It is the height of summer. A rainy night has turned into a hot day of blue sky and fluffy white clouds. The wind that had been rustling the leaves of the nearby forest all night has died down. Now the world is cocooned into the peaceful silence of glimmering summer heat which is only interrupted by the occasional song of the Skylark and the buzzing of flies and bees.
I am in the middle of a meadow. The tall stems of blooming grasses form a green ocean around me. Here and there flower heads sprinkle dots of colour onto the waves of green: Devil’s Bit Scabious provides the purple, Bulbous and Meadow Buttercup add yellow, the Greater and Common Knapweed are responsible for red and the Ox-Eye Daisy displays rosettes of pure white. Some of the flowers have already served their purpose and are slowly fading away in warm tones of brown, reminding me that summer in Ireland is short lived and fragile.
It is almost midday, and the sun overhead has long burned away the raindrops that had clung onto the leaves, petals and spiderwebs. I am diving beneath the coloured surface of the meadow. Down here, close to the ground, is a different world. More flowers reveal themselves, these ones even more intricate and intriguing than the ones on the surface. The Pyramidal Orchid shows off with a cluster of tiny, gleaming pink flowers arranged in the distinctive pyramidal shape and the Bee Orchid’s elaborate design is beyond description, it can just be marvelled at. The Eyebright right beside the orchids comes along more humble, but the minute flowers, showing a simple purple and yellow pattern on white, evaporate a gracile beauty nevertheless. There are also clovers, red and white, and Selfheal. Through the stalks I can spot a patch of Wild Thyme and a bunch of Wild Marjoram at the edge of the meadow. Beetles and ants go about their business in this temporary jungle. Out of the corner of my eye I see a Peacock butterfly dancing to the song of the Skylark in the sky above. I close my eyes and give myself to the sounds and smells of the meadow.
Flowering plants are one of the great wonders of the natural world and Ireland is home to a wide variety of them. Flowering plants are not only transforming the countryside into a kaleidoscope of colours and have inspired poets, painters and other artists for centuries, without them life as we know it would not be possible because they are a major food source for other creatures including ourselves.
Flowering plants are scientifically known as angiosperms, which is derived from the Greek words for vessel (angio) and seed (sperm). The name is hinting at the reproduction process of flowering plants, the end product of which is one or many seeds embedded or attached to a vessel. To us this vessel is better known as the fruit which comes on the form of berries, nuts, grains and beans to name but a few and these fruits are the foundation of countless food chains all over the planet.
Before angiosperms changed the world, plants reproduced in a much more simple way. These early plants that appeared for the first time some 500 million years ago and which survived as ferns, horsetails and clubmosses until today, don’t produce flowers or seeds. Instead they reproduce by spores, simple but effective one-celled reproductive units. Through these units the plant can produce offspring by cloning itself without the need of outside help, which is a safe way to secure the survival of their species.
Why plants evolved from spore producing and therefor independent individuals to flowering plants that need outside support is a big mystery, but without this evolution our planet would be looking very different today. The first flowering plants evolved around 130 million years ago, in geological terms a rather recent event. The first flower was most likely a small inconspicuous thing. Scientists are still not clear what this very first flower exactly looked like and where, how and from what it evolved. At the moment it is thought that Amborellaceae, a family that today includes just one known species, Amborella trichopoda, a small woody plant that only grows on the pacific island of South Caledonia, represents the oldest living lineage of flowering plants. From those humble beginnings the angiosperms began to diversify and started their conquest of the globe. Today almost 90% of all plants are angiosperms, they can be found from the tropics to the arctic, thrive from sea level to mountain top and have diversified into close to 300.000 species.
The new concept that set flowering plants apart from all other plants was a reproduction method similar to that of the animal world. A male reproductive cell, the pollen, had to be delivered to a female reproductive organ, the ovary, and once these two had come together, an event known as pollination, the offspring, the seed, was born. And the flower was the key to this concept.
Angiosperms can be divided into two major groups. Flowering plants that grow woody parts, the trees and shrubs, form one group and the herbaceous plants the other. The latter is probably the reason for the overwhelming success of the angiosperms. While trees and shrubs take years to mature and bear seed, herbaceous plants have a much shorter life cycle and can live, reproduce and die within a few months. This allows these plants to colonize new ground very fast and expand their range quickly. It was also the herbaceous plants that brought the flower to a whole new level. The flowers on most trees and shrubs are small and undecorated for the simple reason that these plants rely on the wind for pollination so there is no need for any kind of fancy display. Petals, the large and often colourful leaves we associate with flowering plants, appeared for the first time around 100 million years ago. These petal bearing plants didn’t count on the unreliability and crude delivery system of the wind anymore, they were trying to attract insects that would then transport their pollen directly from one plant to the next. What followed was a co-evolution of angiosperms and insects, a time known as the great radiation. The plants started to diversify at an immense rate and were adding colour patterns, an array of smells and food in the form of nectar to their arsenal in order to attract pollinators. In turn insects adapted and diversified as well and over time even other animals like birds, lizards and bats were joining the ranks of pollinators. In many cases the relationship between plant and pollinator became very special. Flowers that rely on bees have markings in the ultraviolet spectrum that most other insects can’t see. Butterfly pollinated flowers are red, yellow and orange, colours bees can’t see, and often have the nectar hidden deep inside the flower so it can only be reached by the butterfly’s especially adapted long, straw-like proboscis. Flowers that depend on night active bats or moths release their scent only after dark and are often white, which makes them easier to be seen in moonlight.
While the delivery person and method of attraction differs, the actual process of pollination is the same in all angiosperms. The important reproductive organs can be found in the center of the flower and are surrounded by the petals and sepals. The latter are the leaves that protect the flower while it is still closed. The male reproductive organ is the stamen which is made up of the anther, which produces the pollen, and the stalk or filament, which carries the anther. In most flowers a number of stamens are arranged around the female reproductive organ, the carpel. The carpel consists of the stigma on the top, and the style, which is a tube that connects the stigma with the ovary at the bottom. Inside the ovary sit the ovules, the egg cells. To prevent self-fertilization the male (the pollen) and female (the ovules) gametophytes on the same plant mature at different times and in addition female plant parts don’t accept just any pollen. How the flower sorts compatible from incompatible pollen is however still an area of active research. Once the right pollen has been delivered onto the stigma, the pollen grows a tube down the style and into the ovary. Through this tube the sperm cells are delivered to the ovules and fertilization takes place. The ovule will then develop into the seed and the surrounding ovary into the fruit.
The fruit is a further pillar on which the mutual beneficial relationship of angiosperms and animals is built. For the animal the fruit is a food source, for the plant it is the means that turns the animal yet again into a delivery system. The animal devours the fruit, the fruit passes through the animal’s digestive track and while the fruit itself is digested the seed survives the journey and sees the light of day again far away from its place of origin. It is an ingenious way to travel fast and far to colonize new areas. This way of transport allowed the angiosperms, especially the herbaceous varieties, to expand rapidly, which in turn allowed animals to migrate to and settle in new places.
The history of Ireland’s flowering plants starts towards the end of the last glaciation some 12.000 years ago. Warmer temperatures allowed plants to extend their range and the post-glacial, tundra-like landscape soon developed into a vast grassland similar to today’s African steppe. This landscape was rich in sedges, docks and mugworts that played a major part in feeding the large herds of Reindeer and the Giant Irish Deer that had followed the new vegetation northwards. One of the few plants that survived this first major transition in Ireland’s flora is the Mountain Avens, an unmistakable flower of the arctic, that has managed to survive and thrive in a few limestone and upland areas like the Burren. While the Mountain Avens is what most of us would call a wildflower, this member of the rose family is classified as a shrub which is reflected in its Latin name, Dryas octopetala. The dryas are ancient Greek tree nymphs or tree spirits. This part of the name was eventually passed on to the geological epochs of the Younger Dryas and the Older Dryas, the time periods where Dryas octopetala was particularly widespread. The second part of the name draws attention to the eight petals of the Mountain Avens’s flower.
Around 11.000 years ago the Nahanagan cold snap pushed many plants and animals back south for a while but with a rapid rise in temperatures that started around 10.000 years ago the flora with the fauna in its tow started to recapture the lost territory. Continuously rising temperatures allowed for a swift change in Ireland’s landscape. Some 10.500 years ago the Birch was the first tree to establish itself and laid the foundation for other species to follow. Birch trees carry fruit after only 10 years and so started to form forests within a few decades. In addition the shed leaves made a major contribution to the developing soil every autumn. Hazel arrived shortly after the Birch together with it a number of herbaceous plants that are still associated with forests today.
The Primrose is one of those, although today it isn’t limited to a forest setting and can be found in a number of habitats like hedgerows, roadsides and even exposed coastal areas. The Primrose is one of the first flowers to burst into bloom every year. Its Irish name sabhaircin means May flower, but nowadays this quintessential spring flower starts to show its first blossoms on average in March, sometimes as early as February. The flowers of the Primrose come in two different forms on each plant. The pin flowers show a prominent style while in the thrum flowers the style is considerably shorter and the stamens are the dominant part of the flower. This ensures cross-fertilization which means it is more likely that pollinators, for the Primrose those are mainly bumble bees and beetles, transport pollen from one plant to another plant. Soon after the Primrose the Wood Anemone bursts into bloom and another few weeks later Bluebell, Wild Garlic, Cuckoo Pint, also known as Lords and Ladies, and others follow. Like the Primrose these flowers are not limited to woodlands anymore and can be found in other habitats. Their presence however often indicates the former existence of a forest at their present location.
These plants, even if they now grow in the open, have kept their habit of flowering early. In a forest setting this early start was necessary to finish the process of growing, flowering and producing seeds before the forest canopy closed and cast the forest floor in permanent twilight. The need of light becomes especially obvious in the Lesser Celandine and Wood Anemone. Their delicate flowers only open fully in sunshine and stay closed on cloudy days. Strangely enough the flowers of the Wood Anemone rarely produce fertile seeds and the plant spreads mainly by expanding its root system, a reproductive procedure quite a few flowering plants use in addition to producing seeds.
Once the trees have awoken from their winter slumber the forest floor soon gets cast in shadow and the spring flowers take a rest. After spreading their seeds, the Primrose slowly disappears from the surface and reverts its energy reserves into its root and the Bluebell does the same with its bulb. The Cuckoo Pint is one of the few that keeps a presence above ground. Arranged around its stem, a cluster of berries turn from green into a bright red over the course of the summer.
How this flora made its way to Ireland is still a matter of debate. It is accepted that for a limited period of time land bridges existed between the European continent and the islands of Britain and Ireland and that plants and animals used these connections to move from the continent first to Britain and then into Ireland. As these migration highways disappeared under the rising sea, Ireland was the first island to become isolated from the continent. The number of species that made it all the way to Ireland stayed relatively small and consequently Ireland hosts only around 800 species of flowering plants while its neighbour Britain has almost twice as much.
This shouldn’t be surprising, what is however an unexpected mystery are certain plants that grow in Ireland but not in Britain. The Lusitanian Flora is a group of 15 species that thrive in northern Spain and Portugal as well as in Ireland but none of those plants can be found in Britain. How plants like the Strawberry Tree, Maidenhair Fern, Large Flowered Butterwort and Irish Fleabane to name but a few found their way to Ireland is still not entirely clear. Some theories suggest a land bridge between the Iberian Peninsula and Ireland, others think that seeds were carried in ocean currents or that the Lusitanian species were introduced accidentally and much later by trade between Spain and Ireland. An alternative theory, and one that gains ever more traction, and which could also be applied to many other species, suggests that these plants have been in Ireland since before the ice age and managed to survive in some hidden corners of the southwest, riding out the glaciation periods as seeds and reproducing in the warmer periods in between.
Over time Birch and Hazel were joined by bigger forest trees, first and foremost oaks and pines and eventually the open grassland was transformed into vast forests. The extent of these forests is currently a matter of debate. The classic scenario and the one featured in the natural history books is a country covered in woodland from coast to coast. Current pollen analysis however gave rise to the theory that Ireland featured a more open landscape where grassland interspersed with large forests.
The first people that arrived in Ireland, Mesolithic hunter-gatherers that lived on a diet of fish, shellfish, fruit and nuts, stayed close to the coast and didn’t venture much into Ireland’s interior. During their reign the Irish landscape didn’t change much. The transformation of the land was coming with the arrival of Neolithic farmers some 6000 years ago. Since then, Ireland’s landscape and its flora have experienced a radical change.
In the beginning these changes were small and happened gradually. The Neolithic farmers created clearings in the forests to build their farmsteads and transformed wild grasslands into pastures and fields, today known as semi natural grasslands. Wild grazers like deer and elk were replaced by cattle, goat and sheep and suitable wild plants were cultivated to grow bigger and yield more fruit and seed. With a growing human population, the number and size of farmed areas increased steadily, and over time the Irish landscape was turned into the checkerboard of fields and pastures we see today.
The semi natural grasslands created by the early farmers were made up of some 250 species of flowering plants. These species formed communities depending on local climate, soil type and drainage condition and it wouldn’t have been unusual to find more than 40 species within a few square meters. Today these grasslands are divided into four main categories: Wet meadows, dry meadows, roadside grassland and upland meadows. These environments often blend together, sometimes even in the same field and can so host a multitude of different species. The majority of the angiosperms in a meadow are grasses. Worldwide there are more than 11.500 known species of grasses including our cultivated food stables of Wheat, Rye, Oat, Corn and Rice, and agrostologists (Agrostology is the study of grasses) estimate that there could be a total of up to 13.000 different species. One of the most common species in Ireland is Red Fescue which can tolerate a range of soil conditions, Marsh Foxtail is an indicator for wet ground, Quaking Grass prefers it well drained and dry, Sweet Vernal grass is typical for acidic soils and Yellow Oat Grass is an indicator for alkaline soils.
The wind pollinated grasses grow side by side with variety of meadow flowers like Common Knapweed, Oxeye Daisy, Red and White Clover, Bird’s Foot Trefoil, Ragged Robin, Devil’s Bit Scabious, various orchids, and others. These grasses and herbs thrived not despite but because of the interference of farming. Carefully timed grazing and cutting allowed the herbaceous species to flourish beside the grasses and the droppings of the farm animals provided fertilizer and supported the regeneration of the soil. This way of farming very much reflected the natural way of things that allows a wide variety of plants and animals to thrive.
The best known of the semi natural grasslands is the traditional hay meadow, a dry grassland that can be found on calcareous and well drained soils. The meadows of the Burren National Park are a good example for this kind of grassland. Its counterpart the wet meadow often lies on the floodplain of a river or beside a lake that experiences fluctuating water levels. The Shannon Callows are a prime example for a wet meadow. A unique kind of grassland and one of the rarest habitats in Europe that can only be found in the west of Ireland and parts of western Scotland is the Machair. Machair is the Gaelic word for fertile plain and these low lying, coastal grasslands are always adjacent to a beach or dune system. The ground that forms the Machair is highly calcareous and consists mainly of shell fragments that have made their way from the sea onto the beach and eventually inland, being broken down into ever smaller particles along the way. In summer the Machair turns into a colourful carpet consisting of Pyramidal Orchid, Ox-Eye Daisy, Bird’s-Foot Trefoil, Lady’s Bedstraw, White Clover, Harebell and others and rivals any hay meadow in appearance.
While all these grasslands were never truly natural, they formed a species rich environment where various plants, insects, birds existed in relative harmony and balance with men. Today unfortunately these grasslands have mostly disappeared from Ireland. The old farming practice of hay making, which in fact isn’t that old and only came into being around 1000 years ago, involved one cutting in late summer and tedious stacking and drying of the bounty. This labour intensive and in the wet Irish climate often futile practise has been replaced by silage, the cutting and immediate wrapping of the crop into plastic sheets. The new technique was a much safer and quicker option for the farmer to secure winter fodder for the animals, but silage was also the start of a downward spiral for the biodiversity of the species rich grasslands. A growing national herd demanded more food and so the old meadows with their mixture of grasses and herbs were replaced with fast growing rye grasses. At the same time chemical fertilization was introduced to allow two or even three cuts over the summer. The result are beautifully green but otherwise barren pastures. Where once 30 or more species thrived in a field, one might be lucky to find 10 today. The loss of plant diversity is however only the tip of the proverbial iceberg. Apart from the wrapping plastic that has turned into a pollution problem in itself and the run-off of fertilizer that causes additional environmental problems, modern farming has also displaced many ground nesting birds. The nests and their inhabitants that aren’t being destroyed by farm machinery are an easy pick for predators. The corncrake is probably the most famous but not the only victim of modern farming and has disappeared from most of its traditional breeding grounds and is close to extinction. Another and more far-reaching side effect of the modern monocultures and use of chemicals is the decline in insect populations and therefor a loss of pollinators. In recent years not only the much-loved bees and butterflies have dramatically dropped in numbers, the not so much loved but nevertheless important flies and other creepy-crawlies are in sharp decline as well.
The loss of wildflowers also means a loss of knowledge and wisdom that had been acquired over generations. Many of the plants that have been declared unwanted weeds have medicinal properties, were used as food or for other applications in the home and the farm. Lady’s Bedstraw for example was once widely used as a rennet in cheese making, the flowers were made into a drink and the roots were used for dye. Red Clover was a welcome ingredient for salads and used for wine making. The developing seed heads of the White Clover were ground into a flour and used for baking; timing however was important because the fully developed seed heads are poisonous. Meadowsweet, which today can mainly be found at roadsides and in ditches, has been used as an anti-inflammatory, antiseptic, analgesic and diuretic. The dried leaves have been eaten as sweet treat, the flowers made into cordial and the roots were the source for a black and yellow dye. The Primrose was well known as a remedy for cuts, bruises and other skin conditions and Cowslip, which has a narcotic effect, was used as a cure for insomnia and also was made into wine. Yarrow was a common medicine for arthritis and rheumatism and was taken in the form of a tonic, potion or tea. The humble Daisy is rich in vitamin C and despite its bitter taste was often used in salads and the Cuckoo Flower was known as an antispasmodic… the list could go on.
Today the old-style meadows have only survived in protected areas and make a bit of a comeback on some organic farms. While the disappearance of the hay meadow was the most visible loss in the Irish landscape, flowering plants in other habitats were also decimated. The drainage of the peatlands meant the end for numerous species, heavy grazing in mountainous regions put huge pressure on plants there and manicured gardens drenched in pesticides not only eliminate native plants but insects and other invertebrates with them.
Climate change is also having a big impact on flowering plants, both positive and negative. While some species have been known to flower throughout the year, especially in the mild climate of the west coast, more and more wildflowers abandon their traditional flowering time in exchange for a rather erratic behaviour. Some species start to bloom several weeks earlier than usual while others produce flowers in irregular intervals throughout the year. In my little corner of Ireland I see typical coastal flowers like Thrift and Sea Campion appear up to two months before their usual time, sometimes as early as late January. Others like Daisy and White Clover produce flowers whenever they see fit, even in the middle of winter, and gardeners tell anecdotal stories of their roses suddenly bursting into bloom in November and strawberries bearing fruit at Christmas. For flowers and insects that have formed a close relationship this can have dire consequences. The insects will experience a lack of food, because by the time they arrive on the scene the flowers would have already faded while the flowers wouldn’t have been able to produce seeds because their pollinators were still in hibernation.
A warming planet will also change the makeup of plant communities. Arctic and alpine species might have to move further north or to higher altitudes to survive. Mediterranean species on the other hand would be able to extend their reach and there are already signs that some species move northwards and conquer new ground.
It is however also possible that over time flowers and insects will adapt to a new timetable and that alpine and arctic species will find a way to adapt to the warmer temperatures, like the Mountain Avens must have done in the Burren, and live side by side with species built for warmer climates. In the end adaption is what evolution is all about.
Nevertheless, wildflowers today live on borrowed time. National parks and nature reserves, some ditches and roadsides, coastal fringes and hard to reach mountain tops are the only places left where wildflowers can still thrive. Bringing wildflowers back however would not be difficult. Because these plants can produce seeds within a few months, wildflowers would come back very quickly if we would only let them. Some County Councils have already stopped mowing roadsides and roundabouts every other week and movements like We are the Ark guide garden owners in transforming their landscaped backyard into a more natural place. If every garden owner would give back a part of their property to nature and let the native flora take over or re-introduce long gone wildflowers, it would be a big, first step back from the brink of a world without flowering plants and all the consequences this would bring.
Carsten Krieger, October 2021