Diversity of life – Habitat diversity

Biodiversity – The Series

The three main aspects of biodiversity are species diversity, the genetic diversity of a species and the diversity of habitats in a region. We cover all those aspects in dedicated articles. In this one, we take a closer look at how important it is to have multiple habitats in a given area.

What does habitat diversity mean?

Habitat diversity is a metric of how many different habitats are present in a given area. For example, an area where a naturally flowing stream separates a woodland fringe from a meadow may have a high structural diversity. A large arable field without hedges or wildflower strips, on the other hand, does not have a high diversity of habitats. A high diversity of habitats automatically increases the species diversity of the area, as each of these biotopes has its own biocoenosis and therefore a single area can be colonized by more species.

Loss of habitats

Humans bear the main responsibility for the destruction of habitats through the use of natural resources, air, light and water pollution, noise pollution, intensive agriculture, industrial production and the progressive urbanization of landscapes. Other influential human activities include mining, deforestation and trawling. Eutrophication, the excessive input of nitrogen and phosphorus into ecosystems and the atmosphere, has a global impact. In the long term, this nutrient input leads to nutrient-poor habitats losing their unique and species-rich character and becoming increasingly similar to other locations.

However, abiotic environmental factors can also (indirectly) contribute to the destruction of habitats. These include geological processes such as volcanism, climate change, and the spread of invasive species.

Invasive species take over habitats

Habitat destruction in an area can lead to a shift in local biodiversity from a mix of generalists and specialists to a population consisting mainly of generalists. Invasive species are often generalists because they can survive in a much wider variety of habitats than specialists. If these invasive species, which are particularly prolific, colonize ever larger habitats in an area, there is less and less room for the few specialists originally native to the area. As a result, the so-called extinction threshold of the specialists shifts ever further into a fatal direction – and the probability of their extinction increases.

Loss of biodiversity

Habitat destruction is the biggest driver of species loss and the loss of genetic diversity within species. And this is not just about the loss of large and popular animals such as the giant panda. Species such as nematodes, mites, earthworms, fungi and bacteria carry out many of the processes that are essential to human life, such as purifying air and water, and they too disappear when their habitats are destroyed. At a higher level, plants not only provide structural diversity and protection against erosion, but also energy and nutrients, which are then processed by other creatures in the food chain.

Example: Deadwood

A “well-tended and tidy” (managed) forest is often one from which wood is harvested before it can die. However, this means that the forest habitat is missing something that was originally an integral part and has been able to develop and optimize itself over thousands of years – a hotspot of biodiversity: under the bark of dead trees, starch, sugar, vitamins, proteins, amino acids and cellulose are waiting to be decomposed by longhorn beetles and bark beetles, wood wasps and thousands of often highly specialized insects and fungi. Their bore dust, excrement and moulting residues attract new wood colonizers – by the way, different ones in lying than in standing dead wood. Bats, owls and dormice use dead wood as a hibernation camp or roost, while other organisms – plants, fungi, woodlice, mites and worms – complete the decomposition process. What remains is a large amount of humus, the perfect basis for new growth.


The example of deadwood shows impressively that countless habitats and processes have already been changed and destroyed so quickly by humans that entire groups of organisms have become extinct or their survival is acutely threatened. However, knowledge of the interrelationships and daily efforts to preserve and restore habitats can make the difference between preserving a diversity of habitats, of species and the diversity within these species in your own town, village or garden.


This article was featured as a story in the Flora-Incognita app in spring 2024. In this plant identification app, you can find exciting information about plants, ecology, species knowledge, and tips and tricks for plant identification. Check it out!

Diversity of life – Genetic diversity

Biodiversity – The Series

The three main aspects of biodiversity are species diversity, the genetic diversity of a species and the diversity of habitats in a region. We cover all those aspects in dedicated articles. In this one, we take a closer look at the aspect of genetic diversity.

Genetic diversity

A species consists of individuals that are very similar but have small differences in their genetic information. If there are many of these small differences, then this species has the potential to adapt easily to new environmental conditions. For example, if some individuals in a population have the ability to reproduce despite high soil moisture and other individuals have the ability to do so in dry conditions, then the species is likely to survive even if the site conditions change.

Not all genes are always active

On average, around 30,000 genes are active in plants at different times and under changing conditions. Whether and how well a plant thrives, to what extent it can adapt to its environment and cope with climatic changes, therefore depends on how large the pool of genes that can be activated is. If we look at a single gene, its activation depends, among other things, on where and how the plant lives: Individually? In a dense population? In full sun or in the shade? Aspects such as moisture or the chemical composition of the soil also play a role.”

Not all individuals have to adapt

There are also plants that can even activate genes to send out “calls for help”. For example, they then produce scents that attract predators to eat pests. Experiments by scientists at the Max Planck Institute for Chemical Ecology have [shown](https://elifesciences.org/articles/04490) that it is sometimes sufficient for only individual plants within a larger population to develop this genetic trait in order to protect all neighboring plants.”

Diversity as the basis for evolution

Genetic diversity within a species is also the basis for the formation of completely new species. There are various concepts for this, which differ mainly in whether or not there is a spatial separation (through mountain and island formation, storms) of populations.

  • If this is the case, there can no longer be any genetic exchange between the groups and new species will eventually emerge through mutation and selection.
  • Species formation without spatial separation: due to spontaneous mutation of the reproductive organs, individuals can no longer reproduce among themselves. The altered population splits off from the original species.
  • Species formation despite gene flow: As shown at the beginning of the story, high genetic variability within a species can ensure that it can thrive in completely different locations. Over long periods of time, the smallest changes ultimately ensure that new species have emerged from these adapted populations


This article was featured as a story in the Flora-Incognita app in spring 2024. In this plant identification app, you can find exciting information about plants, ecology, species knowledge, and tips and tricks for plant identification. Check it out!

Diversity of life – Species diversity

Biodiversity – The Series

The three main aspects of biodiversity are species diversity, the genetic diversity of a species and the diversity of habitats in a region. We cover all those aspects in dedicated articles. In this one, we take a closer look at the aspect of species diversity.

Species diversity

The term species diversity describes the number of biological species in a given area. This applies to small areas as well as large ones: a single tree in the Amazon, an entire mountain range, a political state, or even just a grid cell in a city. Typically, the species diversity of such an area is divided into specific groups such as plants (or just trees), mammals, fish, insects – depending on the question or topic.

How many species are there?

In 2006, around 2 million species were scientifically described. This contrasts with estimates of 5 to 20 million species that actually exist worldwide. It is very difficult to give precise figures for these two, as different groups of organisms have different criteria for species delimitation, and modern classification methods also include genetic information. There are also a large number of synonyms, and most species are very small and live in areas that are not easy to reach. Nevertheless, around 12-13,000 new species are scientifically described every year.

Why is species diversity important?

Nature is crucial for our survival as it provides us with important ecosystem services such as food, medicines, water regulation and recreational opportunities. It also helps to regulate the climate, and each species plays a unique and important role. The absence of a species can lead to the disruption of complex ecological cycles. For example, the extinction of insect species can have a negative impact on birds that feed on these insects and on the pollination of plants (including crops).

What threatens species diversity?

First and foremost is the destruction of habitats through construction, clearing, or modification, e.g., through intensification of soil cultivation. Many species-rich habitats are nutrient-poor, as a few dominant species spread quickly on nutrient-rich sites. The input of nitrogen and phosphorus from pollutants poses a threat to these habitats. Finally, invasive species can also have a lasting impact on existing ecosystems by disrupting the complex interactions between the species that occur there and successfully displacing established species. Above all these factors is climate change, which is altering many established processes so rapidly that the adaptability of many species cannot keep pace.

How can species diversity be protected?

Restoring or maintaining diverse habitats is the most important measure for preserving species diversity – or at least slowing its decline. Examples include restoring floodplain landscapes along rivers, allowing standing and lying deadwood in forests, thinning dry grasslands, extensive year-round grazing, flowering strips with native wild herbs and shrubs on agricultural land and stopping the drainage of moors. But our own actions can also have an influence: Wild corners in the garden, partially mowing of meadows, use of peat-free soil, participation in work to remove invasive plants or political and educational work are valuable building blocks for the preservation of species diversity.


This article was featured as a story in the Flora-Incognita app in spring 2024. In this plant identification app, you can find exciting information about plants, ecology, species knowledge, and tips and tricks for plant identification. Check it out!

Diversity of life – Biodiversity

Biodiversity is not the same as species diversity

Biodiversity is a term you read in many places, but what exactly does it mean? In simple terms, biodiversity is the variety of life on earth. Many people use the term species diversity as a synonym for biodiversity, but this falls short. High biodiversity not only refers to the fact that there are many species of living organisms (e.g. animals, plants, fungi), but also to the fact that there is great genetic diversity among them. There is also a third component: the diversity of habitats. To explain these three forms of biodiversity to you in more detail, more Flora Stories will follow in the coming weeks, which will take a closer look at the individual forms. Don’t miss them!

Loss of biodiversity

In May 2019, the Global Assessment Report on Biodiversity and Ecosystem Services was published. The report highlights the alarming state of global biodiversity. Data from 1970 to 2018 for a total of 31,821 populations of 5,230 species from all over the world show that the population sizes of the observed mammals, birds, amphibians, reptiles and fish have shrunk by an average of 69 percent. The main reason for this is the loss of diverse habitats. The ever-shrinking populations inevitably lead to a loss of genetic diversity. This is why it is so important to protect or restore habitats. This is precisely the motto of this year’s Biodiversity Day.
Biodiversity Day (May 22)
International Biodiversity Day is celebrated every year on May 22. In 2024, the motto is ‘Be part of the Plan’. This motto is a call to action to stop and reverse the loss of biodiversity, because every human being interacts with the environment and can become part of the plan to conserve biodiversity.
Badge: Biodiversity Day
Flora Incognita was developed to make it easy for you to get to know plant species. Only those who know species can protect species! That’s why you can earn the Biodiversity Day badge on May 22nd. All you have to do is identify a variety of different plant species on this day with Flora Incognita. There are three levels: for 10, 20 and 30 different species. Have fun with this task!

This article was featured as a story in the Flora-Incognita app in spring 2024. In this plant identification app, you can find exciting information about plants, ecology, species knowledge, and tips and tricks for plant identification. Check it out!

A closer look at flowers: thermoregulation in winter

In winter or in cold habitats such as high mountains, an optimal flower temperature is important for successful reproduction. Some plants can actively produce heat in their flowers, such as Helleborus foetidus, using yeast bacteria in the nectar (Herrera and Pozo, 2010). But this is the exception. For most plants in cold regions (or early bloomers), the more heat they can absorb from the environment, or at least not lose, the better. In this story you will learn what influence characteristics such as shape, colour, pubescence or orientation to the sun have on the temperature in the flower.

Bells and discs
Have you ever wondered why many early bloomers have bell-shaped flowers? The answer is that bells collect more heat than disc-shaped flowers. Hanging bells can absorb heat from the ground radiation and so the temperature inside the flower lies 3-11 °C above the ambient temperature (Kevan, 1989). Upright bells, such as gentians, bundle the sun’s rays when they fall at a certain angle. In disc-shaped flowers, the reproductive organs are directly exposed to the environment and are located in the centre, where most of the incoming light is reflected by the flower. But the petals also play a role. In one experiment, the excess temperature in Saxifraga oppositifolia flowers was reduced by 70% compared to the surrounding area after removing the petals (Kevan, 1970).

Another successful strategy is the formation of “micro-greenhouses”. These are, for example, bubble-shaped structures made of translucent bracts, as in the yellow rattle (Rhinanthus minor), or sepals, as in Physalis. These filter light in the UV range, but allow longer wavelengths to pass through, which heats the air inside. Similar to flowers, hollow stems can also have a heating effect if the heat trapped in the stem leads to an increase in internal temperature (Kevan et al. 2018, 2019). This can promote the development of the flower bud immediately above it.

Orientation towards the sun (heliotropism)
During the course of the day, some plants permanently orientate their flowers so that they face the sun. In cold regions in particular, this leads to effective warming of the flower. This can have advantages for the plant, for example through increased temperatures in the reproductive organs, heavier seeds and more visits from pollinators. Many experiments have already tried to demonstrate the added value of heliotropism, but not always successfully. (Van der Kooi, 2019).

Darker colours can absorb more solar radiation. This can be converted into heat, which can increase the temperature of the flower. In a series of experiments with Plantago, a close relationship was found between the colour of the flower-bearing inflorescence and its temperature. Individuals developing at low temperatures produced darker panicles that were 0.2-2.6 °C warmer in direct sunlight than the comparison group (Anderson et al., 2013). Another study found that purple-coloured flowers of Ranunculus glacialis were warmer and produced more seeds than white-coloured flowers of the same species (Ida & Totland, 2014). However, there are also studies in which the colour of the flower has no influence on the flower temperature (Van der Kooi, 2019). Further studies are needed to better understand the relationship between flower colour, temperature and reproductive capacity.

Opening and closing
The opening and closing of flowers through petal movement is widespread throughout the plant world. In particular, cup- or disc-shaped flowering species protect themselves from external factors such as light, moisture or temperature in this way. Opening and closing can take several minutes or hours, depending on the species. It is assumed that closing the flower protects the pollen from precipitation (washing out, damage) or drying out, which increases its viability. There are various experiments that have investigated the influence of flower closure on the temperature inside the flower: For example, if the bracts of Tulipa iliensis close at cool temperatures, a more constant temperature is maintained inside the flower (Abdusalam and Tan, 2014).

The pubescence of flowers is probably important for maintaining flower temperature, but in contrast to leaf pubescence, this has been little studied to date. Plant species that grow in high-altitude, cold regions sometimes develop thick leaf pubescence. This creates an insulating boundary layer to the neighbouring cold air mass, which reduces heat loss (Meinzer and Goldstein, 1985). The pubescence of the flowers can have a similar insulating effect as in the example of willow catkins: In Alaska, it was investigated that it can be 15-25 °C inside willow catkins at an air temperature of 0 °C. If the woolly hairs were removed, the internal temperatures in the catkins fell by around 60% (Krog, 1955).

• Herrera CM, Pozo MI. 2010. Nectar yeasts warm the flowers of a winter-blooming plant. Proceedings of the Royal Society of London B 277: 1827–1834.
• Kevan PG. 1989. Thermoregulation in arctic insects and flowers: adaptation and co-adaptation in behaviour, anatomy, and physiology. Thermal Physiology 1: 747–753.
• Kevan PG, Nunes-Silva P, Sudarsan R. 2018. Short communication: thermal regimes in hollow stems of herbaceous plants—concepts and models. International Journal of Biometeorology 62: 2057–2062.
• Kevan PG, Tikhmenev EA, Nunes-Silva P. 2019. Temperatures within flowers and stems: possible roles in plant reproduction in the north. Bulletin of the NorthEastern Science Centre of the Russian Academy of Sciences, Magadan, Russia 1: 38–47.
• Casper J van der Kooi, Peter G Kevan, Matthew H Koski, The thermal ecology of flowers, Annals of Botany, Volume 124, Issue 3, 16 August 2019, Pages 343–353,
• Anderson ER, Lovin ME, Richter SJ, Lacey EP. 2013. Multiple Plantago species (Plantaginaceae) modify floral reflectance and color in response to thermal change. American Journal of Botany 100: 2485–2493.
• Ida TY, Totland Ø. 2014. Heating effect by perianth retention on developing achenes and implications for seed production in the alpine herb Ranunculus glacialis. Alpine Botany 124: 37–47.
• Abdusalam A, Tan D-Y. 2014. Contribution of temporal floral closure to reproductive success of the spring-flowering Tulipa iliensis. Journal of Systematics and Evolution 52: 186–194.
• Meinzer F, Goldstein G. 1985. Some consequences of leaf pubescence in the Andean giant rosette plant Espeletia timotensis. Ecology 66: 512–520.
• Krog J. 1955. Notes on temperature measurements indicative of special organization in arctic and subarctic plants for utilization of radiated heat from the sun. Physiologia Plantarum 8: 836–839.
• Kevan PG. 1970. High arctic insect-flower relations: the inter-relationships of arthropods and flowers at Lake Hazen, Ellesmere Island, N.W.T., Canada. PhD Thesis, University of Alberta, Canada.

This article was featured as a story in the Flora-Incognita app in winter 2024. In this plant identification app, you can find exciting information about plants, ecology, and species knowledge, as well as tips and tricks for plant identification. Check it out!

Winter jasmine or forsythia?

“So early this year!”
Every year from Christmas onwards, we receive messages that the “forsythia is blooming particularly early this year”. No wonder, as its yellow flowers shine particularly beautifully in the gray dreariness (of our towns and villages) – but beware! The shrubs often catching the eye in December and January are (usually) not Forsythia (Forsythia × intermedia). They are often winter jasmine (Jasminum nudiflorum). Let’s take a closer look at the differences:

Winter jasmine
It originates from China and was brought to Europe as an ornamental plant. In France, it is already considered to be permanently wild. If its drooping branches touch the ground, they take root – which leads to the shrub growing tangled and dense.
Winter jasmine blooms from the end of December, and frosty days don’t bother the plant much – it constantly produces new flowers on its light green, bare shoots. Hence, the species name: nudiflorum means “naked-flowered”. A closer look at the flower shows that five to six yellow petals have grown together to form a corolla. Unlike many other jasmines, its flowers are not fragrant.

Forsythia hybrids are popular and rich in flowers (but still bare in January, as can be seen in the picture above). They form upright shrubs of up to 3 m in height. In the 1950s, forsythias were starting to flower in April, but due to climate change, the onset of flowering is shifting further and further into March, occasionally as early as February. Their flowers grow tube-shaped, with four zip-shaped, short, fused petals on bare, brown shoots. In addition to the highly cultivated ornamental plants (hybrids) from China, Korea, and Japan, there are several natural species, including one that is native to the Balkan Peninsula in Europe. It flowers in April and is rarely cultivated as an ornamental plant outside botanical collections.

Winter jasmine flowers from Christmas until around March, when forsythia also begins to flower. Winter jasmine forms tangled, drooping shrubs, while forsythia grows upright. The shoots of winter jasmine are green, and forsythia shoots are brown. The 5-6 petals of winter jasmine are roundish and fused together to a corolla, while forsythia has 4 petals fused together in a tube shape.


This article was featured as a story in the Flora-Incognita app in winter 2023/24. In this plant identification app, you can find exciting information about plants, ecology, and species knowledge, as well as tips and tricks for plant identification. Check it out!

Autumn Leaves: What Lies Behind the Explosion of Colors and Rustling Leaves?

Magical Autumn
Green, yellow, red, brown leaves in all transitional phases currently call for long forest walks, providing atmospheric nature experiences and creative inspirations. However, there’s nothing magical behind this: decomposition and substance transport are responsible for the transformation. The aging process is known as senescence, and the eventual leaf fall is termed abscission. Let’s take a closer look at both:

Senescence – the Last Chapter of Phenology in the Year

Genetically controlled and dependent on available energy, leaves age in autumn. They take in less and less CO2 and eventually cease photosynthesis altogether. When the leaves fall to the ground, this is measurable through remote sensing. The so-called “browning,” the brownish appearance of the ground beneath the bare tree, marks the end of the phenological year. But why do deciduous trees shed their leaves?

Leaf Shedding – Threefold Genius

Leaves evaporate large amounts of water, around 300 to 600 liters per square meter of leaf area per year in a beech tree, for example. Roots absorb the necessary water from the soil, which is not possible when it’s frozen. The tree would dry out. By shedding leaves, this flow of water is stopped, and the tree survives the winter unscathed. But there are two more important advantages that come with leaf fall: the environmental toxins accumulated and stored in the leaves are disposed of, and bare trees withstand snow loads better.

The Chemistry of Autumn Colors

The vibrant colors of the autumn forest are present in the leaves throughout the year but masked by green chlorophyll! When chloroplasts, the storage sites of chlorophyll, are transformed into gerontoplasts within cells, chlorophyll breaks down, revealing other pigments. Carotenoids appear yellow-orange, and anthocyanins bring out red tones – incidentally, as a stress response to excessive sunlight. The red pigments act as a shield against intense sunlight and ensure that chlorophyll breakdown occurs in dying leaves even on cold, sunny autumn days.

How Does Leaf Fall Work?

When exactly a leaf falls from a branch depends on various factors. There is a genetic component for each species, but also site characteristics such as altitude, temperature, day length, and wind play a role. Decreasing availability of light and warmth activates phytohormones, and at the end of the leaf stalk, an anatomical process of change occurs: a separation tissue forms where middle lamellae, cell walls, or entire cells dissolve. Eventually, the leaf’s own weight is enough for it to fall to the ground.

This article was featured as a story in the Flora-Incognita app in autumn 2023. In the app, you can find exciting information about plants, ecology, species knowledge, as well as tips and tricks for plant identification. Why not take a look!

Phenology: Late Autumn – Preparing for Winter

Leaf surfaces play a crucial role in plant biology, facilitating the evaporation of water absorbed through roots. The shedding of leaves in autumn prevents them from drying out when frost freezes the water in the soil. Late autumn marks the final phenological season before the period of dormancy, signaled by the changing color of English oak leaves and the shedding of leaves in many other deciduous trees.

Leaf Coloring in English Oak

English oaks (Quercus robur) are found from the North German Lowlands to altitudes exceeding 1000 meters in the Alps. Their habitat extends far beyond Central Europe, reaching into the Caucasus region. As chlorophyll is broken down, revealing other plant compounds (carotenoids impart yellow hues, anthocyanins create red tones, and water-soluble pigments produce brown shades after leaf death), autumnal oak leaves glow in yellow and brown hues.

Rowan Leaf Fall

According to the German Weather Service, the rowan tree (Sorbus aucuparia) shedding its leaves is a key indicator of late autumn. Rowan leaves are alternately arranged on branches and are distinct with leaf stalks and leaf blades. Their vibrant red autumn coloring makes them a popular sight. The tree’s fruits, known as rowan berries, often remain on the tree in clusters throughout winter, providing essential food for songbirds during winter.

A Touch of Green

Late autumn is also marked by the appearance of tender green fields, signifying the emergence of winter crops. Winter wheat, sown in mid-September, germinates within 15-20 days, displaying the first green shoots. However, the elongation growth and leaf development occur in spring.

This article was featured as a story in the Flora-Incognita app in autumn 2023. The app provides fascinating information about plants, ecology, species identification, as well as tips and tricks for plant identification. Feel free to explore!

The Autumn Crocus

The article discusses the autumn crocus, also known as Colchicum autumnale, which belongs to the Colchicaceae family. There are about 100 species in this family, and the autumn crocus is the most well-known member. It blooms with light-violet flowers in late summer to autumn, adding a last touch of color to our meadows. Despite their name, they are often mistaken for crocuses (Crocus sp.), which belong to a different plant family, the iris family (Iridaceae).

The autumn crocus is a herbaceous and highly poisonous plant. It produces one to five flowers from its corm (a type of bulb-like storage organ). The flowers are generally larger, around 20 cm in length, compared to crocuses. One way to distinguish them is by counting the stamens: the autumn crocus has six stamens, while a crocus has only three.

Unlike crocuses, autumn crocuses produce leaves separately from their flowers. These leaves appear in early summer, always without flowers. However, there’s a potential danger of confusion with another plant, wild garlic (Allium ursinum), which is often collected and consumed. To avoid mistaking wild garlic for other plants like autumn crocuses, you can follow specific guidelines to differentiate them. Here’s an article that guides you through on how to differentiate wild garlic, Lily-of-the-valley, autumn crocus, Jack-in-the-pulpit or Solomon’s seal!


The article was displayed as a story in the Flora-Incognita app in autumn 2023, providing users with interesting information about plants, ecology, species identification, as well as tips and tricks for plant identification.

Phenology: Full Autumn

A glance into nature reveals ripe dogwood cherries lying on the ground, and autumn crocuses have faded away. A new phenological season begins: Full Autumn. Perhaps it will bring us a “Golden October” with many warm days, but weather is not an indicator of phenology. Phenology observes the annual developmental cycle of plants, and thus, Full Autumn is defined by the fruit ripening of the pedunculate oak, followed by late pear varieties and grapevines. The highlight is the foliage coloration of the horse chestnut. Full Autumn comes to an end when the leaves of the European beech and pedunculate oak change color and begin to fall. On average, Full Autumn lasts from September 17th to October 19th.


The pedunculate oak (Quercus robur) belongs to the beech family. It is widespread in Europe and tolerates both (short) waterlogging and dry periods. Consequently, it is found both in lowlands and at elevations of up to 100 meters above sea level. In April-May, the pedunculate oak blooms, and by then, its namesake feature becomes apparent: the flowers (and later the acorns) are borne on 4-6 cm long stalks. Acorns are an important food source for many bird and mammal species (jaybirds, squirrels).

Late Pear Varieties

Comparing apples and pears is rarely a good idea, but one thing can be said: pears (Pyrus communis) need more warmth than apples to unleash their full flavor. Early pear varieties must be consumed quickly and are not suitable for storage. The fruits ripening in autumn can be stored – depending on the variety – well into winter. Classic aromatic pear varieties include Conférence and Gellerts Butterbirne. Among the novelties, the productive variety “David” stands out with firm, sweet, juicy fruits, ripening from early to mid-October.


The grapevine (Vitis vinifera) is the Medicinal Plant of the Year 2023 because its fruits (grapes) are rich in secondary plant compounds. These are mainly concentrated in the seeds of the berries. However, they can also be found in the skin and leaves of red grapes. To determine if a grape is ready for harvest, check if all its berries are colored, the fruit stalks are woody, and the seeds inside the berries are brown, not cream-colored, and easily separate from the surrounding pulp. Grapes are best cut off completely from the vine with scissors and can be stored in the refrigerator for up to 14 days – provided spoiled berries are removed beforehand.

Horse Chestnut

There are several species within the horse chestnut genus, but phenologically interesting is the common horse chestnut (Aesculus hippocastanum). By the way, the sweet chestnut, Castanea sativa, from which delicious chestnuts come, is not related to horse chestnuts! The horse chestnut originates from the mountainous regions of the Balkans and has been widely planted as a street tree in Central Europe since the 16th century. White-flowering horse chestnuts often suffer from infestation by the horse chestnut leaf miner. This leads to premature wilting and dropping of leaves in August to early September. If you want to document the foliage coloration of the horse chestnut as an indicator for phenology, please use healthy trees.

This article was displayed in the Flora-Incognita app as a story in autumn 2023. In the app, you can find exciting information about plants, ecology, species knowledge, as well as tips and tricks for plant identification. Why not take a look!