project reflections #26

Burn Weed

It is my hope that it has now become apparent to the reader how many of the pioneering plants that I have thus far described employ – by means of adaptation – various ingenious biological defenses against the animals that might eat them.

These defenses constitute the great armoury of spines, thorns, prickles, bristles – and bitter, unsavory compounds and poisonous concoctions – that botanical nature has designed and brewed up to deter animal interest, investigation, and ingestion.In terms of our human experience of these arms and fortifications, there can surely be no more commonly suffered strategy than the sting of the common nettle – Urtica dioica. Every child – and every parent – must surely be conscious of that shockingly unpleasant ‘first contact’ with this painful weed; of the alarming white bumps and reddened skin that we associate with ‘nettle rash’.

Stinging nettle or common nettle, Urtica dioica, is a herbaceous perennial flowering plant, native to Europe, Asia, northern Africa and North America – it is the best-known member of the genus Urtica. The plant has many hollow stinging hairs called trichomes on its leaves and stems, which act like hypodermic needles; injecting histamine and other chemicals that produce a stinging sensation when contacted by humans and other animals. The plant has a long history of use as a medicine and as a food source.

Stinging nettle is a dioecious herbaceous perennial, 1 to 2 m (3 to 7 ft) tall in the summer and dying down to the ground in winter. It has widely spreading rhizomes and stolons, which are bright yellow, as are the roots. The soft green leaves are 3 to 15 cm (1 to 6 in) long and are borne oppositely on an erect wiry green stem. The leaves have a strongly serrated margin, a cordate base, and an acuminate tip with a terminal leaf tooth longer than adjacent laterals. It bears numerous small, greenish or brownish flowers in dense axillary inflorescences.

The leaves and stems are very hairy with non-stinging hairs and they also bear many stinging hairs (trichomes), whose tips come off when touched, transforming the hair into a needle that will inject several chemicals: acetylcholine, histamine, 5-HT (serotonin), moroidin, leukotrienes, and – possibly – formic acid. This mixture of chemical compounds causes a painful sting or paresthesia from which the species derives its common name, as well as the colloquial names: burn nettle, burn weed, burn hazel.

Urtication, or flogging with nettles, is the process of deliberately applying stinging nettles to the skin in order to provoke inflammation. An agent thus used is known as a rubefacient (something that causes redness). This is done as a folk remedy for rheumatism, providing temporary relief from (or at least a novel replacement for) pain in the joints.

As Old English stiðe, nettle is one of the nine plants invoked in the pagan Anglo-Saxon Nine Herbs Charm, recorded in the 10th century. Nettle was believed to be a galactagogue, a substance that promotes lactation.

Because it contains 3,4-divanillyltetrahydrofuran, certain extracts of the nettle are used by bodybuilders in an effort to increase free testosterone.

An annual Stinging Nettle Eating Championship draws thousands of people to Dorset, where competitors attempt to eat as much of the raw plant as possible. Competitors are given 60 cm (20 in) stalks of the plant, from which they strip the leaves and eat them. Whoever strips and eats the most stinging nettle leaves in a fixed time is the winner. The competition dates back to 1986, when two neighbouring farmers attempted to settle a dispute about which had the worst infestation of nettles.

In Europe stinging nettles have a strong association with human habitation and buildings. The presence of nettles may indicate that a building has been long abandoned. Human and animal waste may be responsible for elevated levels of phosphate and nitrogen in the soil, providing an ideal environment for stinging nettles.

Paul Evans, February 2012

project reflections #20

Sycamore

In order to escape the violent winds that blew in these parts throughout early January, I took to rambling through the scattered woodlands along the banks of the river Don. Here I found many large sycamore maples or Acer pseudoplatanus  – a magnificent tree that will sometimes grow to a height of over a hundred feet.

I have observed that, in wet ground at the base of these sycamores, the rocking movement of the tree in high winds – transmitted from the upper branches down through the solid trunk – results in oscillatory movements within pools formed from groundwater. This fluid moves up and down with the back and forth movement, resulting in the water rising up and withdrawing – almost like breath – and often expelling the liquified soil to create cavities amongst the roots. These cavities are, I am led to understand, known as oscillants …

Acer pseudoplatanus, the sycamore maple, is a species of maple native to central Europe and southwestern Asia, from France it is naturally distributed eastwards towards the Ukraine, and south to northern Spain, northern Turkey, and the Caucasus. It is not related to other trees called sycamore or plane tree in the Platanus genus. Its apparent similarity to the species of that genus led to its being named pseudoplatanus, using the prefix pseudo- (from the Ancient Greek for “false”). Other common names for the tree include false plane-tree, great maple, Scottish maple, mock-plane, sycamore or Celtic maple.

It is a large deciduous tree that reaches 20–35 m tall at maturity, with a broad, domed crown. On young trees, the bark is smooth and grey but becomes rougher with age and breaks up in scales, exposing the pale-brown-to-pinkish inner bark. The leaves are opposite, large, 10–25 cm long and broad with a 5–15 cm petiole, with a leathery texture, palmately veined with thick veins protruding on the underside surface, with five lobes with toothed edges, and dark green in colour with a whitish underside. The leaves are often marked with black spots or patches which are caused by the fungus Rhytisma acerinum. The monoecious yellow-green flowers are produced in spring on 10–20 cm pendulous racemes, with 20–50 flowers on each stalk. The 5–10 mm diameter seeds are paired in samaras, each seed with a 20–40 mm long wing to catch the wind and rotate when they fall; this helps them to spread further from the parent tree. The seeds are mature in autumn about 6 months after pollination.

The name “sycamore” originally belongs to the fig species Ficus sycomorus, which is native to southwest Asia (this is the sycamore or sycomore referred to in the Bible). The name was later applied to this species by reason of the superficial similarity in leaf shape.

The sycamore is cultivated and widely naturalised north of its native range in northern Europe, and it now occurs throughout the British Isles, having been introduced in the 17th century. It is considered to be an environmental weed in environmentally sensitive locations.

The wood is a medium weight hardwood, weighing 630 kg per cubic metre. It is traditionally used in making the backs, necks and scrolls of violins. The flowers produce abundant nectar, which makes a fragrant, delicately flavoured and pale-coloured honey.

Paul Evans, 8 January 2012

project reflections #18 (Wardsend Cemetery, Sheffield, 5 January 2012)

Wardsend was opened in the early 1850s, when a nearby churchyard became full. The name Wardsend is a corruption of “Worldsend”, which is reputed to be the site of the second coming of Christ, and is listed in a land agreement in 1161.

The site of the cemetery (see map opposite) occupies 5.5 acres and once included a small chapel, office and a sexton’s house. The railway line runs through the cemetery, dividing it into a western half which is wooded and an eastern half which is open (see pictures).

The first burial was in 1857 and was of Mary Ann Marsden aged 2 years. By tradition the first body was always given the title of “Guardian of the Cemetery”. By 1900 the number of burials totalled 20,000 and the site was extended.

P. Quincey, Burngreave Messenger

project reflections #17 (Wardsend Cemetery, Sheffield, 5 January 2012)

George Lambert VC (16 December 1819 – 10 February 1860), born C0unty Armagh, was a recipient of the Victoria Cross, the highest award for valour in the face of the enemy.

A Sergeant-Major in the 84th Regiment of Foot (later the 2nd Battalion, York and Lancaster Regiment), he died in Sheffield on February 10, 1860.

84th Regiment. Sergeant-Major George LambertDate of Acts of Bravery, 29th July, 16th August, and 25th September, 1857For distinguished conduct, at Onao, on the 29th of July; at Bithoor, on the 16th of August; and at Lucknow, on the 25th of September.
(Extract from Field Force Orders of the late Major-Gcneral Havelock, dated 17th October, 1857.)

project reflections #16 (Wardsend Cemetery, Sheffield, 5 January 2012)

There used to be a chapel and a sexton’s cottage at Wardsend Cemetery. The cottage was burned down by rioters on 3rd June 1862 when a crowd tried to get hold of a gravedigger suspected of selling bodies for dissection. The gravedigger was later sentenced to 3 months – not for selling bodies but for selling the same graves over and over.

Martin Elms

project reflections #14

Fireweed

The branches come out of the ground in great numbers, growing, to the height of sixe foote, garnished with brave flowers of great beautie, consisting of fower leaves a piece, of an orient purple colour. The cod is long … and full of downie matter, which flieth away with the winde when the cod is opened.

John Gerard, The Herball, 1597

Rosebay Willowherb, or Fireweed as it is know in North America, is both abundant and widely distributed throughout the Upperthorpe and Netherthorpe edgelands.

It has, to my mind, the great distinction of two quite separate yet equally spectacular stages in its reproductive cycle. The first occurs with the flowering of the vivid magenta spears – often seen waving in stark chromatic contrast against the blue of the summer sky. The second stage occurs at the end of the ripening within the seed pods of the delicate and silk-like seeds – on the warmest days the rising air currents will be alive with these delightful, dancing, graceful strands as they make their escape …

Epilobium angustifolium, commonly known as Fireweed, or Rosebay Willowherb, is a perennial herbaceous plant in the willowherb family Onagraceae. It is native throughout the temperate Northern Hemisphere, including large parts of the boreal forests. The species name angustifolium is a portmanteau of the Latin words angusti meaning ‘narrow’, and folium meaning ‘leaf’.

Rosebay Willowherb is often abundant in wet calcareous to slightly acidic soils in open fields, pastures, and particularly burned-over lands; the name Fireweed derives from the species’ abundance as a coloniser on burnt sites after forest fires. Its tendency to quickly colonise open areas with little competition makes it a clear example of a pioneer species. These plants grow and flower as long as there is open space and plenty of light; as trees and brush grow larger the plants die out, but the seeds remain viable in the soil seed bank for many years – and when a new conflagration or other disturbance occurs that opens up the ground to light again the seeds germinate. Some areas with heavy seed counts in the soil can, after fire, be covered with pure dense stands of this species and when in flower the landscape is turned into fields of colour.

In Britain the plant was considered a rare species in the 18th century, and one confined to a few locations with damp, gravelly soils. It was sometimes mis-identified as Great Hairy Willowherb in contemporary floras. The plant’s rise from local rarity to widespread weed seems to have occurred at the same time as the expansion of the railway network, and the associated soil disturbance.

Rosebay Willowherb became locally known as bombweed due to its rapid colonisation of bomb craters in the Second World War.

The reddish stems of this herbaceous perennial are usually simple, erect, smooth, 0.5–2.5 m (1½–8 feet) high with scattered alternate leaves. The leaves are entire, lanceolate, and pinnately veined. The radially symmetrical flowers have four magenta to pink petals, 2 to 3 cm in diameter. The styles have four stigmas, which occur in symmetrical terminal racemes. The leaves of fireweed are unique in that the leaf veins are circular and do not terminate on the edges of the leaf but form circular loops and join together inside the outer leaf margins. This feature makes the plants very easy to identify in all stages of growth. When fireweed first emerges in early spring, it can closely resemble several highly toxic members of the lily family. However, it is easily identified by its unique leaf vein structure.

The reddish-brown linear seed capsule splits from the apex. It bears many minute brown seeds, about 300 to 400 per capsule and 80,000 per plant. The seeds have silky hairs to aid wind dispersal and are very easily spread by the wind. Once established, the plants also spread extensively by underground roots, an individual plant eventually forming a large patch.

The young shoots were often collected in the spring by Native American people and mixed with other greens for eating. They are best when young and tender: as the plant matures the leaves become tough and somewhat bitter. The southeast Native Americans use the stems in this stage. They are peeled and consumed raw. The root can be roasted after scraping off the outside, but often tastes bitter. To mitigate this, the root is collected before the plant flowers and the brown thread in the middle removed. The Dena’ina add fireweed to their dogs’ food.

Fireweed is also a medicine of the Upper Inlet Dena’ina, who treat pus-filled boils or cuts by placing a piece of the raw stem on the afflicted area. This is said to draw the pus out of the cut or boil and prevents a cut with pus in it from healing over too quickly.

Fireweed is the floral emblem of Yukon.

Paul Evans, 3 January 2012