German Plant Community 2023: Littorelletea uniflorae p.p.

Habitat of nutrient-poor shallow water

The Floristic-Sociological Working Group declared the highly threatened Littorelletea uniflorae p.p. as the German plant community 2023. They were formerly quite common in the vicinity of clear, shallow heathland pools on sandy and gravelly raw soils or peaty substrates – inconspicuous and well adapted to the special requirements of the amphibious habitat.  Due to human interventions such as nutrient inputs and drainage, as well as the consequences of climate change, Littorelletea uniflorae p.p. is now highly endangered. Many of their habitats have already been lost or significantly reduced. Due to their rarity and need for protection, Littorelletea uniflorae p.p. has also been included in the Fauna-Flora-Habitat Directive of the European Union.


The plants live near the shore, in a narrow strip between reed beds and deeper water, completely submerged or periodically dry. Water level fluctuations support the development of Littorelletea uniflorae p.p. The plant community is named after the European shoreweed Littorella uniflora (also known as Plantago uniflora depending on taxonomy). It is accompanied by the even rarer delicate white-flowered water lobelia Lobelia dortmanna and the lake quillwort Isoëtes lacustris, which belongs to the quillwort family and is already extinct in parts of Germany (Bavaria and Baden-Württemberg). However, the plant community also includes more commonly found species such as bulbous rush Juncus bulbosus or marsh pennywort Hydrocotyle vulgaris.


The dominant representatives of this group of plants are also classified as low-growing basic shoot plants (Isoëtes). They all share a strong and enduring basal rosette of narrow leaves with well-developed aerenchyma, which is air-conducting tissue. This adaptation to life in water allows the storage of air in the tissue, giving the leaves buoyancy. This growth form enables the plants to withstand seasonal, pronounced water level fluctuations: longer flooding in the winter months, but also enduring dry periods in late summer.

Finding Littorelletea uniflorae

Fluctuating water levels in very nutrient-poor stagnant waters are rare in Germany, and in combination with the inconspicuous appearance of most species, stumbling upon a population of Littorelletea uniflorae p.p. is highly unlikely. Interestingly, there are old reservoir structures in the heart of Germany where you can find them easily. In the Upper Harz region, in the Clausthal-Zellerfeld area, about 65 dams and water bodies were created between the 16th and 18th centuries. 35 of them are classified as reservoirs and are now operated with fluctuating water levels for nature conservation reasons, long after the end of their economic use. Here, extensive Littorelletea uniflorae p.p. can be found, as well as the equally rare dwarf rush communities with sea strapwort Corrigiola litoralis, Illecebrum verticillatum, or water mudwort Limosella aquatica. If you find Littorella uniflorae p.p., you can collect the badge for the plant community 2023!

For more information, visit the Floristic-Sociological Working Group website:


This article was featured in the Flora-Incognita app as a story in the summer of 2023. The app provides intriguing information about plants, ecology, species identification, as well as tips and tricks for plant identification. Why not take a look?

German Poisonous Plant of the Year 2023: Parsley

A poisonous kitchen herb?
Every year, the Botanical Special Garden Wandsbek in Hamburg announces the German Poisonous Plant of the Year. After the potato in the previous year, for 2023, it is parsley (Petroselinum crispum). The choice of parsley as the Poisonous Plant of the Year is intended to remind us that even seemingly harmless plants can have their dangers. It is important to be aware of the potential risks and side effects of plants and to use them only after careful research.
Dangerous parsley?
Parsley is a biennial plant that initially forms the well-known, low, basal rosette, which is indispensable in many kitchens. In the second year, the plant develops up to 70 cm tall flowering stems that bear inconspicuous yellowish-green flowers. Toxic seeds develop from these flowers. The seeds contain parsley oil, which contains the phenylpropanoid apiol. Consuming it in high doses can lead to allergic reactions and even liver, heart, and kidney damage.
There’s a badge!
If you identify a parsley plant with your Flora Incognita app this year, you will receive the ‘Poisonous Plant of the Year 2023’ badge for your profile!

This article was featured in the Flora-Incognita app as a story in the summer of 2023. The app provides intriguing information about plants, ecology, species identification, as well as tips and tricks for plant identification. Why not take a look?

Phenology: Midsummer – Long Days, Warm Nights

When we think of midsummer, we might hear the buzzing of insects, the chirping of birds, or the joyful laughter of children fully enjoying their summer vacations. Midsummer brings us a plethora of outdoor activities and unforgettable moments that will hopefully stay with us for a long time. However, climate change does not spare changes in nature. It is crucial to document specific key points every year to make these changes visible. So, let’s take a closer look at what characterizes the phenological midsummer:

Linden Trees in Bloom

The blossoming of linden trees marks the beginning of midsummer. To differentiate them from winter linden trees, you can examine the leaf hairs: the summer linden has small white hairs on the entire underside of the leaves and on the branches, while the winter linden is only hairy on the veins and in the vein angles on the underside of the leaves. Linden flowers can be collected for tea, and due to their high sugar content in nectar, they are also an essential late food source for many insects.

Ripening of Currants

Ripe currants are the first sweet summer fruits that can be “wildly” harvested in Central Europe. However, modern cultivated varieties are no longer identical to the original Ribes rubrum. To enhance the aroma and optimize cultivation, other currant species were crossed (or the color: White currants are just a color variant of the red ones). Black currants (Ribes nigrum), incidentally, are closer relatives to gooseberries than to red currants and ripen slightly later, depending on the cultivation. The bushes of black currants have a smell that some find “unpleasant.” Nevertheless, an important perfume extract is obtained from the flower buds!

Harvesting Sweet Cherries

Sweet cherries (Prunus avium), also known as bird cherries (the species name reveals it!), belong to the rose family. Particularly popular among children and those with a sweet tooth are the well-known cultivated forms, such as the heart cherry (Prunus avium subsp. juliana), because the wild form Prunus avium L. subsp. avium has tiny, black, and bittersweet fruits. It typically thrives in oak-hornbeam mixed forests and can grow up to over 20m in height. The ripening of cultivated sweet cherries is a significant indicator of midsummer. In 2021, Germany recorded 27,340 tons, Austria 6,210 tons, and Switzerland 4,415 tons of harvest – for comparison: Turkey leads the list of the world’s largest sweet cherry producers with an annual production of 689,834 tons.

Barley Harvest Time

Barley (Hordeum vulgare) belongs to the grass family (Poaceae). With an impressive cultivation history of around 10,000 years, it is one of the cornerstones of European agriculture. Winter barley plays a significant role in phenology. Sown in autumn, it thrives initially in a pleasant 10°C and is often the first crop harvested from the fields, even before other cereal crops. This harvest time is another indicator of midsummer. In Germany, winter barley is cultivated on approximately 1.24 million hectares, while spring barley thrives on only about 0.5 million hectares. Overall, Germany harvests about 10 to 12 million tons of barley annually.

This article was featured in the Flora-Incognita app as a story in the summer of 2023. The app provides intriguing information about plants, ecology, species identification, as well as tips and tricks for plant identification. Why not take a look?