|Buttercups belong to the genus Ranunculus, and
in this country there are over thirty species in this genus, which
includes the water crowfoots and lesser celandine. It is probably easy
at first glance to think that there is only one species of buttercup,
but there are actually four species which, although they are all noticeably
different, are easy to confuse.
The four species are:
Common or bitter buttercup Ranunculus acris
Bulbous buttercup Ranunculus bulbosus
Creeping buttercup Ranunculus repens
Goldilocks Ranunculus auricomus
|The first three above
usually start flowering at the beginning of May, while goldilocks starts
about a month earlier and is usually found in woodland where it needs
to flower before the trees start to shade it as their leaves break.
The characters to look for with goldilocks are an erect stem bearing
simple three lobed leaves, almost kidney shaped leaves at the base
but dissected ones up the stem. The flowers are bright yellow as in
all the buttercups, but often, though not always, appear as if one
or two are missing from the five you would normally expect. Finally,
look at the seeds because they are hooked a bit.
|The corn buttercup ,
being an annual species growing with cereals, flowers when the corn
is ripening, has small flowers and then large seeds.
|Now the other three.
The common buttercup (Ranunculus acris) is
rather unpalatable to cattle, so it is often left uneaten, they don't like the
taste. The stems are erect, up to 80cm, often with a whitish bloom and branched
to produce an inflorescence of bright yellow flowers, and the leaves are delicately
dissected. Look for two features. The sepals are held up against the petals like
a greenish yellow cup and the flower stalk is round and smooth.
|The bulbous buttercup(Ranunculus
bulbosus), like the common buttercup grows mainly in grassland, and
flowers in the first week in May making fields bright yellow instead
of green because they occur in such huge numbers. It is called bulbous
because the stem is swollen just below ground level, so you can't see
that without pulling the whole plant up. Look for the sepals, which
quickly become reflexed (folded back on themselves) and the flower
stalk which is ridged rather than smooth as in R. acris.
|Thirdly, the creeping
buttercup (Ranunculus repens). As its name suggests it tends
to be a prostrate species, with stems on the ground rooting at the nodes ,
rather than erect as in the two previous species. This varies, depending
upon the nutrient status where it is growing. The
flower stalk is ridged as in R. bulbosus, but the sepals are
not reflexed. It sometimes has more than the five petals one would
expect and the extra ones are often smaller than the others. Look
for trailing stoloniferous stems rooting at the nodes and variously
dissected leaves which have colour variegation at the base of the
dissections of the leaf.
|A fifth species which is now very rare. It is
the Corn Buttercup – (Ranunculus
arvensis). It is an annual which used to grow in cereal crops, and
is rare because farmers do not allow their cereals to become weedy.
It is a slender plant which can grow
up to 60cm if the nutrient status is high and there are tall plants,
like cereals, to compete with. It has small yellow
flowers and is notable for its spiny
seeds . The one pictured has a strange history. When the A127 road
was being widened near Basildon in Essex, one plant appeared on the
road verge where the soil had been disturbed. Seed was collected from
it, multiplied and distributed. I have it growing in a plant pot in
the garden and expect it to flower at the end of May.