It’s closer to home for my next blog, my monthly trip to Raisby Hill. What a difference a month makes! The first meadow I walk through is still a mass of Cowslips and Water avens but now there are pink and purple orchid spikes amongst them – mostly Heath-spotted and Northern marsh-orchids, I think, though it is not always easy to tell and I know they hybridise…
In theory, at least, the Heath-spotted orchid, Dactylorhiza maculata, can be distinguished from its relatives by its conical, becoming cylindrical, flower spikes and the fact that its lip is only slightly lobed, with the central lobe shorter and narrower than the side lobes. This lip is covered in streak- and loop-like markings. The Northern marsh-orchid, D. purpurella, as its name suggests, has a somewhat shorter spike of deep purple flowers covered in crimson streaks and this time the middle lobe of the lip is longer than the side ones. Both species are largely pollinated by bumblebees but don’t provide a nectar reward for the bees – instead they rely on the their conspicuously-coloured flowers to attract pollinators.
Left: Dactylorhiza maculata, Right, D. purpurella
These orchids are easy to spot from a distance but the third type I find when I have a wander round the meadow is Common twayblade, Neottia ovata, with its much less conspicuous flowers. Their names come from the large pair of egg-shaped basal leaves which are often much easier to spot than the green flower spikes. Neottia are one of the most common European orchids, partly because they are fairly promiscuous in their relationships with both pollinators and the mycorrhizal fungi necessary to support germination and seedling growth (Jacquemyn et al., 2015).
The flowers are pollinated by parasitic wasps, sawflies and beetles. A wide range of species can collect the pollinia, which lie free on top of the rostellum. When an insect touches the rostellum, the pollinia are glued to its body by a sticky liquid ejected from the rostellum and can then be transferred between flowers.
Orchids have really tiny, dust-like seeds without the endosperm on which a developing seedling normally depends, so most rely on a fungal partner to supply water and nutrients from the earliest stages of growth.
In contrast, the Water avens in the meadow produce large achenes when they set seed, with long hooks derived from the remains of the style. These aid dispersal when they catch in animal fur or feathers. These plants spread themselves around in more ways than one, though – Water and wood avens (Geum rivale and G. urbanum) hybridise freely to produce a range of intermediates called G. x intermedium which often have yellow petals but the drooping growth form of Water avens.
Geum rivale flower and fruit, G. urbanum and G. x intermedium
Climbing up the hill from the meadow to the drier slopes above I find my fourth orchid of the day, the Common-spotted, Dactylorhiza fuchsii but, more excitingly, my first wild Columbines. These statuesque plants look far too showy to be wild flowers and it’s a surprise to find that they are members of the buttercup family but they are one of the things for which Raisby Hill grassland has SSSI status.
Left, Dactylorhiza fuchsii; right, Aquilegia vulgaris
The scree slopes are now transformed with a yellow haze of Bird’s-foot trefoil, Hawkweeds and Rock roses, amidst the scrubby willow now shedding its fluffy seeds.
There are occasional blue or purple patches of Milkwort or Wild thyme and some white Bladder campion.
Left; Milkwort, Polygala vulgaris: Right; Wild thyme, Thymus polytrichus
Around the quarry itself I find my first spiny Burnet rose of the year amongst the violets still in flower and in the woods the Arum maculatum which was so dominant last month has all but disappeared; it will no doubt become visible again, when its berries turn scarlet. The Hawthorn hedges are finally in bloom (rather late for ‘May’ blossom!).
Walking back alongside the fen area I noticed the damp areas are quickly being colonised by Creeping buttercups – a feast for the eyes. Intriguingly, the Milkwort on this side of the beck is lilac coloured rather than blue.
Here is the list of plants in flower for June, with the usual proviso that it’s far from complete, especially with respect to grasses and sedges!
|Meadow buttercup||Ranunculus acris|
|Creeping buttercup||Ranunculus repens|
|Common mouse-ear||Cerastium fontanum|
|Bladder campion||Silene vulgaris|
|Common rock-rose||Helianthemum nummularium|
|Common dog-violet||Viola riviniana|
|Lady’s mantle||Alchemilla vulgaris agg.|
|Wild strawberry||Fragaria vesca|
|Water x wood avens hybrid||Geum x intermedium|
|Water avens||Geum rivale|
|Wood avens||Geum urbanum|
|Burnet rose||Rosa spinosissima|
|Bramble||Rubus fruticosus agg.|
|Salad burnet||Sanguisorba minor ssp. minor|
|Meadow vetchling||Lathyrus pratensis|
|Black medick||Medicago lupulina|
|Red clover||Trifolium pratense|
|Common vetch||Vicia sativa|
|Bush vetch||Vicia sepium|
|Common milkwort||Polygala vulgaris|
|Cow parsley||Anthriscus sylvestris|
|White dead-nettle||Lamium album|
|Wild thyme||Thymus polytrichus|
|Ribwort plantain||Plantago lanceolata|
|Germander speedwell||Veronica chamaedrys|
|Heath speedwell||Veronica officinalis|
|Common daisy||Bellis perennis|
|Oxeye daisy||Leucanthemum vulgare|
|Mouse-ear hawkweed||Pilosella officinarum|
|Common spotted-orchid||Dactylorhiza fuchsii|
|Heath spotted-orchid||Dactylorhiza maculata|
|Northern marsh-orchid||Dactylorhiza purpurella|
|Common twayblade||Neottia ovata|
|Quaking grass||Briza maxima|
|Crested dog’s-tail||Cynosurus cristatus|
|Common sedge||Carex nigra|
Jacquemyn, H. et al. (2015). Mycorrhizal diversity, seed germination and long-term changes in population size across nine populations of the terrestrial orchid, Neottia ovata.