Alder Buckthorn

Basic Information

Scientific Name: Frangula alnus

Plant Family: Rhamnaceae

Conservation / Invasive Status: Least Concern

Geographic Range: Europe, Introduced/Invasive

Safety Level: Use with Caution

Harvest Season: Fall, Late Summer

Parts Used: Bark

Scientific & Botanical Information

Botanical Description

Frangula alnus Mill. (syn. Rhamnus frangula L.) is a tall deciduous shrub in the family Rhamnaceae, reaching 3–7 metres in height and occasionally forming a small tree with a trunk diameter up to 20 cm.1 It is thornless — a key field distinction from its close relative Rhamnus cathartica (common buckthorn), which bears sharp spine-tipped branches.2 The bark is dark blackish-brown to purplish-grey on the exterior; when scratched or cut, the inner bark reveals a strikingly bright lemon-yellow to orange colour, a diagnostic character of the species used to confirm identification in the field.1

Leaves are alternate, simple, oval to obovate, with 7–9 pairs of prominent parallel lateral veins and smooth, untoothed margins — contrasting with the sub-opposite, 2–3-veined, finely toothed leaves of R. cathartica.2 The foliage has a characteristic glossy sheen, giving rise to the North American common name glossy buckthorn. Flowers are small, bisexual, greenish-white, borne in axillary clusters from May through August. The fruit is a drupe 6–10 mm in diameter, ripening through green to red to purple-black; multiple colour stages are often present simultaneously on one plant as birds consume and disperse the ripe fruits.1 Each drupe contains 2–3 seeds.

Geographic Distribution & Habitat

Frangula alnus is native across Europe, western and central Asia, and northernmost Africa — from Ireland and Britain eastward through central Europe to central Siberia and western China (Xinjiang), and from the 68th parallel in Scandinavia south to northern Morocco, Turkey, the Caucasus, and northern Iran.3 In its native range it occupies moist, often acidic, moderately fertile soils: fens, wet heathlands, boggy woodland margins, carr, and riparian shrublands — growing naturally alongside alders (Alnus spp.) and willows, which gave rise to the common name alder buckthorn. It has no native presence anywhere in North America.

F. alnus was introduced to North America approximately 200 years ago, planted for hedgerows, forestry shelter belts, and wildlife habitat programs.3 It has since naturalized extensively across the northeastern United States and southeastern Canada as an invasive shrub in moist woodlands, wetlands, forest edges, and disturbed areas from New England through the Great Lakes region and into the upper Midwest.4 In New England it is recognized as invasive across Vermont, New Hampshire, Massachusetts, Connecticut, and Rhode Island; its sale and transport are banned in Minnesota and Illinois.4

Ecologically, established invasive populations form dense, persistent, multi-stemmed thickets. F. alnus tolerates shade, enabling it to establish under closed forest canopy, and produces prolific bird-dispersed fruits. Studies in New Hampshire pine-hardwood forests document that buckthorn thickets significantly reduce native understory plant species richness and density, and suppress tree seedling recruitment — with tree seedling density inversely correlated with buckthorn basal area.4 Studies of arthropod communities in invaded forests document substantially lower insect abundance and caterpillar biomass on F. alnus relative to native vegetation, with cascading negative effects on insectivorous birds and higher trophic levels.5

Active Compounds

The bark of aged F. alnus contains 3–7% total hydroxyanthraquinone glycosides by dry weight, comprising the primary pharmacologically active fraction.1 Principal constituents include:

  • Glucofrangulin A and B: The dominant anthraquinone diglycosides in the bark; glucofrangulin A carries rhamnose at C-6 and glucose at C-8. These are the therapeutically active laxative compounds in properly aged bark.1
  • Frangulin A and B: Monoglycosides (rhamnose only) formed by partial hydrolysis of the glucofrangulins; frangulin A is emodin-6-O-rhamnoside.8
  • Emodin (frangula emodin): A free anthraquinone aglycone present at approximately 2.03 mg/g in the bark; the most extensively studied individual compound from F. alnus, with pharmacological activity well beyond laxation.6
  • Chrysophanol and aloe-emodin: Additional anthraquinone aglycones present in smaller concentrations.1
  • Anthrone glycosides (fresh bark only): In fresh bark, the anthraquinone fraction exists largely in its reduced anthrone form — principally frangulaemodin-anthrone. These compounds are responsible for the violently purgative and emetic toxicity of fresh bark. Oxidation during one year of drying converts anthrones to the therapeutic anthraquinone forms; this is a chemical transformation, not merely dilution.8

Beyond the anthraquinone fraction, bark and leaves contain flavonoids (quercetin, quercitrin, trifolin, rutoside, cymaroside), tannins, peptide alkaloids, and polyphenolic acids (chlorogenic acid, p-coumaric acid, rosmarinic acid, ferulic acid) identified in leaf extracts.7 The bark yields a yellow dye from its tannin fraction; unripe berries furnish the artist’s pigment sap green; ripe berries yield a blue-grey dye.1

Pharmacological Actions

The laxative mechanism of aged bark is well characterized. Anthraquinone glycosides pass through the upper gastrointestinal tract largely intact — minimally absorbed in the small intestine — and reach the colon, where bacterial enzymes hydrolyze them to active aglycones. These stimulate colonic peristalsis and inhibit electrolyte and water reabsorption from the colonic mucosa, producing laxation within 6–12 hours of ingestion.8 Compared to Rhamnus cathartica fruit preparations, which produce a faster-onset and more griping cathartic effect, F. alnus bark preparations are characterised as the milder, better-tolerated cathartic of the two species.14

Anticancer and cytotoxic activity has been demonstrated in vitro. Leaf extracts of F. alnus show cytotoxic effects against Jurkat (leukemia), MCF-7 (breast), HeLa (cervical), and HT-29 (colorectal) cancer cell lines, with activity mediated through activation of caspase enzymes (caspase 2, 6, 8, and 9) and induction of apoptosis.7 A 2023 study investigated bark extracts specifically against hepatocellular and colorectal carcinoma models in vitro, identifying the anthraquinone fraction as the primary cytotoxic agent.9

Antimicrobial activity is well documented. Ethyl-acetate bark extracts and isolated emodin demonstrate potent antistaphylococcal activity, including significant inhibition of bacterial biofilm formation, with MIC values at or below 2.5 mg/mL — an activity of relevance given the prevalence of drug-resistant staphylococcal strains.10 Studies of aqueous and ethanolic bark extracts confirm activity against both environmental and probiotic bacterial strains.11

Antioxidant activity is attributable to both the anthraquinone and polyphenolic fractions, with significant ROS scavenging capacity demonstrated in DPPH and FRAP assays; the polyphenols quercitrin and trifolin are identified as major contributors in leaf fractions.7

Frangulin A and B have been shown to inhibit multiple human carbonyl-reducing enzymes (including AKR1B10, CBR1, CBR3, and AKR1C1-3) at IC50 values in the low micromolar range (3.5–16.6 μM), suggesting potential pharmacokinetic interactions relevant in clinical and pharmaceutical contexts.12

Safety & Interactions

Fresh bark is toxic and must never be used internally. Anthrone glycosides in fresh bark cause violent purging, severe intestinal cramping, nausea, and vomiting. This is a qualitative toxicity, not merely a dose issue — the molecular form of the active compounds in fresh bark differs fundamentally from that in aged bark. Bark must be dried and aged for a minimum of 12 months, or heat-treated at 100°C for at least 2 hours, to allow oxidative conversion of anthrones to the therapeutic anthraquinone glycoside forms.8

Aged bark preparations are regulated as traditional herbal medicines in Europe under an EMA Community Herbal Monograph, which specifies a therapeutic adult dose of 20–30 mg total hydroxyanthracene derivatives (calculated as glucofrangulin A) per day for short-term occasional treatment of constipation, not exceeding one week of continuous use.8 The ESCOP monograph establishes the following contraindications: intestinal obstruction or ileus; inflammatory bowel disease (Crohn’s disease, ulcerative colitis); appendicitis or undiagnosed abdominal pain; children under 12 years; pregnancy and breastfeeding.13

Prolonged or excessive use risks electrolyte imbalance, particularly hypokalemia (potassium depletion), which may potentiate the effects of cardiac glycoside drugs and interact with antiarrhythmic agents.13 The berries are not used medicinally and should be considered toxic.

Growing in New England

Frangula alnus must not be planted or cultivated anywhere in New England or throughout northeastern North America. It is an established invasive with significant, well-documented ecological harm, listed as invasive by conservation authorities throughout the region. Cultivation risks further dispersal via bird-spread seeds into natural areas. All bark needed for medicinal or other purposes should be sourced from existing invasive populations, where harvesting biomass is a net ecological benefit.

For land stewards, F. alnus is a high-priority control target in moist woodlands, wetland margins, and forest edges throughout the region. It re-sprouts vigorously from cut stumps and should be treated with an appropriate cut-stump herbicide application, or subjected to repeated seasonal cutting to exhaust root reserves. Address populations before fruiting where possible to slow seed dispersal.5

Distinguishing Frangula alnus from Rhamnus cathartica

Both Frangula alnus and Rhamnus cathartica (common buckthorn, purging buckthorn) are invasive in New England, share the family Rhamnaceae, and have medicinal bark. They are distinct species with different compound profiles, and their preparations are not interchangeable. Key field distinctions:2

  • F. alnus: no thorns; alternate leaves; 7–9 pairs of parallel veins; smooth untoothed margins; yellow-orange inner bark; drupes with 2–3 seeds.
  • R. cathartica: thorny branch tips; opposite to sub-opposite leaves; 2–3 pairs of curved veins; finely toothed margins; yellow-orange inner bark (similar); drupes with 4 seeds.

Their anthraquinone profiles differ: F. alnus bark is characterised by glucofrangulins and frangulins, while R. cathartica bark and fruit are characterised by emodin, anthraquinone rhamnosides, and frangulin in different concentrations and ratios.14 Chloroplast genomic analysis confirms the phylogenetic distinctness of the two species within Rhamnaceae, resolving longstanding taxonomic confusion between them.2 Positive species identification is essential before harvesting bark from either species.

Pharmacological Actions: Anti-inflammatory, Antimicrobial, Antioxidant, Antispasmodic, Cathartic, Hepatoprotective, Laxative

Traditional Herbalism Information

Energetics & Actions

In European herbal tradition, Frangula alnus bark is classified as bitter in taste and energetically cooling and downward-moving, acting upon the large intestine to restore peristaltic function and clear accumulation.15 Its primary herbal actions are cathartic and stimulant laxative, with secondary actions as a mild cholagogue (promoting bile secretion and flow) and gentle hepatic tonic.15 Among the classic anthraquinone cathartics — senna, cascara sagrada, aloe, and rhubarb root — alder buckthorn is considered one of the gentler and more predictable, appropriate where reliable but non-violent cathartic action is indicated.

Parts Used & Their Applications

The bark — specifically the inner cortex of branches and stems of two or more years of age — is the sole part used in herbal medicine. It must be harvested, dried, and aged for a minimum of 12 months before any medicinal preparation. This is not a precaution based on potency alone: fresh bark contains anthrone glycosides that are qualitatively different molecules from the therapeutic anthraquinone glycosides that form during aging. The bright yellow-orange inner bark is a useful confirmation of species identity at harvest.15

The berries, while historically employed as a drastic purgative and as a dye source, are not used in contemporary herbal practice. Their anthraquinone content is less predictable than bark and the risk of adverse reaction is significant. Leaves have attracted recent scientific attention for their polyphenol content but have no established herbal tradition for internal use and should not be prepared as such.

Traditional Uses

Alder buckthorn bark has been used in European herbal medicine as a reliable cathartic since at least the Middle Ages, appearing in apothecary records and physician formularies across Britain, Germany, France, and central Europe.16 Grieve’s A Modern Herbal (1931) documents its widespread use in British domestic practice: the bark was boiled in ale as a traditional country remedy for jaundice; the syrup of buckthorn berries was prepared in many households as a domestic laxative through much of the 18th century; and the plant was regularly prescribed for sluggish intestinal function and haemorrhoids.17

The primary indication across all traditions is atonic constipation — sluggish bowel with reduced peristaltic tone — and constipation where straining must be avoided, particularly in the presence of haemorrhoids or anal fissures. Secondary traditional uses include liver and gallbladder congestion, based on the plant’s mild cholagogue action, and bilious complaints — the cluster of symptoms associated with impaired bile flow: nausea, right-sided discomfort, and sluggishness after fatty meals.16 The bark was listed in numerous European pharmacopoeias through the 19th and 20th centuries, and Frangulae cortex remains pharmacopoeially recognised under the European Pharmacopoeia today.

Preparations & Dosage

Decoction: 1–2 teaspoons of properly aged, dried, chopped bark (approximately 2–4 g) per cup of water. Bring to a gentle simmer, cover, and maintain for 15 minutes. Strain and take one cup in the evening. Expect effects within 6–12 hours.18

Tincture: 1:5 in 40–45% ethanol, prepared only from properly aged dried bark. Dose: 2–4 mL at bedtime in a small amount of water. Not to exceed one to two weeks of continuous use.18

Standardised extract: The EMA Community Herbal Monograph specifies 20–30 mg total hydroxyanthracene derivatives (calculated as glucofrangulin A) as the adult daily dose in pharmaceutical preparations — a standard met by licensed European herbal products.8

All preparations are for short-term occasional use only. Chronic use of stimulant laxatives risks laxative dependency, reduced intrinsic bowel motility, and electrolyte depletion. Dietary fibre and adequate hydration should be addressed as first-line interventions for chronic constipation.

Modern Adaptations

Frangula alnus bark remains a regulated traditional herbal medicine in European commerce, appearing in licensed products for occasional constipation. It is less common in North American herbal practice than cascara sagrada (Frangula purshiana, formerly Rhamnus purshiana), a Pacific Northwest native with a closely analogous anthraquinone profile that has been the standard anthraquinone cathartic in Western North American herbalism. For Northeast practitioners, F. alnus bark sourced from invasive populations represents a locally available and ecologically sound alternative, provided positive species identification is established and the 12-month aging requirement is observed.18

Contemporary clinical herbalists generally follow EMA and ESCOP guidance for this plant: short-term use only, in combination with dietary support, and with contraindications strictly observed. The plant appears more commonly in compound formulations alongside bitters, carminatives, and hepatics than as a standalone preparation.

New England Specific

For New England-based herbalists and foragers, F. alnus presents a clear ethical position: wildcraft freely, do not cultivate. The plant is invasive and ecologically harmful throughout the region, yet abundantly established in disturbed moist habitats — roadsides, wetland margins, forest edges, and cut-over woodlands across Vermont, New Hampshire, Massachusetts, Connecticut, and Rhode Island. Removing bark from these populations is a direct contribution to ecological restoration.

Bark is best harvested in late summer to early autumn, when the plant is in active growth and the bark separates cleanly. Take branches of 2–4 cm diameter from multi-stemmed plants using loppers or a folding saw; score the bark longitudinally and peel strips of the inner bark. Spread in a single layer on screens in a warm, ventilated space, turning regularly, and dry for a full 12 months before any internal preparation. Label clearly with species, harvest location, and harvest date. Do not compost fruiting branches — bag and dispose as general waste to prevent seed dispersal from the compost site.

Sourcing & Ethics

The ethical calculus for F. alnus is the inverse of standard wildcrafting guidance. Where most wildcrafting practice prioritizes conservation and prefers cultivated sources, for this plant: wildcrafting from established invasive populations is the ecologically responsible choice, and cultivation is actively discouraged. Purchasing or planting nursery-grown F. alnus risks introducing further plants into landscapes from which they can escape and establish. Do not cultivate this species.

For those purchasing commercially prepared bark, European suppliers are appropriate — where the plant is native and may be sustainably managed. Verify species identity: in North American commerce, “buckthorn bark” more commonly refers to cascara sagrada (F. purshiana), which has a different regulatory history. Ask suppliers to confirm the species as Frangula alnus or Rhamnus frangula.

Folk Wisdom

Country tradition in Britain held that the bark of the Black Dogwood boiled in ale was the surest remedy for jaundice — a belief that may reflect the plant’s genuine cholagogue action, however imprecisely understood. The name “Breaking Buckthorn” appears in some English regional traditions, referring either to the brittle quality of the wood or, in folk humour, to the plant’s decisive effect on the bowels. In rural European tradition, the yellow of the inner bark was sometimes taken as a sign of the plant’s affinity for liver complaints, following the doctrine of signatures.

Traditional Uses: Astringent, Digestive Support, Liver Support

Magical Correspondences Information

Planetary Ruler & Elemental Association

Buckthorn species are assigned to Saturn as planetary ruler, the Water element as governing element, and a Feminine polarity in Scott Cunningham’s Encyclopedia of Magical Herbs — the foundational English-language reference for herbal magical correspondences.19 This Saturnine attribution resonates across multiple registers: Saturn governs boundaries, law, binding, the dissolution of obstacles, and the clearing of what has become stagnant or entrenched — all qualities embodied by a plant whose primary action, medicinally and magically, is the forceful removal of what does not belong. The Water element aligns with F. alnus‘s native habitat in fens, bogs, and waterside margins, and with the fluid dynamics of its physiological action.19

An important note on species specificity: Cunningham’s entry covers Rhamnus spp. as a genus, without distinguishing between Frangula alnus (alder buckthorn) and Rhamnus cathartica (common buckthorn). This reflects a historical pattern in the magical literature: both species share common names and folk uses, and their magical attributions were not differentiated in practice. Beyerl’s The Master Book of Herbalism similarly addresses buckthorn family plants as a group.20 Practitioners working specifically with F. alnus should understand that the correspondences documented here are well supported as genus-level attributions, applied to F. alnus by reasonable extension — not as direct citations addressing this species alone. The current primary magical literature does not separately document Frangula alnus apart from the genus.

Magical Intentions & Uses

Cunningham documents four primary magical uses for buckthorn, all of which translate naturally to work with F. alnus bark:19

  • Protection: Bark or branches placed near doors and windows to ward off negative influences and banish unwanted energies from living spaces and persons.
  • Exorcism: Used in cleansing and banishing rites to expel harmful entities, accumulated negative energy, or spiritual obstruction from a person, home, or ritual space — a use that maps directly onto the plant’s medicinal action of clearing what does not belong from the body.
  • Legal matters: Carried or worn during court proceedings, or included in petition sachets seeking favourable legal outcomes. Cunningham specifically documents this as a practical folk magic application for the genus.19
  • Wishes: Used as a vehicle for wish magic and manifestation; the plant’s quality of compelling action and release makes it a traditional ally for intentions that have stalled or require a decisive push toward fruition.

Deity Associations

No specific deity associations for Frangula alnus appear in the primary magical texts reviewed. Within Saturnine tradition, Saturn-attributed plants fall under the dominion of Kronos/Saturn in Greco-Roman cosmology — the titan of time, necessity, and inevitable endings — and by extension figures associated with winter’s stripping power and the ruthless but necessary dissolution that makes room for renewal. F. alnus‘s liminal native habitat — at the edges of bogs, fens, and water margins — places it within the domain of threshold guardians and underworld figures in various European folk traditions.17 These associations derive from the plant’s ecological character and planetary attribution rather than from documented primary deity-specific traditions, and should be understood as reasoned inference.

Ritual & Spellwork Applications

In practical spellwork, buckthorn bark is burned as incense, carried in sachets, or used to mark thresholds. Beyerl documents the protective tradition of placing buckthorn at doors and windows — aligning with the broader European hedge-magic tradition of planting or hanging bitter-barked plants at household boundaries to prevent the passage of harmful forces.20 Though F. alnus is thornless (unlike the thorny R. cathartica), the Saturnine protective quality is attributed to the genus, not the thorns themselves.

For legal matters: add the bark to a brown or black cloth sachet alongside other Saturnine herbs — comfrey root, mullein, or black cohosh — and carry discreetly during proceedings, or place beneath a candle burned on Saturday. For banishing: burn a small amount of dried bark on a charcoal disk during a waning moon, with spoken intention of what is to be expelled. For wish work: burn bark with a written petition, with the intent that the plant’s compelling force carries the wish toward manifestation.19

Traditional Lore & Folk Magic

Beyerl’s The Master Book of Herbalism places buckthorn within a broader European apotropaic tradition, noting its use in protective and purificatory contexts across several folk magic systems.20 A fragment of folk belief recorded in plant lore compilations holds that sprinkling buckthorn in a circle and dancing within it during a full moon may summon a spirit — sometimes described as an elf or fairy — who will grant a wish.21 This belief connects the plant to liminal spaces, the full moon’s transformative power, and the boundary between ordinary and magical worlds. The precise origin of this belief is uncertain; it appears in multiple folk lore compilations but lacks a clear primary oral or textual source and is included here for completeness.

Grieve’s A Modern Herbal (1931) documents the English country practice of hanging Black Dogwood above the door to keep the house free of malice, recording the plant’s apotropaic folk reputation in the same volume that describes its medicinal uses.17 Because documented magical lore specific to Frangula alnus is sparse — the primary magical literature addresses Rhamnus spp. as a genus — practitioners should approach any species-specific magical claims for this plant with appropriate critical assessment.

Timing

Given the Saturnine correspondence, buckthorn magic is traditionally aligned with Saturday (Saturn’s day) and with planetary hours of Saturn in classical timing systems.19 The waning moon is the appropriate phase for banishing, exorcism, and clearing work. The waxing moon suits protective workings intended to build a shield, and wish work directed toward manifestation. As a Water-element plant, working near still or slow-moving water — fens, bog margins, the edges of ponds — creates resonance between the working and the plant’s inherent nature. Late summer and early autumn, when the bark is most medicinally potent, is a natural season for harvesting magical material as well.

Working with Alder Buckthorn in Practice

The bark is the most practical and energetically appropriate part to work with. To prepare for magical use: harvest from positively identified invasive populations (the diagnostic bright yellow inner bark is a useful confirmation of identity), dry in thin strips in good ventilation, and store in paper or cloth rather than sealed plastic. Label with harvest date, location, and species.

In New England, wildcrafting F. alnus bark for magical purposes is an act with genuine ecological meaning: removing biomass from an invasive population that displaces native plants is itself a protective working for the land. This alignment between practical ecological action and magical intention gives work with this plant a particular integrity for practitioners operating at the intersection of earth stewardship and magical practice.

The bark’s scent when burned is resinous, bitter, and astringent — appropriate to Saturnine and banishing work where sweetness would be energetically incongruous. It can be combined with frankincense or copal resin on a charcoal disk to make it more workable in enclosed ritual spaces.

Combining with Other Plants

For protection: pairs well with rowan berries, hawthorn wood, nettle, and mugwort — plants with well-established European protective reputations that reinforce the Saturnine quality of buckthorn without diffusing it. For legal matters: combine with High John the Conqueror root, calendula, and bay laurel (bearing a written petition). For banishing and exorcism: pair with rue, angelica root, and frankincense. For wish magic: combine with vervain and bay laurel to anchor the petition, and cinnamon to add fire and momentum to the intention.19

Cautions for Magical Use

Do not burn large quantities of buckthorn bark in enclosed spaces — as with all anthraquinone-containing plant materials, smoke may carry irritant compounds. Use small amounts in well-ventilated ritual environments. Wash hands after handling the bark. Do not ingest bark that has not been properly aged for at least 12 months for any purpose — this caution applies equally to magical preparations that include plant material taken internally. Approach this plant as a working ally with genuine force: banishing work done without clear and specific intention may clear more than intended.

Folk Wisdom

It was said in English country tradition that a branch of the Black Dogwood hung above the threshold would keep the house free of malice — whether from ill-wishing, bad luck, or the evil eye. The plant’s reputation for force — what needed to leave, would leave — made it a natural emblem of inevitable clearing, of the moment when accumulated stagnation can no longer be held back. This quality of necessary release is perhaps the most enduring thread connecting the plant’s physical and magical identities across traditions.17

Planetary Rulers: Saturn

Magical Intentions: Banishing, exorcism, Legal Success, Protection, Wishes

Elemental Associations: Water

  1. Olszewska, M.A., Nowak, S., Olszewski, J., Mencel, K., and Nowak, R. (2012). Anthraquinone profiles, antioxidant and antimicrobial properties of Frangula rupestris (Scop.) Schur and Frangula alnus Mill. bark. Food Chemistry, 131(3), 765-772.
  2. Shafiq, M., et al. (2023). Uncovering the first complete chloroplast genomics, comparative analysis, and phylogenetic relationships of the medicinal plants Rhamnus cathartica and Frangula alnus (Rhamnaceae). Physiology and Molecular Biology of Plants, 29, 947-960.
  3. Dlugosch, K.M., et al. (2016). Transatlantic invasion routes and adaptive potential in North American populations of the invasive glossy buckthorn, Frangula alnus. Ecology and Evolution, 6(22), 8098-8111.
  4. Foster, D.R., et al. (2020). Factors limiting the success of invasive glossy buckthorn (Frangula alnus) in New Hampshire eastern white pine-hardwood forests. Forest Ecology and Management, 480, 118657.
  5. Grevstad, F.S., et al. (2023). Arthropods Associated with Invasive Frangula alnus (Rosales: Rhamnaceae): Implications for Invasive Plant and Insect Management. Insects, 14(12), 913.
  6. Zdravkovic, A.S., et al. (2015). Toxicity and antioxidant capacity of Frangula alnus Mill. bark and its active component emodin. Industrial Crops and Products, 73, 386-392.
  7. Nazaruk, J., et al. (2020). Polyphenols of Frangula alnus and Peganum harmala Leaves and Associated Biological Activities. Plants, 9(9), 1086.
  8. European Medicines Agency. (2016). European Union herbal monograph on Rhamnus frangula L., cortex, revision 1. EMA/HMPC/137507/2005 Rev. 1.
  9. Sokolik, R., et al. (2023). Could alder buckthorn (Frangula alnus Mill) be a source of chemotherapeutics effective against hepato- and colorectal carcinoma? An in vitro study. PMID 37973300.
  10. Aleksic, V., et al. (2020). Antistaphylococcal and biofilm inhibitory activities of Frangula alnus bark ethyl-acetate extract. Industrial Crops and Products, 155, 112840.
  11. Wierzbicki, M., et al. (2022). Extracts from Frangula alnus Mill. and Their Effects on Environmental and Probiotic Bacteria. International Journal of Molecular Sciences, 23(19), 11894.
  12. Hintzpeter, J., et al. (2022). Inhibition of human carbonyl reducing enzymes by plant anthrone and anthraquinone derivatives. Biochemical Pharmacology, 199, 115014.
  13. ESCOP. (2003). Frangulae cortex (Frangula Bark). In: ESCOP Monographs, 2nd edition. European Scientific Cooperative on Phytotherapy, Thieme.
  14. Tanczos, B., et al. (2015). Comparison of laxative effect of preparations from Frangula alnus bark and Rhamnus cathartica fruits (Rhamnaceae). Herba Polonica, 61(1), 34-44.
  15. Hoffmann, D. (2003). Medical Herbalism: The Science and Practice of Herbal Medicine. Healing Arts Press, Rochester, VT.
  16. Tilgner, S. (1999). Herbal Medicine from the Heart of the Earth. Wise Acres Press, Creswell, OR.
  17. Grieve, M. (1931). A Modern Herbal (Buckthorns entry). Jonathan Cape, London. Reprinted 1971, Dover Publications.
  18. Felter, H.W. and Lloyd, J.U. (1898). King’s American Dispensatory, 18th edition. Ohio Valley Company, Cincinnati.
  19. Cunningham, S. (1985). Cunningham’s Encyclopedia of Magical Herbs. Llewellyn Publications, St. Paul, MN.
  20. Beyerl, P. (1984). The Master Book of Herbalism. Phoenix Publishing, Custer, WA.
  21. Thiselton-Dyer, T.F. (1889). The Folk-Lore of Plants. Appleton, New York.