checked the key species-characteristic feature, that the sepals were forward pointing, and not reflexed in the bud stage as in the Greater Birds-Foot Trefoil, Lotus pedunculatus.


In the picture below you can see the suffusion of orange in the petals at bud stage, the way the developing pod pushes the brown remnants of the corolla forward as the pod ripens and lengthens, and the generally forward pointing nature of the sepals.


I do keep on looking for the Greater Birds-Foot Trefoil, Lotus pedunculatus, but never seem to find it. This is known to be a similar robust plant which also has a hollow stem, but should be easily distinguished from corniculatus, whether sativus or not, by the reflexed sepals in the bud, no suffusions of red in the petals, and more than 5 (7) flowers in one inflorescence.

Another plant I was very glad to see today was the Common Centaury, Centaurium erythraea, which is only just starting its proper summer-long flowering season.  The flowers are a lovely pink, held on square stalks (both the pedicels and peduncles are square I think).


Part-way along the causeway I had come across a Long-Winged Conehead nymph, Conocephalus discolor, green with a dark stripe down its dorsum. I hadn't come across this insect before, and in its nymphal stages it is certainly a striking animal.



On the brambles in the hedge-line between the two western gravel pits there was what looked like an adult male (no oviposter) Dark Bush-Cricket, Pholidoptera grisoaptera, with its vestigial wings. I used this great site to try to compare the species. http://www.orthoptera.org.uk/account.aspx?ID=13 but I could not see the underside, which should have been yellow.





This is the first time I have seen the Azure Damselfly, Coenagrion puella, down here at Whetsted Gravel Pits - so I shall have to check the so-called "Common Blues" far more carefully in future. As this was also in the brambles by the big hedge between the gravel pits it may have come out of the small ditch there, as opposed to the Common Blues coming out of the main gravel pits themselves. I still believe the vast majority of the blue damsels seen on this site and around it to be the latter species.


For comparison, here is a Common Blue Damselfly, Enallagma cyathigerum, seen earlier, slightly tangled in some silky fibres, sitting quite quietly on the top of a fencepost along the causeway.



One of the nastiest insects around is the Horse Fly or Cleg, Haemotopota (pluvialis perhaps) with its vicious bite. There was one on the causeway which I admired before I fully realised its identity.




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