Inner beauty of a successful weed

Hedgerows are full of young goosegrass Galium aparine plants at the moment, whose rapid growth has been encouraged by mild winter temperatures. 

This is one of our most successful and ubiquitous weeds, beautifully adapted to fast growth, prolific seed production and efficient seed dispersal.

The seeds, which are covered in tiny hooks and are dispersed in the fur and feathers of animals, germinate in late autumn and early winter so that by spring the young plants have a head start on surrounding vegetation and begin to flower quickly.


The stems elongate very quickly too and the plant is finely adapted to using surrounding plants for support, thanks to ....



... a covering of tiny, backward-facing hooks on the stems and leaves, seen here under the microscope. In fertile agricultural soils the plant can thread its way through a hedge by early summer, sometimes reaching a length of six feet or more and smothering the hedge by the end of summer, all the while producing thousands of hooked seeds from tiny white flowers that are visited by small insects but probably self-pollinate too.

One reason why goosegrass is such a prolific seed producer is that its habit of scrambling over other plants, using those hooks, means that it doesn't need to invest much energy to producing a strong stem. It takes a hawthorn several years to reach a height of six feet, building stem strength through woody tissue production, but goosegrass can reach the same height in about three months.



 This image shows a one cell-thick section through a stem and those yellow stained cells, in a ring in the centre, are the only ones that have any woody strengthening in their cell walls - all the blue-stained cells are pure cellulose. 

The narrow line of yellow staining on the outside of the stem is the waxy cuticle, that protects the plant from water loss.

Just waiting to get their hooks into you ...

Hooked fruits of six British wild flowers, that you might find attached to your trousers after a country walk in autumn. How many can you identify? Answers at the bottom.

A. Fruits about 2.5 cm. in diameter. Common on woodland edges and waste ground.

B. fruits about 5mm. long. In hedgerows and grassland, often on calcareous soils.

C. Fruits about 3mm. long. A woodland herb.

D. Fruits about 3mm. in diameter. A major agricultural weed, common in hedgerows.

E. Fruits about 8-10mm. A common weed of waste places, often found on woodland edges.

F. Fruits about 3mm. A woodland herb.


















Answers:
A. Burdock Actium lappa.
B. Agrimony Agromonia eupatoria
C. Enchanter's nightshade Circaea lutetiana
D. Gooosegrass aka cleavers aka sticky Jack Galium aparine
E. Herb bennet aka wood avens Geum urbanum
F. Sanicle Sanicula europaea

Plants to Stuff a Mattress with.....

In the past - as their name suggests - some bedstraw species have been used for stuffing mattresses because they have pliable stems and make fragrant hay when dried. You would need to spend quite a long time collecting enough of this little ground-hugging species - heath bedstraw Galium saxatile  - to stuff a pillow, let alone a mattress. Up here in the North East heath bedstraw is quite common on dry, acid soils - this specimen was growing on bare ground in a felled pine plantation in the Derwent valley.

All bedstraws have stems with a square cross-section and tiny flowers in the form of a simple cross. This one is - appropriately - crosswort Cruciata laevipes (which was known as Galium cruciata when I was a botany student).

Crosswort has a long flowering period, from spring into summer and ..

... is robust enough to compete with grasses, often forming large stands on grass verges

Woodruff Galium odoratum has a particularly sweet scent of new-mown hay when it's dried (when it also turns black) and, around here at least, is the commonest woodland bedstraw. The other common feature of this family is that they all have their leaves arranged in whorls around the stem - and the leaves are especially large in this species.

The commonest bedstraw - cleavers aka goosegrass aka sticky Jack aka Galium aparine - is a persistent weed whose hooked hairs stick it to clothing, making it a favourite weapon for kids who like to throw handfuls of the plant at each other (at least they did in my day, maybe they do it electronically on a Playstation today). I've found this a handy plant for clearing my pond of duckweed, by dragging handfuls across the surface of the pond - it works a treat. I thought that this was my discovery but apparently handfuls of the plant have long been used as a crude filter for liquids - the Greek botanist Dioscorides (40-90 AD) got there before me and described how it could be used for straining milk.

The stem, seen in cross-section under the microscope, is also surprisingly beautiful.

Hedge bedstraw Galium mollugo, is another robust species....

.... that grows well over 50cm. tall and enlivens grassy places with masses of tiny flowers in late June and early July.

And finally, lady's bedstraw Galium verum which contains large amounts of coumarin and so has a powerful scent of new-mown hay when dried. The flowers have a honey-like scent. There have been attempts to cultivate this plant for the red dye produced by its roots, as a substitute for madder (which is also in the bedstraw family) and there are accounts of its flowers being used as an early source of yellow dye for colouring Cheshire cheese, adding sweetness to the flavour, although annatto from the tropical plant Bixa orellana replaced it. Apparent, the bones of pigs and chickens fed on lady's bedstraw turn red, which could add an interesting splash of colour to the Sunday roast.

Although bedstraws were used for stuffing mattresses (myth has it that lady's bedstraw, formerly known as Our Lady's Bedstraw, was used to stuff the Virgin Mary's bed, and Henry VIII is said to have enjoyed sleeping on a hay-filled mattress) it has been suggested that the 'straw' part of the name is a corruption of the word 'strow' and that the commonest use of this fragrant plant was as a strewing herb on floors. John Gerard describes how woodruff "being made up into garlandes and bundles, hanging up in houses in the heat of summer, doth very well attemper the aire, coole and make fresh the place, to the delight and comfort of such as are therein". More recently, in Victorian and Edwardian times, lady's laid the dried plant in the bottom of their drawers, to impart a sweet odour to stored clothes and to deter moths.