Butterbur - Petasites hybridus

From late March Butterbur erupts from the cleared “flower bed” it prepared the previous winter. 

For me, spring has arrived.

The white and pink flower spikes are loved by bumble bee queens just out of winter hibernation. Soon the leaves appear and just keep growing up to a 1m across. They are the largest undivided leaves of any native plant and they smother all other plants around them, so clearing the earth and creating the flower bed for next year’s spring show.

The butterbur is actually a member of the daisy family. It prefers damp roadsides and river banks and is widespread in Linn Park.

The photos are all taken from slope on the path from Linnpark Avenue to River Cart walkway.

Clover

Clovers are a ubiquitous flower of the grass bank and heath, recognisable in white, pink blush, deeper red through to mauve. There are over 20 different clovers in the UK but the main ones we see in Linn are the white and red clover.

Clovers are members of the large pea family (Fabaceae) which includes pea, beans, clovers, vetches as well laburnum, carob, peanuts, liquorice, gorse, broom and lupins. As well as being important as crops they are also important for the wider environment. Most Fabaceae have nodules on the roots that contain millions of Rhizobia bacteria. These take the inert atmospheric nitrogen and convert it into a form that the host can use. This process is called nitrogen fixation and fixed forms of nitrogen are essential for life. Until we starting burning fossil fuels, the main natural sources of fixed nitrogen were these bacterial factories in the roots of the pea family and lightning strikes. Today clovers are still widely used as a green manure where the plants are grown and then ploughed into the soil to improve it.

White clover (Trifolium repens) is a shorter plant than red clover and grows well in mown grass, such as the field of moss I call my lawn. It is wide spread in the meadows around Linn. The flowers start out white but later develop a pinkish tinge then turn brown.

The red clover (Trifolium pratense) prefers longer grass and is often found in the woodland edge. Beside the Linn on the east side upstream of the white bridge there is also Zig-zag clover (Trifolium medium). This looks like red clover, but the flower heads are on longer stalks and a flatter and looser. The leaf like structures at the base of leaf stalks (stipules) do not end in thin hair like projections like they do in red clover. The stem also tends to zig-zag between leaf stalks.

Tall white umbrella-like plants

There are three common members of the umbellifers or carrot family in Linn Park. These are common tall white flowers with small flowers spread on stalks, which spread out like the spokes of an umbrella in a convex or flat heads. There is also the unmistakable Giant Hogweed and Ground Elder in the park, but I want to show these three similar plants.

In order of flowering:

Sweet Cicely Myrrhis odorata is widespread and comes out in May. It has divided leaves which smell of aniseed when crushed. They often have a white mottling at their bases. The creamy flowers become flask shaped brown seeds with ridges and bristles.

Cow Parsley Anthriscus sylvestris comes in flower slightly later and dominates hedgerows from mid-May through June. The ridged hollow stems are hairy at the base and the leaves are more finely divided and the flowers are more spaced than Myrrhis. The fruits are black narrow and egg shaped.

Hogweed Heracleum sphondylium flowers in July through to September. It is a taller and coarser flower than the other two. The leaves are only divided once into broad toothed leaves and sheath the hollow stems at their base. The flowers are pale pink and the umbel tends to be flatter. The clustered seeds are flat, round and pale.

These stems are important for overwintering insects especially solitary bees.

 

Field Horsetails - Equisetum Arvense

Horsetails are a plant of waste ground and disturbed land. Known also as the Lego plant, because its stems are in segments and can be reassembled after being pulled apart, It is a persistent weed due to this segmental growth as it extends to the deep roots. If gardeners leave one part, it will re-grow. However in recompense, an infusion of boiled horsetails is reported to be an effective fungicide for rose mildew.

In March and April it has un-branched stems with a cone on top. They look a bit like brown sticks of asparagus.

It has a lot of crystals of silica in the leaves and stems, which makes it unpalatable to grazing animals but useful for scouring pans and finishing off brass work.

Equisetum is a "living fossil" as it is the only living genus of a much larger family. One hundred million years they were much more diverse and dominated late Paleozoic forests and they formed much of our coal and oil.

So as a gardeners are cursing their persistence they are also responsible for a lot of the carbon we are pouring into our environment.

Notes about how to get rid of them in your garden:

  • Increasing the lime content will discourage them. They are very uncommon in most of the SE due to chalk. That is the only way the hatted Botanist knows how to reduce their vigour.
  • And digging them up is as difficult as Dandelions as they have the same long root.

Indian Balsam - Impatiens Glandulifera

Spread of Indian BalsamThis is widespread in Linn Park and growing up to 3 metres tall with stems up to 3 cms wide, it is not easily missed. It was introduced from the Himalayas in 1839 and quickly spread up rivers from the West Country until it became a problem alien invader. Its spread from 1900 to 1970 is shown here:

It has attracted many names, Himalayan Balsam, Policeman’s Helmet and Bee-Bums. The latter name is easy to understand on a summer day you can watch bumblebees disappearing into the flower often with only their tails showing. 

The bees are attracted by the generous amounts of nectar that it produces and as the bees enter the flower they are covered in pollen from the conveniently placed anthers. When the plant has given up enough pollen the anthers detach and the female style becomes receptive to pollen carried in by the bees from a different plant.

Later on when the seedpods have developed they can be “popped” and as the pod explodes under its own tension it can fire the seeds many metres. This accounts for the plants success in spreading along the river banks as the seeds are carried downstream. The mechanism is simply that the outside of the pod wants to be shorter than the inside and so grows under tension. When it ripens the pod cracks open and the capsule segments rapidly roll back and expel the seeds. 

Balsam is an annual plant indeed it is the tallest annual wild flower in Britain. So these seeds are essential for next year’s crop of plants. The seeds require a period of cool weather and favour disturbed ground or bare earth to germinate so the winter floods scouring the banks prepare the ground as well as bringing the seeds. It is sensitive to frost and doesn't grow on land above 250m which is surprising with its alternative name of Himalayan Balsam.

Many people confuse it with Japanese Knotweed another alien invader, which also favours river banks. It is also tall but doesn't have these glorious pink flowers and is perennial.

Remarkable how this plant operates.

See the Exploding Seeds - amazing what hydraulic [??] power can achieve !

That seems to be wrong ! The seed grows within the stamen, and then outgrows it ... causing tension in the stamen which tension exceeds its strength causing it to burst - Thanks to a forester from Pollok Park for the explanation !

For more on this remarkable plant, please see this article, from which the map of the spread has been taken.

Common Knapweed - Centaurea nigra

This is a common perennial weed of the grassland, hedgerows and wastelands. Its Scots name is “Hardheads” which refers to the hard globe overlapping bracts below the purple florets. One distinctive feature is the swelling of the stem just below the flower.

It can be confused with a thistle, but there are no spines and the leaves are soft. It is an important flower for bumblebees, goldfinches and many butterflies.

Orchids

Common Spotted Orchid (Dactylorhiza fuchsia) is the only member of this group of orchids that grows in Linn. It is distinguished from the Heath Spotted Orchid (D. maculate) mainly by the shape of the labellum – the lower lip to the flower. You will see that the one in Linn has 3 clear lobes whereas the Health Spotted Orchid has a ruffled edge to a labellum without clear lobes. There are other differences and it is further complicated because they hybridise frequently.

Next time you are passing have a close look at the flower. Although common they are protected and you cannot pick them. Behind the flower you will see the spur pointing downwards. The nectar occurs all the way down that spur and so the insects that pollinate these flowers have to have a long tongue. Look at the “stalk” where the flower attaches itself to the spike of flowers and you will see it is twisted. Like most orchids, as they come out from bud they twist through 180° and so the flowers we see are upside down.

The name orchid comes from the supposed similarity of the tuber to a testicle (Latin orchis). This family has tubers that are divided up like fingers (please don’t dig up to check). The orchid family have microscopic seeds and they require a supportive (symbiotic) relationship with fungi to survive and flourish. These tubers are a store of food and maintain this essential relationship with the soil fungi.

Purple Toadflax - Linaria purpurea

This grows on the wall in Netherlee Road overlooking the field. It is originally from Italy and is very common in the South of England but is a garden escape in Scotland.

Ragged Robin - Lychnis Flos-cuculi

This is a flower of damp meadows that can be found in Linn Park close to the edge of the woods on east of the Park. It is a lovely delicate pink flower with each of the fine petals deeply divided into 4 parts. It is similar to Red Campion but is a more delicate and finer plant. It is common across the UK but is declining as suitable habitats are drained.

Its common name is a delightful description, but its Latin translates as Cuckoo Flower which is a common name for a completely different species.

Silverweed - Potentilla anserine

This grows on paths, beaches and in grass throughout the park. It has silky green above and matt grey below with glorious yellow flowers in summer.

It was known as Travellers Joy because the leaves reputedly relieved tired feet if stuffed in shoes. The roots can be dried and ground into a rough flour. They taste like parsnip but were only used as a foodstuff in famines.