Lesser celandine (Ficaria verna) is a flowering plant native to Europe and Western Asia. It has been introduced to North America and is now considered an invasive species. It is potentially fatal when ingested by grazers.
I. Appearance and Characteristics
Ficaria verna (formerly Ranunculus ficaria L.), commonly known as lesser celandine or pilewort, is a low-growing, hairless perennial flowering plant in the buttercup family Ranunculaceae. Native to Europe and Western Asia, it is now introduced in North America, where it is known by the common name fig buttercup and considered an invasive species.
Lesser celandine is a hairless perennial plant to about 25 cm high, growing in clumps of 4-10 short stems, on which the leaves are spirally-arranged or all basal. The leaf stalks have sheathing bases, no stipules, a groove along their upper surface, and two hollows within. The leaves are cordate, 1-4 cm across, dark-green above with a distinctive variegated or mottled pattern, and pale green below. Purple-leaved varieties are common. The margins of the leaves are sometimes entire (rounded) but more often angled or weakly lobed, with hydathodes at the tips. There are two types of roots: dense clusters of thick, pale-coloured elongated tubers surrounded by patches of short, fibrous roots. Some clumps give rise to long stolons to 10 cm or more, allowing vegetative spread to produce extensive carpets of plants.
It produces large actinomorphic (radially symmetrical) flowers, up to 3 (or even 5) cm diameter, on long stalks arising individually from the leaf axils or in loose cymes at the top of the stem. There are no bracts. The flowers have a whorl of 3 sepaloid tepals and 7 to 12 glossy yellow petaloid tepals, which are sometimes tinged purple or grey on the back. Double flowered varieties also occur. The stamens and carpels are numerous, and the fruit is a single-seeded, shortly hairy achene with a very short style. In several subspecies, tubers are formed in the leaf axils after flowering. It blooms between March and May in the UK.
- Life cycle
Lesser celandine grows on land that is seasonally wet or flooded, especially in sandy soils, but is not found in permanently waterlogged sites. In both shaded woodlands and open areas, Ficaria verna begins growth in the winter when temperatures are low and days are short. The plants mostly propagate and spread vegetatively, although some subspecies are capable of producing up to 73 seeds per flower. Germination of seeds begins in the spring, and continues into summer. Seedlings remain small for their first year, producing only one or two leaves until the second year.
Growth and reproduction is poor in dry or acidic conditions, though the plants can handle drought well once dormant. By emerging before the forest canopy leafs out, Ficaria verna is able to take advantage of the higher levels of sunlight reaching the forest floor during late winter and early spring. By late spring, second year plants quickly age as daylight hours lengthen and temperatures rise. By the end of May, foliage has died back and plants enter a six month dormancy phase.
If disturbed, separation of the plant’s numerous basal tubers is an efficient means of vegetative propagation. The plants are easily spread if the prolific tubers are unearthed and scattered by digging activities of some animals and humans. Erosion and flood events are particularly effective means of spread, as the plants are very successful at colonizing low-lying floodplains once deposited.
Ficaria verna exists in both diploid (2n=16) and tetraploid (2n=32) forms which are very similar in appearance. However, the tetraploid types prefer more shady locations and can develop up to 24 bulbils at the base of the stalk. Subspecies F. verna ssp. verna, and F. verna ssp. ficariiformis are tetraploid and capable of colonizing new areas much faster because they produce bulbils in their leaf axils in addition to root tubers. Subspecies F. verna calthifolia and F. verna verna are diploid and hybrids between subspecies often create sterile triploid forms.
- Ecology as an invasive species
In many parts of the Eastern and Northwestern United States and Canada, lesser celandine is cited as an invasive species. It poses a threat to native wildflowers, especially those ephemeral flowers with a spring-flowering lifecycle. Since Ficaria verna emerges well before most native species, it has a developmental advantage which allows it to establish and dominate natural areas rapidly. It is mainly a problem in forested floodplains, where it forms extensive mats, but can occur on upland sites as well.
Once established, native plants are displaced and ground is left barren and susceptible to erosion, from June to February, during the plant’s six-month dormancy phase.
In the United States, where lesser celandine is considered a plant pest to gardens, lawns, and natural areas, many governmental agencies have attempted to slow the spread of this species with limited success. As of 2014, the species was reported to be invasive and established in 25 states. USDA APHIS considers Ficaria verna to be a high-risk weed that could spread across 79% of the United States, anticipating possible impacts to threatened and endangered riparian species.
The U.S. National Park Service’s Plant Conservation Alliance recommends avoiding planting lesser celandine, and instead planting native ephemeral wildflowers such as Asarum canadense, bloodroot, the native twinleaf (Jeffersonia diphylla), and various species of Trillium as alternatives.
- Toxicity
All plants of the buttercup family (Ranunculaceae) contain a compound known as protoanemonin. When the plant is wounded, the unstable glucoside ranunculin turns into the toxin protoanemonin. Contact with damaged or crushed Ficaria leaves can cause itching, rashes or blistering on the skin or mucosa. Ingesting the toxin can cause nausea, vomiting, dizziness, spasms, or paralysis. In one case, a patient experienced acute hepatitis and jaundice when taking untreated lesser celandine extracts internally as an herbal remedy for hemorrhoids.
II. How to Grow and Care
Two key special care points include: its propensity to spread aggressively, requiring careful management to prevent it from overtaking other plants; and a dormant period after spring flowering, during which it can look unsightly as it dies back. Regular monitoring and control of its spread are the most important aspects of its care.
Sunlight and Soil
Lesser celandine tends to be quite hardy and low-maintenance, thriving in moist, well-drained soil and partial to full shade.
Watering
Thriving in moist environments, lesser celandine is naturally adapted to the damp conditions of its native woodland settings. This species exhibits a preference for consistent moisture, aligning with its habitat’s periodic rainfall patterns. It maintains a balance by tolerating brief dry spells but generally favors a well-hydrated state. Care should involve watering every week to mimic these natural conditions. As an herbaceous perennial, lesser celandine often grows outdoors where it can capitalize on the seasonal rains that promote its lush growth and springtime flowering.
Propagation
Lesser celandine predominantly propagates by sowing during the Spring season. It has a reputation for being relatively easy to propagate. Successful propagation is indicated by noticeable germination and budding. Ensure adequate moisture and warmth for optimal growth.
Transplanting
The optimal time for relocating lesser celandine is during the heart of spring, leveraging robust growth. Choose well-draining soil in dappled shade. For best results, ensure soil is moist and enriched with organic matter.
Repotting
When repotting lesser celandine, a low-growing ground cover, aim to do so every 2-3 years to maintain its vigor. Best repotted in early spring before the rapid growth phase, choose a shallow container matching its spreading habit. Use well-draining soil, and keep it moist for smooth acclimatization. Ensure the pot promotes drainage to prevent root rot, crucial post-repotting. These simple steps promise a thriving, cheerful lesser celandine.
III. Uses and Benefits
The plant is known as pilewort by some herbalists because it has historically been used to treat piles (hemorrhoids). Lesser celandine is still recommended in several “current” herbal guides for treatment of hemorrhoids by applying an ointment of raw leaves as a cream or lanolin to the affected area. Supposedly, the knobby tubers of the plant resemble piles, and according to the doctrine of signatures this resemblance suggests that pilewort could be used to cure piles.
Nicholas Culpepper (1616 – 1654), is claimed to have treated his daughter for ‘scrofula’ (or Kings evil) with the plant.
The German vernacular skorbutkraut (“scurvy herb”) derives from the use of young leaves, which are high in vitamin C, to prevent scurvy. However, use of lesser celandine to prevent scurvy could be considered a misnomer, tied to its similar appearance to common scurvygrass (Cochlearia officinalis), which shares similarly shaped leaves as well as sharing the german name skorbutkraut.
The German Hager’s Manual of pharmacy practice of 1900 states Ranunculus ficaria [sic] and C. officinalis both share this name and use, though there was little documentation of the toxicity of untreated Ficaria species at the time.
Most guides today point out that medicines should be made from the dried herb or by heat extraction as the untreated plants and extracts will contain protoanemonin, a mild toxin. The plant has been widely used in Russia and is sold in most pharmacies as a dried herb.
The protoanemonin found in fresh leaves is an irritant and mildly toxic but is suggested to have antibacterial properties if used externally. The process of heating or drying turns the Ranunculaceae toxin to anemonin which is non-toxic and may have antispasmodic and analgesic properties.
Mesolithic Hunter gatherers in Europe consumed the roots of the plant as a source of carbohydrates boiled, fried or roasted.
