Stubble field annual wild flowers

 Some common annual wild flowers that flourish along field margins, in the few weeks between a cereal crop harvest and the arrival of the plough.

Common poppy, rejuvenated by warm sunshine, after the very wet weather during this summer's harvest in Teesdale

The tiny, pale blue flowers of field forget-me-not. Many  arable weeds have small flowers but are well worth a closer look.

Scarlet pimpernel has a long flowering period that often extends until the end of October. The flowers always close in mid-afternoon, unless rain clouds cover the sun, when they close quickly to protect their pollen -  behaviour that has earned the plant the reputation as 'the poor man's weather glass'.

Field pansy, a tiny but beautiful flower that has contributed to the parentage of garden pansy

Sky-blue flowers of common field speedwell, a native of the Caucasus that was first recorded in the wild in England in 1826 and has since spread throughout Britain. Like many arable weeds, its seeds are transported far and wide in mud on shoes, hooves and agricultural vehicle wheels. 

Common cudweed, with silvery leaves and tiny yellow flowers.

Common sowthistle whose light seeds, supported by a parachute of hairs, are carried long distances on the breeze

A Blue Scarlet Pimpernel

Nearly forty years ago, when I worked in the Agricultural Research Service, I visited a farm in Shropshire where I noticed the blue form of scarlet pimpernel Anagallis arvensis ssp. foemina growing in a field of onions, alongside the typical scarlet form. This beautiful blue variant is rather uncommon and restricted to central and southern England, so I never encountered it again when I moved to north-east England - until now. Last year I was given some seeds of A. arvensis ssp. foemina and this year they've flowered in our garden. The gentian-blue flowers are as exquisite as I remember them from that first encounter.

The scarlet form already grows in our garden. The plant is also known as poor-man's-weather-glass as the flowers close quickly when the sun is obscured by cloud - so they've been closed rather a lot this summer. They also close entirely in mid-afternoon every day, as regular as clockwork.

The other curious feature of these plants is their spherical seed capsule, known botanically as a pixidium, that opens by splitting around its circumference - click here to see one in action.

Magic of the Hemispheres

Remember those rotating globes of the world that used to be in every school classroom? I recall having a miniature version given to me as a Christmas present by parents who probably hoped it would sharpen up my performance in geography classes. The globe separated around its equator into two hemispheres, just like this scarlet pimpernel Anagallis arvensis seed capsule, which separates and releases a shower of seeds from within it you gently squeeze it. For the plant in flower, see http://cabinetofcuriosities-greenfingers.blogspot.com/search/label/Anagallis%20arvensis)

Botanically, this form of capsule is called a pyxidium - useful to remember if you've got an x to get rid of in a game of scrabble. Plantains (Plantago spp.) have a similar arrangement in their rows of minute capsules, although they're smaller and less aesthetically pleasing.

3 o'clock Closing Time

This scarlet pimpernel Anagallis arvensis plant was growing on the edge of some fields on the seashore at Low Newton in Northumberland. You can use this plant as a rough-and-ready clock because its flowers, which exhibit natural rhythmic sleep movements, always close up at around 3pm. in the afternoon (I took this photo at about 1pm.). It isn’t a very reliable time-piece though, as the flowers also tend to close if the sun clouds over and it begins to rain, so it’s a fair-weather clock. Quite a few plants have these natural flower closure mechanisms at different times of day – most notably Jack-go-to-bed-at-noon Tragopogon pratensis.In 1822 John Claudius Loudon, in his Encyclopedia of Gardening, listed 25 plant species with different flower closure times and suggested that they could be planted as a floral sun dial - which would be colourful but erratic.