A really great Forestry Commission site in deepest Denbighshire, even if I didn't hear the hoped for wood warblers and Redstarts on my late morning visit today! This is one of the fine parts of the huge Glocaenog Forest.
This Cheilosia on Creeping Buttercup, Ranunculus repens, really ought to be the albitarsis/ranunculi group. The first thing to note is that this insect is a male with a blue-black thorax and slightly darkened wings, and generally dark legs:
This picture shows what appears to be a fairly dense covering of pale hairs on the eyes
Moving on to the more botanical side of things, the Cheilosia above is feeding on a Creeping Buttercup flower, Ranunculus repens (L.).
The Creeping Buttercup is a herbaceous, stoloniferous perennial growing to 50 cm tall. There are many named subspecies. It has both prostrate running stems, which produce roots and new plants at the nodes, and more or less erect flowering stems arising from a short stout "caudex" with a rosette of leaves. The basal leaves are divided into three broad normally stalked leaflets 1.5–8 cm long, shallowly to deeply lobed, borne on a 4–20 cm long petiole; leaves higher on the stems are smaller, with narrower leaflets. The leaves may be white-spotted. Both the stems and the leaves are finely hairy. The flowers are bright golden yellow, 2–3 cm diameter, usually with five petals. The nectaries are easily seen as tiny pockets at the base of the petals. The fruit is a cluster of achenes 2.5–4 mm long. It grows in fields, pastures, woods, gardens, parks, roadsides and wasteland and prefers wet soil.
Useful ID points are the spreading (not reflexed) sepals, the grooved stems and the stalked (petiolulate) terminal lobe of the trifoliate leaves. Interestingly there have been no reports of a mycorrhizal association.
Like most buttercups, Ranunculus repens is poisonous, although when dried with hay these poisons are lost. The toxin protoanemonin (apparently a break-down product of ranunculin) is not very stable and loses its potency when dry, so buttercup is not generally toxic in hay. The taste of buttercups is acrid, so cattle generally avoid eating them. The plants then take advantage of the cropped ground around it to spread their stolons.
Creeping buttercup spreads by seed and by long branching stolons that root at the nodes, forming new plants (ramets). The stolons may also regrow from cut portions to some extent. In more established woodland and grassland communities, this plant increases mostly through stolons unless the soil is disturbed. In dry conditions, flowering and seeding is more prevalent and in wet conditions, stolons are more plentiful. Seeds can germinate and seedlings can grow even under water-logged conditions. The plant is also said to be spread through the transportation of hay, implying that the seed may be present, I would imagine!
The plant is a serious invasive weed in places like North America and New Zealand. Here is a link to a useful Canadian paper on the biology of this minor threat to their ecosystems and agriculture. http://pubs.aic.ca/doi/pdf/10.4141/cjps90-135
One of the reasons creeping buttercup is so competitive is that its stolons respond to the environment. Under favourable conditions, plants form more stolons through branching. However, when nitrogen or water is limiting, stolons tend to be longer and un-branched allowing longer distance “sampling” of a number of potential sites until more suitable locations are found. When favourable conditions are discovered, stolon branching resumes, allowing rapid local colonization to take advantage of the available resources. In general, short stolons are produced in dense turf and much longer ones appear in open fields or woodlands.
Depending on the temperature, creeping buttercup either overwinters as a rosette or dies back to ground level. In either case, the nutrients stored in the short swollen stem produce rapid growth in spring, between April and June. Stolons grow from the leaf axils in spring and summer and growth peaks in late summer. Stolons connecting parent and daughter plants usually die off in autumn, leaving the plantlets separate.
Flowers can appear from March to August with seeds soon after. Each plant produces from about 20 to 150 (this may be an over estimate) seeds. Seeds can remain viable in the soil for at least 20 years, and up to 80 years, especially under acid or water-logged conditions. Seeds are dispersed by wind, water, birds, farm animals, rodents, and other animals by adhering to them with the hooked seeds. They exhibit dormancy and also sustained viability in the seedbank.
Excessive contact with the sap of the plant can cause skin blistering in humans, and various toxic effects in cattle if they eat it in excess because they there is little else and they are hungry. Unfortunately, livestock occasionally develop a taste for buttercup and consume fatal quantities.
The age of meadows up to 200 years old can be roughly estimated by the number of plants in 100 that have extra petals in their flowers - you get about 1 plant with flowers with extra petals for every 7 years old it is claimed. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2729631/ Mentioned in notes of nature. However the correlation coefficient is only moderate, in my view. This flower, photographed by chance a little further along the woodland path at Bod Petrual, turned out on closer examination to have 8 petals as far as I can see! I can just see 1 of the 3 sepals below I think.
and this one has 6 petals.
This on the other hand is another toxic plant, the Meadow Buttercup, Ranunculus acris, with a more finely dissected basal leaf. In this species there tend to be 5 (3 - 7) leaflets and in addition, unlike in the Creeping Buttercup, the middle (or each?) leaflet is un-stalked, giving a typical palmate rather than trifoliate appearance. The BSBI plant crib is very useful here: http://www.bsbi.org.uk/Ranunculus_Ranunculus_Crib.pdf
There is a photo below that of the characteristically even more dissected stem leaf. There were several scattered plants, in amongst or separated from the Creeping Buttercup, apparently it appears at random. There were very many fewer of this species, and I didn't happen to see any Cheilosia on them.
The very different, almost linear, un-stalked stem leaves of Ranunculus acris (L.) acris, the only subspecies found in the UK - although there are three different races!
The fairly common confusion species to Ranunculus repens is the Bulbous Buttercup, Ranunculus bulbosus, of drier grasslands, which has sepals that are reflexed in full flower. I saw this behind the dunes at Warkworth last week I believe.
In the Meadow Buttercup, the flower is similar to the flower of the Creeping Buttercup, with un-reflexed (spreading) sepals, but the flower stalk is, by contrast to the Creeping Buttercup, ungrooved. Another feature is the chromosomal number. Ranculus repens is generally a tetraploid plant (N = 32) based on N = 8, while Rancunulus acris is also a tetraploid (N = 28) based on N = 7.
There were plenty of other plants growing in profusion, and a few were even in flower. It was particularly nice to see the Cuckoo Flower, Cardamine pratense, so long after all the ones in Kent are long over.
This Cheilosia on Creeping Buttercup, Ranunculus repens, really ought to be the albitarsis/ranunculi group. The first thing to note is that this insect is a male with a blue-black thorax and slightly darkened wings, and generally dark legs:
This picture shows what appears to be a fairly dense covering of pale hairs on the eyes
Moving on to the more botanical side of things, the Cheilosia above is feeding on a Creeping Buttercup flower, Ranunculus repens (L.).
The Creeping Buttercup is a herbaceous, stoloniferous perennial growing to 50 cm tall. There are many named subspecies. It has both prostrate running stems, which produce roots and new plants at the nodes, and more or less erect flowering stems arising from a short stout "caudex" with a rosette of leaves. The basal leaves are divided into three broad normally stalked leaflets 1.5–8 cm long, shallowly to deeply lobed, borne on a 4–20 cm long petiole; leaves higher on the stems are smaller, with narrower leaflets. The leaves may be white-spotted. Both the stems and the leaves are finely hairy. The flowers are bright golden yellow, 2–3 cm diameter, usually with five petals. The nectaries are easily seen as tiny pockets at the base of the petals. The fruit is a cluster of achenes 2.5–4 mm long. It grows in fields, pastures, woods, gardens, parks, roadsides and wasteland and prefers wet soil.
Useful ID points are the spreading (not reflexed) sepals, the grooved stems and the stalked (petiolulate) terminal lobe of the trifoliate leaves. Interestingly there have been no reports of a mycorrhizal association.
Like most buttercups, Ranunculus repens is poisonous, although when dried with hay these poisons are lost. The toxin protoanemonin (apparently a break-down product of ranunculin) is not very stable and loses its potency when dry, so buttercup is not generally toxic in hay. The taste of buttercups is acrid, so cattle generally avoid eating them. The plants then take advantage of the cropped ground around it to spread their stolons.
Creeping buttercup spreads by seed and by long branching stolons that root at the nodes, forming new plants (ramets). The stolons may also regrow from cut portions to some extent. In more established woodland and grassland communities, this plant increases mostly through stolons unless the soil is disturbed. In dry conditions, flowering and seeding is more prevalent and in wet conditions, stolons are more plentiful. Seeds can germinate and seedlings can grow even under water-logged conditions. The plant is also said to be spread through the transportation of hay, implying that the seed may be present, I would imagine!
The plant is a serious invasive weed in places like North America and New Zealand. Here is a link to a useful Canadian paper on the biology of this minor threat to their ecosystems and agriculture. http://pubs.aic.ca/doi/pdf/10.4141/cjps90-135
One of the reasons creeping buttercup is so competitive is that its stolons respond to the environment. Under favourable conditions, plants form more stolons through branching. However, when nitrogen or water is limiting, stolons tend to be longer and un-branched allowing longer distance “sampling” of a number of potential sites until more suitable locations are found. When favourable conditions are discovered, stolon branching resumes, allowing rapid local colonization to take advantage of the available resources. In general, short stolons are produced in dense turf and much longer ones appear in open fields or woodlands.
Depending on the temperature, creeping buttercup either overwinters as a rosette or dies back to ground level. In either case, the nutrients stored in the short swollen stem produce rapid growth in spring, between April and June. Stolons grow from the leaf axils in spring and summer and growth peaks in late summer. Stolons connecting parent and daughter plants usually die off in autumn, leaving the plantlets separate.
Flowers can appear from March to August with seeds soon after. Each plant produces from about 20 to 150 (this may be an over estimate) seeds. Seeds can remain viable in the soil for at least 20 years, and up to 80 years, especially under acid or water-logged conditions. Seeds are dispersed by wind, water, birds, farm animals, rodents, and other animals by adhering to them with the hooked seeds. They exhibit dormancy and also sustained viability in the seedbank.
Excessive contact with the sap of the plant can cause skin blistering in humans, and various toxic effects in cattle if they eat it in excess because they there is little else and they are hungry. Unfortunately, livestock occasionally develop a taste for buttercup and consume fatal quantities.
The age of meadows up to 200 years old can be roughly estimated by the number of plants in 100 that have extra petals in their flowers - you get about 1 plant with flowers with extra petals for every 7 years old it is claimed. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2729631/ Mentioned in notes of nature. However the correlation coefficient is only moderate, in my view. This flower, photographed by chance a little further along the woodland path at Bod Petrual, turned out on closer examination to have 8 petals as far as I can see! I can just see 1 of the 3 sepals below I think.
and this one has 6 petals.
This on the other hand is another toxic plant, the Meadow Buttercup, Ranunculus acris, with a more finely dissected basal leaf. In this species there tend to be 5 (3 - 7) leaflets and in addition, unlike in the Creeping Buttercup, the middle (or each?) leaflet is un-stalked, giving a typical palmate rather than trifoliate appearance. The BSBI plant crib is very useful here: http://www.bsbi.org.uk/Ranunculus_Ranunculus_Crib.pdf
There is a photo below that of the characteristically even more dissected stem leaf. There were several scattered plants, in amongst or separated from the Creeping Buttercup, apparently it appears at random. There were very many fewer of this species, and I didn't happen to see any Cheilosia on them.
The very different, almost linear, un-stalked stem leaves of Ranunculus acris (L.) acris, the only subspecies found in the UK - although there are three different races!
The fairly common confusion species to Ranunculus repens is the Bulbous Buttercup, Ranunculus bulbosus, of drier grasslands, which has sepals that are reflexed in full flower. I saw this behind the dunes at Warkworth last week I believe.
In the Meadow Buttercup, the flower is similar to the flower of the Creeping Buttercup, with un-reflexed (spreading) sepals, but the flower stalk is, by contrast to the Creeping Buttercup, ungrooved. Another feature is the chromosomal number. Ranculus repens is generally a tetraploid plant (N = 32) based on N = 8, while Rancunulus acris is also a tetraploid (N = 28) based on N = 7.
There were plenty of other plants growing in profusion, and a few were even in flower. It was particularly nice to see the Cuckoo Flower, Cardamine pratense, so long after all the ones in Kent are long over.
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