Tuesday, April 30, 2013

Conifers are of immense ecological importance

Aleppo Pine (Pinus halepensis) Siġra taż-żnuber

The conifers, are cone-bearing seed plants most being trees with just a few being shrubs. Typical conifers include the pines, cypresses firs, junipers cedars and redwoods. In Malta one can see a small number of native conifers in the countryside as well as several species of non-indigenous species in public and private gardens.

The best known species are the Aleppo pine, siġra taż-żnuber in Maltese and Malta’s national tree, the sandarac (għargħar in Maltese) a member of the cypress family. 

Although globally the total number of species is relatively small, conifers are of immense ecological importance. They are the dominant plants over huge areas of land especially in the boreal forests of the northern hemisphere. The area covered by conifers is so vast that they form a vast carbon sink trapping carbon which would otherwise add to the amount of carbon dioxide in the atmosphere thus exacerbating the green house effect about which we are hearing every day. Conifers are also of immense economic value as they are the primary source of timber and paper.

The leaves of many conifers are long, thin and have a needle-like appearance although some such as most of the cypresses have flat, triangular scale-like leaves. The leaves are often dark green in colour which may help absorb a maximum of energy from weak sunshine at high latitudes or under forest canopy shade. Conifers from hotter areas with high sunlight levels such as the Aleppo pine have yellowish-green leaves.

Many conifers have a distinctly scented resin, secreted to protect the tree against insect infestation and fungal infection of wounds. The resin of the Aleppo pine is used in Greece to give a particular wine known as retsina.

The size of mature conifers varies from less than one meter, to over 100 metres. The world's tallest, largest, thickest and oldest living things are all conifers. The tallest is a Coast Redwood, with a height of 115.55 metres. The largest is a Giant Sequoia, with a volume 1486.9 cubic metres. The thickest, or tree with the greatest trunk diameter, is a Montezuma Cypress, 11.42 metres in diameter. The oldest is a Great Basin Bristlecone Pine, 4,700 years old.

This article was published in The Times on 16 December 2013.

Conserving Maltese molluscs

Goat snail (Cantareus apertus) Mogħża
Molluscs are soft-bodied animals that more often than not have an external shell made of calcium carbonate.

The best known molluscs are the gastropods, bivalves and cephalopods.  In layman’s terms gastropods are the snails and slugs, bivalves are the two-shelled creatures such as oysters, clams and mussels and the cephalopods are the octopuses and squids. Molluscs are often found in aquatic habitats especially marine habitats.

There are about 93,000 species of molluscs in the world and more will be identified as more research is carried out. In Malta hundreds of species can be found on land and in the surrounding waters. Between 63 and 69 species are found on land. These include those species which live in fresh or brackish water. Surprisingly enough these include one species of freshwater bivalve. Of the gastropods, nine live in fresh water, nine are found in brackish water while the rest are terrestrial. Three species are not indigenous as they were introduced in the Maltese islands in relatively recent times. These species are restricted to a small number of public gardens.

One aquatic species which lived in the mouth of a spring is now probably extinct in the wild as building in the vicinity of the spring destroyed the source of fresh water which is needed by this particular species. This is not the only mollusc that has become extinct in the Maltese islands. Three species which lived in fresh water have not been seen in recent years. Other species are considered as vulnerable or threatened with extinction. The most endangered species live in restricted areas or habitats such as brackish water.

Maltese molluscs are also interesting because several are endemic to the Maltese islands, that is, they are not found outside the Maltese islands. Many of these endemics are restricted to a small area and can easily become extinct as well but in this case their extinction is far more serious as since they are not found living anywhere else they would be lost to humanity forever. This is not a remote possibility as more of the Maltese countryside is destroyed every year as happened to half the habitat of a particular species which now lies underneath a carpark.

The Maltese are responsible for the conservation of all the endemic Maltese species. There is nothing wrong with supporting the conservation of popular species such as whales but more importantly we must ensure that the small less glamorous species are protected and not allowed to become extinct.

This article was published in The Times on 9 December 2009.

Noticable Climate Change

The weather during November was noticeably warmer and drier than usual. Those visiting the countryside could realise that many plants started to flower earlier than usual and that insects that by this time of the year are usually dead or hiding remained active.

Some species of butterflies were especially common in areas where nectar-rich flowers such as those of the ivy were in bloom.

This unseasonal weather should get us thinking about the United Nations Climate Change Conference 2009 which is set to start next week in Copenhagen. The aim of this conference is to get the leaders of all the countries of the world to agree on how to fight global climate change and to ratify any agreement reached during the conference before 2012 when the Kyoto Protocol of 1997 expires.

There is general agreement nowadays that climate change is taking place and that immediate action must be taken to reduce the amount of carbon dioxide being produced by the burning of fossil fuels which are responsible for the rise in global temperature. Fossil fuels are the main source of energy production in both the developed and underdeveloped world.

In 1997 the USA was the largest consumer of fossil fuels but it has now been superseded by China and India both of which are arguing that their per capita consumption of fossil fuels is less than that of the United States and that therefore they should not be bound by the same commitments to reduce carbon dioxide production as developed nations.

Malta, as a member of the European Union, is committed to use more renewable sources of energy and rely less on fossil fuels on which we now depend for all our energy needs. Malta has a long way to go to be able to reach the targets to which it is committed. Other EU countries are way ahead. In 2007 Denmark obtained just under 17 percent of its energy from renewable sources. The target is to increase this to 20 percent by 2010 and 30 percent by 2020.

Combating global warming is of importance to Malta because climate change will have a negative effect on the Maltese islands. The rise in sea level will claim low lying areas and will reduce the amount of water in the sea-level aquifer on which we depend for much of the water we consume. Extreme weather will be more common creating havoc and hardship to all and the change in rainfall patterns will cause serious problems to the agricultural sector.

The Maltese government is responsible for the implementation of international pacts and agreements but it is the responsibility of everybody to avoid waste of energy and reduce energy consumption and thus lessen the production of damaging greenhouse gasses.

This article was published in The Times on 2 December 2009.

The devil's coach-horse beetle

The devil's coach-horse beetle is common and widespread in the Maltese countryside but not often seen because it is mostly active at night. It is found in most of Europe and has also been introduced to the Americas and parts of Australasia.

It belongs to a large family of beetles known as the rove beetles. Members of this family have short forewings, which cover only half the abdomen. The exposed abdomen is protected by hardened plates.

The devil’s coach-horse beetle can and sometimes does fly but when threatened it prefers to raise its abdomen like a scorpion and to open its jaws. This explains its Maltese name Katarina għolli denbek. In English speaking countries it is sometimes also called cock-tail beetle.

The sting has no poison but it can give a painful bite with its strong jaws. It can also secrete a foul smelling liquid from a pair of glands found at the end of its abdomen.
It feeds on other invertebrates such as insects and spiders as well as on carrion.

The specimen I photographed early in the morning was feeding on the remains of a snail that had been trodden upon by somebody a few hours earlier. When feeding it cuts its prey into small pieces with its mandibles and moulds them into a spherical shape using its front legs. It then chews and swallows then regurgitates it covered in a brown liquid which digests the material. When the solid material is completely liquefied swallows it. The larvae have similar eating habits.

In many parts of Europe this beetle has been associated with the devil since the Middle Ages. In Ireland it was believed that the devil takes the form of this beetle to eat sinners. It was supposed to bring bad luck and people could turn this to their advantage to acquire power over others.

This article was published in The Times on 25 November 2009.


Yellow throated crocus (Crocus longiflorus) Żagħfran salvaġġ 
Crocuses are among my favourite flowering plants. The cup-shaped flowers grow singly from small plants with sword-like leaves. similar to those of other members of the iris family to which crocuses belong. Their elegant shape is enhanced by their beautiful pastel colours which are usually in shades of lilac, mauve and yellow.

Crocuses are native to central and southern Europe.They can be found in areas from coastal to mountainous. They are also found in North Africa and the Middle East across Central Asia to western China.

In Malta we find only one species, the yellow-throated crocus, but more than 20 other species are found around the Mediterranean. This is a very large number when one considers that there are just 80 species of crocuses in the world.

The name crocus is derived from a Greek word (krokos) which is probably a variation of the Semitic word for saffron, a species of crocus. Saffron was widely cultivated when parts of the flower were used in cooking and seasoning and as a colouring agent.

The word saffron is derived from the Arabic word asfar, meaning yellow. Crocus cultivation was first recorded on the islands of Crete and Santorini on Minoan frescoes showing men gathering flowers. 

The yellow-throated crocus, like many other species of crocus, flowes in autumn after the first rains of the season but the term autumn crocus does not usually refer to these species but to a group of flowes, members of the lily family known as Colchicum.

Crocuses first appeared in The Nethetherlands in the 1560s. Plants were taken there from Constantinople by the ambassador of the Ottoman Empire.

These were taken to the botanical garden of the city of Leiden in south Holland. By 1620 several garden varieties had already been developed from these plants, the first of several varieties that nowadays have found their way throughout the world.

This article was published in The Times on 18 November 2009. 

Thursday, April 25, 2013

The sleep-inducing poppy

We are used to seeing large-flowered red poppies growing densely in fields. They sometimes grow in such profusion that fields resemble a red carpet.

The opium poppy, on the other hand, grows singly but its large beautiful flowers stand out and are easily noticed even by those who do not normally bother to look at wild flowers. It is an indigenous species and grows throughout the Mediterranean region, especially in southwestern Europe and in North Africa.
In Maltese, the plant is known as xaħxieħ.
Cultivated varieties of this species are the source of opium from which many narcotics, including morphine, codeine and noscapine, are produced. Morphine is also used to produce heroin.
The opium poppy has been used since prehistoric times. The ancient Greeks called the sap obtained from the flower ‘opion’ from which the current word opium is derived.
The scientific name of this poppy is Papaver somniferum. Papaver is the name of the poppy family and somniferum means sleep inducing.
Poppy seeds, an ingredient in many types of curries, are obtained from the opium poppy. The seeds are also used to produce an edible oil which is sometimes used as a salad dressing.
Some botanists are of the opinion that the opium poppy that grows in the Mediterranean region is not the same species as the cultivated species. This is based on the fact that they have different numbers of chromosomes. Botanists sometimes refer to the Mediterranean species as the poppy of Troy or the dwarf breadseed poppy.
Several other species of poppy can be found in the Maltese countryside. The most common species, the field poppy, is now in flower.
It is known in Maltese as pepprin. In a few weeks’ time, another species, the yellow-horned poppy known in Maltese as pepprin isfar, will appear.
This article was published in The Times on 25 April 2013.

Friday, April 19, 2013


Ferns are a very ancient family of plants they were already around more than 360 million years ago. They are older than land animals and far older than the dinosaurs. 

They were thriving on Earth for two hundred million years before the flowering plants evolved. They belong to a group of about 20,000 species of plants.

Several species have been recorded in the Maltese islands but only one, the maiden hair fern known in Maltese as tursin il-bir, is frequent. This species is found in shaded humid places such as the sides of deep valleys, inside wells, in cave openings and in humid courtyards. It is a native to western and southern Europe, Africa North America and Central America.

Like all plants, ferns have evolved to suit their environment. Ferns are very successful niche plants: they are well adapted to particular environmental niches - soil moisture, humidity, light, etc. They seldom grow outside these niches, some of which are very specific. Some can tolerate extreme drought and heat; others only live in the deepest rainforest.

Ferns are not as important economically as seed plants but have considerable importance. Some are used for food while many species are used in horticulture as landscape plants, cut foliage and as household plants. Several species are weeds but their most important use is as coal which consists of the remains of primitive plants mainly ferns.

Ferns are also found in the folklore of many countries. A theme that runs in many parts of the world is based on the fact that ferns do not produce flowers. In many places it was believed that once a year they produce mythical flowers or seeds and that anybody who finds them.

During the Victorian era there was a craze for fern collecting and the use of fern motifs in decorative arts including pottery, glass, metal and textiles which gave rise to the term Pteridomania.  

This article was published in The Times on 11 November 2009.

The deceiving mirror orchid

The mirror orchid is a beautiful insect orchid that is hard to spot but worth looking for.
Finding one in Malta is a question of being at the right place at the right time. One has a better chance of finding a few specimens in Gozo and Comino. Good places to look for these flowers are garigue habitats such as is found at Pembroke and at Ta’ Ċenċ in Gozo.
The mirror orchid is found across the Mediterranean region, from Portugal to Lebanon but is absent from Cyprus and northern Italy. On the other hand, it is common in some areas such as Sicily and southern Greece.
In Maltese, the mirror orchid is known as dubbiena kaħla. Its most striking feature is its lip or labellum. This structure is made up of three highly modified petals: it has a metallic mauve centre surrounded by a yellow border and a ring of brown hair at the perimeter.
The unusual shape and colours are a successful attempt by this orchid to fool the male of a species of scoliid wasp into mistaking it for a female. Both the insect and orchid have brown hairs while the mauve spot looks like the sky being reflected on the wasp’s wing.
The flower also produces a chemical similar to pheromone that is produced by the female wasp. The deception is so complete that the male scoliid wasp lands excitedly on to the flower and attempts to mate with it.
Mimicking female insects is a strategy used by insect orchids to attract male insects. In most species, the insects mimicked are bees and wasps.
While the insect is attempting to copulate, its head of body touches the orchid’s pollen sac which breaks off and becomes attached to its head or body where it remains until it is fooled by another similar flower.
This article was published in The Times on 17 April 2013.

The many facets of flax

The common flax is one of several species of flax, some of which are indigenous to the Maltese islands. It is an important crop plant that is cultivated as a food and as a fibre crop. Different varieties are grown in gardens.
The plant belongs to a family consisting of about 200 species that are found in both temperate and subtropical parts of the world.
Flax flowers are usually either blue or yellow, although in some species, the flowers can be red, white or pink.
Locally, seven species of flax have been recorded.
One indigenous species, the ascending flax (kittien aħmar), has not been seen for many years and is believed to be extinct in Malta while the pale flax (kittien ikħal) is very rare. On the other hand, the upright flax (kittien tal-imħarbat) and the southern flax (kittien isfar), both of which have yellow flowers, are common.
Flax fibre has been used to produce linen since ancient Egyptian times but the importance of the plant as a source of fibre decreased in the 19th century, when cotton became more popular – even though flax fibres are much stronger than cotton.
The seeds of the flax plant are the source of linseed oil (żejt tal-kittien), which is used as a nutrient as it is high in alpha- linolenic acid. This oil is, however, also used in paints, putty and varnishes, on its own or mixed with other oils, resins or solvents.
The largest flax growers are Canada and China, but significant amounts are also produced by India and the US.
The flax plant is the national flower of Belarus, and Northern Ireland has adopted it as its emblem.

This article was published in The Times on 10 April 2010.

Saturday, April 6, 2013

Seashells, seashells... in the bedrock

The Maltese islands are made up of different layers of sedimentary rock. In geological terms, the islands are very young. They were created long after dinosaurs became extinct and so it is impossible to find dinosaur fossils in any of the islands’ rocks.
The fossils found locally are mainly of marine organisms. The species of these organisms, however, change according to the layer in which they are found.Fossils are the preserved remains of plants and animals or their traces. They provide palaeontologists with important information about both the geology and biology of the earth. An object is considered a fossil if it is older than a certain minimum age, which for most palaeontologists is 10,000 years. The oldest fossils are about 3.4 billion years old.
The oldest layer, the lower coralline limestone, is made up mainly of reef-forming organisms such as calcareous algae and coral, where one is more likely to find bivalve seashells. At the very top of the lower coralline limestone layer is a shallow but very concentrated layer of large flat sea urchins.
The globigerina limestone layer is made up of the remains of planktonic organisms. Some parts of this layer are rich in fossils of free-swimming organisms such as scallops as well as bottom-living creatures such as sea urchins and crustaceans.
Blue clay was formed from a sediment that originated on land, probably from eroding landmasses to the north that were being uplifted as a result of tectonic action. Fossils in this layer are few, and are mainly molluscs and coral.
The penultimate layer, the greensand, is absent in many parts of Malta but forms a thin layer in many parts of Gozo. Greensand is characterised by its orange-brown colour (green before being exposed to air) and large amount of fossils.
The most obvious fossils belong to large sea urchins but fossilised fish have also been found in some places. The topmost layer, the upper coralline limestone, which was the last layer to form, is similar to the oldest layer, the lower coralline limestone.
This article was published in The Times on 3 April 2013.

Wednesday, April 3, 2013

Fearsome scorpions

Scorpions are arachnids, a class of invertebrate animals in which we also find spiders, ticks and mites.
Scorpions are found on all continents except Antarctica. Over 1,700 species have been identified but only one species is found on our islands.They are easily recognised as they have a pair of segmented claws and a segmented tail that is often kept arched over their back. The end of the tail is a stinging organ that can deliver a poison.
The scorpion is known in Maltese as skorpjun but we also have a Semitic name for it – għakreb – which probably nobody uses anymore.
The Maltese scorpion is a small predator that lives under stones and leaves but is also found in houses, especially in basements.
I have seen more scorpions in houses than in the countryside although this might be because they are nocturnal creatures and keep well hidden during the day.
By being active at night scorpions avoid predators that are active during the day.
They feed on smaller animals, especially insects, and can help in the biological control of harmful insects and pests. Before eating, they kill or paralyse their prey by stinging it and injecting it with poison.
About 25 species of scorpion can deliver a poison that is strong enough to kill a human. However, the poison carried by the Maltese scorpion is very weak: it might be able to kill a small creature but its effect on humans is similar to that of a mosquito bite.
The poison is also used to defend themselves from predators but the poison of the local species is not even strong enough for this. I once saw a wall lizard catching and eating a scorpion without coming to any harm.
For their size, scorpions are long-lived creatures with many species living for four years and with one species believed to have a life span of 25 years.
This article was published in The Times on 27 March 2013.

Tuesday, April 2, 2013

The shrub tobacco

The tobacco tree is another alien species that has found its way to the Maltese Islands as a cultivated decorative plant. 

It is now found in the countryside especially in rubble, building sites old walls and fortifications. It was originally native of Bolivia, Paraguay and Argentina but has now become naturalised in many parts of the world especially around the Mediterranean and southwestern United States.

Known in Maltese as tabakk tas-swar, this species is actually a small tree that usually grows up to about two metres but which can sometimes be more than seven metres high. The shrub tobacco is also known as the glaucous tobacco and by many other names including mustard tree, Brazilian tree tobacco and tree tobacco.

In warm climates it flowers all year round and produces large quantities of seeds. In Malta the long and narrow yellow flowers are seen mostly between spring and autumn.

The shrub tobacco is an invasive species and in many areas where it has been introduced it is considered as a pest and action is taken to eradicate it because of its ability to displace indigenous species. In other areas it is considered as a medicinal plant and is even used to produce biofuels.

It is related to the tobacco plant which is the source of the tobacco used for smoking. In fact both belong to the Nicitiana family a name given in honour of Jean Nicot (1530-1600), a French diplomat, who is said to have introduced tobacco to Europe as snuff (powdered tobacco that is sniffed up the nostril) to the French court.

Shrub tobacco is being studied as a potential treatment for nicotine addiction since it does not contain nicotine, but similar chemicals.  It is claimed that the leaves are smoked for ritual purposes by the Navajo Indians however, smoking and/or ingesting the plant has lead to death as all parts of the plant contain chemicals that have insecticidal properties which make all parts of the plant extremely poisonous and thus unpalatable to insects and other animals. 

The showy balloon vine

The balloon vine is a perennial plant from tropical Africa, Asia and America and was indigenous in the Bermudas, Florida and Texas. It is a climber and uses tendrils to reach the top of whatever it is growing on and often blankets vegetation completely. It has light green compound leaves and small white flowers that are produced throughout most of the year. 

Its most distinguishing feature is its fruit which is a green thin-walled, papery, inflated capsule that resembles a ribbed balloon which contains three black seeds. These capsules can be carried by wing and float on water.

The balloon vine, known in Maltese as sfineġ, was introduced in Malta as a decorative plant because of its fruit. It now grows in the Maltese countryside and although it is not very common wherever it sets a foothold it grows aggressively covering trees and bushes and whatever is in the vicinity.

It is now found in many parts of the world and is considered as an invasive species in many areas and action is taken to remove or control it.

This species belongs to a genus of plants known as Cardiospermum. This name which means “heart seed”, refers to the plant’s pea-sized dark brown seeds which bear a typical white, heart-shaped spot on their surface and in fact members of this genus are also known as love in a puff, heartseed or heartseed vine.

Native Amazonians string balloon vine seeds into armbands that are worn to ward off snakes

In Indian herbal medicine, balloon vine root is used to bring on delayed menstruation and to relieve backache and arthritis. Balloon vines are not traditionally known for their medicinal properties in the western world but in more recent times extracts from their seeds are included in skin creams that claim to treat eczema and other skin condition. The leaves are believed to stimulate local circulation and are applied to painful joints to help speed the clearing of toxins. The seeds are also thought to help in the treatment of arthritis. The plant as a whole has sedative properties.