Monday 26 December 2016

Spotted medick



Spotted medick (Medicago arabica) is found in the south and east of England, mainly in grassy environments such as pastures. It is otherwise known as Calvary clover, from an old folk belief that the dark spots seen on its leaves were caused by Christ’s blood falling on a specimen of the plant that was growing at the foot of the Cross.

The plant grows to a maximum height of 24 inches (60 centimetres) although many stems trail along the ground. The leaves grow as sets of three leaflets, which might lead to people mistaking the plant for a kind of clover. The dark spots are seen most easily as the leaves age and start to turn brown.

Small bright yellow flowers appear on stalks between April and August. These are replaced by pods that coil into a spiral that has a double row of spines. These enable ripe pods to be pulled off the plant and carried some distance on the legs and flanks of passing animals.

When on the ground, the pod does not split open to release the seeds. Instead, one of the seeds will germinate inside the pod and send a shoot through the pod’s wall to find soil in which to root itself. The rest of the pod will often remain attached to the new plant as it grows.

© John Welford

Friday 23 December 2016

Ornitholestes



Ornitholestes was a meat-eating coelurosaur dinosaur that lived around 155 million years ago which is towards the end of the Jurassic period. This was about the time that the first birds were appearing, having evolved from reptiles, and the name Ornitholestes means “bird robber” because it was originally supposed that the animal preyed on early birds and their nests. However, this is unlikely given that birds were evolving in what is now Europe and the very rare fossils of Ornitholoestes have only been found in what is now the state of Wyoming.

Ornitholestes was no great size, being only about two metres (six feet) from nose to tip of tail. It would therefore have relied on its speed for catching its prey and escaping from larger predators. It may also have developed keen senses of sight and smell for the same purposes.

Ornitholestes had small sharp teeth and strong arms that ended in long claws. These suggest that the animal might have preyed on the young of other dinosaur species, possibly grabbing them as they hatched from their eggs and making off at speed when the parents realised what was happening. The “robber” part of the name was therefore quite likely to have been appropriate, although the eggs and young being attacked were not those of birds!

© John Welford 

Lucerne



Lucerne (Medicago sativa) is a plant that grows wild throughout Great Britain although it is a non-native species (of Mediterranean origin) that started off as a “tame” one but escaped.

Lucerne is otherwise known as alfalfa, and it has uses as a fodder crop due to its high protein and vitamin content. Farmers have traditionally used lucerne to improve the productivity of their land, because the roots develop small nodules that “fix” nitrogen. This means that nitrogen is taken from the air and transferred to the soil where it becomes an essential plant food.

Wild lucerne grows as a bushy plant up to 36 inches (90 centimetres) high. The leaves split into three leaflets that are toothed towards the ends. The plant flowers in June and July, with the purple (sometimes yellow) flowers clustered near the stem tips.

The flower has an interesting mechanism for achieving pollination. The stamen (male) and stigma (female) parts of the flower are tensioned such that when a bee (or other heavy insect) lands on a flower, the stigma springs up and hits the bee, thus being able to collect any pollen that the bee was carrying. Likewise, the stamen deposits more pollen on the bee that it then carries to the next flower.

The seed pods coil into spirals, each containing many seeds. It is possible to make a salad garnish from lucerne/alfalfa seeds by allowing them to sprout in a glass jar and eating the seedlings, which have a nutty flavour.

© John Welford

Monday 19 December 2016

Dyer's greenweed



Dyer’s greenweed (Genista tinctoria) is a plant that is related to broom and is found in England and Wales but only rarely in Scotland. It prefers clay and chalky soils and in often found in grassy places.

It comprises a small shrub that grows up to 28 inches (70 centimetres) in height. It has smooth green stems from which the leaves, which are discarded in winter, grow directly. Unlike some other brooms, dyer’s greenweed does not have spines.

The plant flowers from July to September, the flowers forming bright yellow spikes at the ends of the stems. Brooms are members of the pea family, and this is especially noticeable from the long pods that contain the seeds. When the seeds are ripe, the pods twist open suddenly and the seeds are ejected.

The name comes from the fact that a yellow dye can be prepared from the flowering stems. In the 14th century, immigrant Flemish weavers used the dye in combination with blue woad to produce green-coloured cloth. This was traditionally done in the Lake District, where the resultant colour was known as Kendal green.

© John Welford

Saturday 17 December 2016

Indian balsam



Indian balsam (Impatiens glandulifera) is a plant that grows wild in several parts of the United Kingdom but it is no means a native plant, as might be gathered from its name. It is known that it first reached the UK from India in 1839, introduced as a greenhouse plant, but seeds escaped and led to wild populations getting a foothold. Where it occurs, Indian balsam does very well on waste ground and on river banks.

Indian balsam can grow as high as 80 inches (200 centimetres). It has sturdy ribbed stems that bear pointed leaves growing in groups of three and pointing in different directions. It produces large purplish flowers from July to October.

The pear-shaped fruiting capsules release ripe seeds by springing back their sides and throwing the seed a considerable distance. This can happen when the plant is touched by a passing person or animal.

Pollination is ensured by the shape of the flower which closes completely around any bee that visits to takes its nectar, although the trapping is only temporary. The insect has no choice but to touch both stamen (male) and pistil (female) as it moves from flower to flower and therefore to transfer pollen.

© John Welford

Friday 16 December 2016

Common stork’s-bill



Common stork’s-bill (Erodium cicutarium) certainly lives up to its name in respect of the first element, in that it is commonly found throughout Great Britain, particularly in gravel pits, dry grassland and on the margins of sandy beaches.

The plant grows up to 20 inches (50 centimetres) high, although some of the stems grow lengthways close to the ground. The leaves comprise double rows of leaflets of varying shapes.

Common stork’s-bill flowers from May to September, but each flower can be very short lived – appearing in the morning but dropping its petals by noon. The flowers are pink with the five petals longer than the sepals.

Common stork’s-bill is notable for the extraordinary method it has of propagating its seeds. Each fruit has five narrow segments that together form the “stork’s-bill” of the second element of the plant’s name. When the seed is ripe, the “bill” twists at the base and the five seeds are released, each at the end of a corkscrew-like filament.

When the seed falls the corkscrew is still attached, and this then tightens or loosens with variations in humidity. The effect is that the corkscrew buries itself in the ground, taking the seed with it. There are backward-pointing hairs on the stem that prevent the seed from re-emerging from the soil. When the seed is at the correct depth for germination the corkscrew ceases to operate.


© John Welford

Massospondylus: a dinosaur from the Jurassic era



Massospondylus was a prosauropod dinosaur that lived around 200 to 185 million years ago, which places it in the early Jurassic period when reptiles were the dominant life form on planet Earth.

Massospondylus lived mainly in what is now Africa. More than 80 fossils of Massospondylus (in various states of completion) have been found, which has enabled it to be one of the best-studied dinosaurs.

It was about 4.5 metres long with half of this being its tail. It had strong hind legs, which would have been useful both for escaping from predators and for reaching the high-growing vegetation that was almost certainly its food source.

Given the small size of its head (and therefore jaw), as compared to its body, Massospondylus would have had to spend a large proportion of its waking hours eating. The animal’s front teeth were large and strong – ideal for biting the tough stems of fern-like plants – but its other teeth were not adapted to chewing. This suggests that the food was gulped straight down and then mashed up in the stomach, possibly aided by stones that Massospondylus would have swallowed.

© John Welford

Monday 12 December 2016

Herb-robert



Herb-robert (Geranium robertianum) is a member of the crane’s-bill family of plants, a number of whose members are found growing wild in the United Kingdom and elsewhere. Herb-robert is commonly found under hedges, on rocks and walls and in woodland, preferring shady places rather than full sunlight.

Herb-robert grows up to 20 inches (50 centimetres) high, its stems branching from the base but some sprawling across the ground as opposed to standing upright.

The leaves are fern-like in shape with three to five lobes. The stems and leaves, which are hairy, turn bright red in autumn or if the plant is growing in dry conditions. This might be a reason why the plant has the name it does, in that “robert” is a corrupted form of the Latin word for red, namely “ruber”.

Herb-robert flowers from May to September, the flowers being pink and the petals rounded and not notched. Although the fruits are slightly wrinkled, the seeds are smooth.

It was typical in medieval times for plants to be ascribed curative powers based on their appearance, the belief being that everything in Nature had been designed by God to be of direct benefit to humanity, and He left clues on each plant as to what that purpose was. In the case of herb-robert, the red colour mentioned above signified the plant’s efficacy in treating blood disorders or staunching the flow of blood.

However, the leaves also produce a disagreeable smell, and the plant is therefore sometimes known as “Stinking Bob”.


© John Welford

Sunday 11 December 2016

Dove's-foot crane's-bill



Dove’s-foot crane’s-bill (Geranium molle) is a common wildflower plant in lowland Great Britain, being found in fields, wasteland and sandy areas.

This variety of crane’s-bill is noticeable for the soft hairy down on its roundish lobed leaves (the botanical name “molle” is Latin for soft). The semi-erect stems, which branch from the base of the plant, grow up to 16 inches (40 centimetres) high.

The plant flowers from April to September. The pointed sepals are covered with dense hair and the lilac/purple flowers have five notched petals. Although the flowers are attractive to insects, the stamens (male) and stigmas (female) are in close contact so the flowers are actually self-pollinating.

The name crane’s-bill comes from the shape of the fruit, which has been thought to resemble the bill of the crane – a stork-like bird. When ripe, the fruit ejects a seed which is thrown some distance from the plant.

The name dove’s-foot comes from the shape of the leaf, which some people have seen as resembling the shape of a dove’s foot, although this takes a considerable leap of imagination!

As with many common wild flowers, dove’s-foot crane’s-bill has been used in the past by herbalists to treat certain ailments. One of the more bizarre applications was that advocated by John Gerard in the 16th century. He prescribed a cure for ruptures in which a powder was made from dried plants to which was added a powder made by grinding up nine dried slugs! The combined powder was then stirred into claret and drunk. Were any ruptures healed as a result? Or did the excuse to drink copious amounts of claret – albeit strangely flavoured - simply make sufferers forget that they were in discomfort?


© John Welford

Thursday 8 December 2016

Hedgerow crane's-bill



Hedgerow crane’s-bill (Geranium pyrenaicum) is also known as the Pyrenean or mountain crane’s-bill, because it grows in mountainous regions of Southern Europe, but it is only found as a lowland plant in the United Kingdom (notably the south and east of England). It is not native to Britain, having first been recorded here in 1762. Formerly a rare plant, it has increased in numbers in recent years and it is especially prevalent in overgrown churchyards, growing alongside grasses and dandelions. It is also found in hedgerows, field margins and on wasteland.

The plant has upright stems between 9 and 24 inches (23-60 centimetres) high. The rounded leaves are “half lobed” in that the indentations go only half way to the midrib. The flowers, which appear between June and August, are light purple and grow in pairs. The sepals are oval and pointed and the petals deeply notched.

The name crane’s-bill comes from the shape of the pointed fruits, which are thought to resemble the beak of the crane (a bird resembling the stork). The fruits are smooth and downy, each containing a single seed. A long thin style runs up the outside of each fruit. When the seed is ripe the style acts like a spring, flinging the seed up to 10 feet (3 metres) from the parent plant.

The botanical name of this plant could be taken to mean that it is related to the garden plants with bright red flowers that are generally knowns as geraniums. However, the latter is a member of the Pelargonium family.

© John Welford