Erigeron uniflorus aka One Flowered Fleabane

Erigeron uniflorus is a circumboreal arctic-alpine species, native to high latitudes and high elevations across the Northern Hemisphere. Its European range includes the Alps, Pyrenees, Apennines, Carpathians, Scandinavia, Iceland, and parts of the Balkans, with documented occurrences in Austria, France, Germany, Italy, Norway, Finland, Greece, and Bulgaria. In Asia it grows through the Caucasus, north European Russia, Iran, Iraq, Afghanistan, Nepal, and south-central China, and in North America it occurs in northern Canada, Alaska, and Greenland. In Switzerland it is restricted exclusively to the Alps biogeographic region.

Each flowering stem of Erigeron uniflorus bears a single composite flower head, a trait that gives the plant both its species epithet and its common name "one-flower fleabane." The ray florets are slender and white, lilac, or pale pink, surrounding a yellow disk; unlike some related fleabanes, there are no thread-like intermediate florets between the rays and the disk. The cup-shaped involucre below the head is typically tinged red and densely covered in white woolly hairs. Flowering occurs in the short alpine summer, from July to September.

Sexual reproduction via seed. Flow cytometric analysis confirmed that E. uniflorus reproduces sexually and does not produce seeds apomictically. Propagation in cultivation would be via seed sown in cold conditions or with stratification appropriate for high-alpine species.

In nature Erigeron uniflorus grows on open subalpine to alpine grasslands, ridges, and stony slopes on lime-poor, lightly acid to neutral soils, in fully sunny positions and nutrient-poor substrates with moderately dry to moist moisture. To approximate these conditions outdoors, it requires a cool climate, an open and very sunny site, sharp drainage, and a gritty, low-fertility soil typical of rock garden or alpine trough culture. It is not adapted to warm lowland gardens.

GBIF lists three subspecies or varieties as descendants under Erigeron uniflorus L., reflecting some morphological variation across its broad arctic-alpine range. Recognised infraspecific names that have been treated as synonyms or varieties include Erigeron alpinus var. uniflorus Ledeb., Erigeron polymorphus subsp. polymorphus, and Erigeron uniflorus subsp. typicus Á. Löve.

Erigeron uniflorus reproduces sexually, requiring pollination for seed set. Erigeron species are associated with insect visitors, particularly Lepidoptera. In its high-alpine habitat, pollination likely occurs via insects active during the short summer season.

This is a true cold-climate species. Swiss ecological indicator values place it at T=1, meaning the alpine to nival climatic stage, where summers are short and cool and freezing temperatures are common most of the year. It naturally inhabits subalpine to alpine grasslands and ridges and is therefore very cold-hardy but ill-suited to warm lowland conditions.

With a bit of knowledge and dedication, you can successfully care for One Flowered Fleabane, making it a rewarding choice for those seeking a moderate challenge.

New growth will sprout from the top of the One Flowered Fleabane as it grows vertically.

One Flowered Fleabane should be watered regularly, allowing the soil to dry out between waterings.

One Flowered Fleabane loves a well-draining soil. Perlite and vermiculite help with drainage, while coco coir adds organic matter, so a good potting soil mix will have all three. You can improve store-bought soil by adding some perlite to it.

One Flowered Fleabane requires abundant, bright, and direct light to thrive. The best placement for this plant is within one foot of a window to ensure it receives enough light. If you live in an area with more extreme weather, such as hot summers or cold winters, you may need to adjust the placement of the plant accordingly. During hot summer months, it is important to place the plant away from full sun, as this can cause the leaves to yellow or burn. During cold winter months, it is best to move the plant closer to the window to take advantage of the extra light that can help it survive. By keeping an eye on the current weather in your area, you can make sure your Oneflower Fleabane is always in the right place to thrive.

Once the One Flowered Fleabane has doubled in size or after a year has passed, it should be moved to a new pot. By replacing the soil with fresh potting soil containing all the vital nutrients, your plant will receive all the sustenance it needs, negating the requirement for fertilizer. It's important to remember that plants get their energy from the sun, not fertilizer.

No verified data on the toxicity of this plant exists within Ploi's records. Should you, someone in your family, or your pet ingest plant material with an unknown toxicity level, it is recommended to seek medical advice.

During the wintertime, it is common for One Flowered Fleabane plants to go dormant and their growth rate may slow down. Therefore, the amount of waterings should be spaced out more.