A cowslip at Christmas

 

These cowslips have been flowering in my garden since mid-December. This particular plant often flowers in late winter, but I can’t recall ever seeing cowslips in full bloom at Christmas. This unseasonal behaviour is likely a response climate disruption, to the plant recovering from summer drought and then producing rapid new growth in autumnal daylengths that would be similar to those that initiate flowering in spring. Since then, mild weather with few frosts and only one day of light snow have encouraged it to bloom.

Autumn seed dispensers - beautifully functional natural architecture

 Seeds' pods and capsules are remarkable examples of beautiful, functional natural architecture. The two photographs below show what happens when seed pods of American willowherb Epilobium ciliatum are ripe. The pod splits longitudinally into four sections that gradually curl backways, dragging with them the hairy 'parachute' plumes of the rows of seeds, which eventually break free and are carried away on the wind. 

Mouse-ear chickweed carries its seeds inside a translucent, flask-shaped capsule which has a ring of teeth around the opening. The teeth respond to changes in surrounding moisture, opening to release seeds when they dry out.

Cowslip seed capsules (below) also open via a ring of teeth that curl backwards in dry air. These capsules are still full of seeds which, after shedding, will usually remain dormant in the soil until spring, needing the low temperatures of winter to break their dormancy.

New Year Plant Hunt in and around Durham city today

A second day of New Year Plant Hunting, this time along the banks of the river Wear and along woodland edges and hedges. Nineteen species in flower this time, of which these are some of the most pleasing:

Alder catkins

Hazel catkins

Hogweed

Nipplewort Lapsana communis

Lesser celandine, flower petals eaten by a slug but very attractive variegated foliage.

...... and cowslip, flowering four months early.

The cowslip was on the Durham University estate, on the Mountjoy site, about 400 metres from an area that was seeded with wild cowslips about 20 years ago. Since then they save seeded themselves on various places, most likely with seed carried on feet of staff and students. This single flowering plant was amongst a population of over 50 non-bloomers, all with very vigorous new leaf growth, on a very sheltered grassy bank under an alder.

Primslips or Cowroses?

The wild flower conservation charity Plantlife is conducting a poll to find Britain's favourite wild flower and the primrose Primula vulgaris is a strong contender to take the title. Currently it is in top position in Scotland and Wales, second in England and third in Northern Ireland.

Primrose is primarily a plant of woodland edges, glades and hedgebanks, growing best in dappled shade and in moist soils. It's also a very variable plant, thanks to its breeding system, where there are two forms of flower - pin-eyed and thrum-eyed - with the stamens and stigma arranged in a way that ensures cross pollination when insects travel from plant to plant. 

Pin-eyed flowers have their stigma at the top of the floral tube and their stamens lower down, whereas ...

... thrum-eyed flowers have stamens at the top, with the stigma hidden underneath them.  It's an arrangement that maximises the chances of cross-pollination, reinfornced with an incompatibility system where the flower's own pollen will not normally germinate on its own stigma. The cross-pollination that this enforces generates genetic variability within the population - compare the broad-petalled flower above with ....

.. this one which has much narrower petals.

Primrose also readily crosses with .....

....... cowslip Primula veris wherever the two species meet, typically where woodlands meet the pastures that are the favoured habitats of cowslips. 

Populations of false oxlips, the natural hybrid between the two species, show almost every grade of intermediate form between pure cowslip and pure primrose..... with what you might call primslips and cowroses in between!

Cowslips typically have these small, intense yellow, downward-pointing flowers whereas .... 

..... false oxlip flowers tend to point outwards or even upwards and are larger and paler coloured. The false oxlip - with an injection of genes from a cross with at least one other more colourful European species ....

....... is the ancestor of the gaudy, very popular polyanthus that is the mainstay of so many municipal bedding schemes in spring.

Newly minted butterfly.....

We found this newly-emerged green-veined white, still 'pumping up' its hind wings, when we walked along the sea cliffs south of Seaham this morning.

This early purple orchid - the first I've seen this year - was flowering in the meadows near Hawthorn Dene and was already past its best. Spring flowers are enjoying a very short season this year, having been held back for so long............... 

........... but the display of cowslips in the same meadow is magnificent. We also saw ....

............ a few false oxlips, which are the natural hybrid between primroses and cowslips.

Down on Blast beach, at the base of the cliffs, landslips have created sheltered, steep banks at the top of the beach that are carpeted in primroses.




The finest floral display, though, is at the top of the cliffs, where the gorse is in full bloom, with its wonderful coconut aroma and .....




...flowers that are so closely packed together that they completely hide the bushes

Primslips and Cowroses

The old railway line between Romaldkirk and Cotherstone in Teesdale is now a very attractive public footpath (with a convenient pub at either end) and this year there are spectacular displays of ....

...primroses Primula vulgaris in the woodland that has developed on the embankments and ....

... cowslips Primula veris  in the grass in the pastures and more open areas, and wherever these two habitats coincide there are ....

...... magnificent specimens of false oxlips, the natural hybrid between the two species. Every wild flower guide describes primroses and cowslips as separate, distinct species but no one told the plants, or the insects that cross pollinate them in spring. The hybrids tend to have the large individual flowers of primroses mounted on the tall stems of cowslips and are often very floriferous, displaying hybrid vigour. False oxlips have been grown in gardens since at least Elizabethan times and are the ancestors of the garden polyanthus, that has also received an injection of floral pigment genes from another European primrose species at some point in its history. Almost every false oxlip plant is subtly distinct because they can also backcross to either parent, so every conceivable intermediate form is there in the population. Along this railway line enbankment there's also just one ....

..... pink-flowered primrose, that must be the result of a cross with a cultivated Primula species. The bumblebee - slightly to the right and above centre in the picture - was busy disseminating this coloured variant's genes amongst the surronding plants in the population.

Spring Wild Flowers in Weardale

Last autumn I posted some pictures of a walk up through Slitt Woods in Weardale, following the course of Middlehope Burn upstream. These pictures were taken this weekend, following the same route, starting with masses of sloe blossom in the woodland, attracting the attention of this green-veined white butterfly.

All through the woodland there's a fine display of primroses and around the hazels ...

.....these flowers of toothwort, which is a parasite on hazel roots, are in bloom.

The mountain pansies are just coming into flower in the grassland on the moorland edge. There are numerous colour variations.

Sedges thrive in the short, sheep-grazed turf. The yellow 'paintbrush' is the male flower, composed of numerous stamens, and the white feathery stigmas of the female flowers can be see further down the stem

The ruins of the old lead mine buildings form a natural rock garden for dog violets. 

Field woodrush, growing in the short turf.

The early purple orchids at the top of the woodland are earlier than ever this year, thanks to the warm, dry weather.

Marsh marigold thrives around the old lead washing floors, where lead was separated from crushed rock using the force of flowing water. The parabolic flowers of marsh marigold focus the sun's rays and the temperature inside the flower is always a few degrees higher than outside, making them a popular resting place for sun-basking flies.

Up in the edge of the high pastures cowslips are in bloom.

Life on the Edge

The Durham coast used to be famed for industrial dereliction and coal waste dumping, but thanks to a wonderfully successful clean-up campaign it's now a great place for coastal walking, where you can get eye-to-eye with a kestrel as it glides on the updraft from the beach.

The cliffs south of Seaham are becoming popular with birders  - it's a great place to watch the fulmars that nest on the cliffs as they glide by .... 

... and yesterday the scrub on the cliff top was alive with singing whitethroats

...

... along with this smartly turned-out cock chaffinch..

The calcareous grassland along the Durham Coastal path is now part of the Durham Heritage Coast and just now the cowslips are coming into full bloom ...

.... along with the early purple orchids - a narrow strip of floral diversity, perched on top of the crumbling cliff edge