Plant Monograph: American Cranesbill

Name of plant:
American cranesbill

Catch phrase (Carmina Gadelica or traditional invocation if available):
No Carmina Gadelica attribution exists (non-native to Celtic tradition).
In European folk herbalism it was often referred to as:
“The root that binds the flow and steadies the waters of the body.”

Family:
Geraniaceae

Genus and species:
Geranium maculatum

Other names:
Wild geranium, Spotted geranium, Alum root (shared folk name), Cranesbill geranium

Brief introduction:
American cranesbill is a perennial woodland herb native to eastern North America. It is recognized by its deeply lobed leaves and delicate pink-purple flowers. The plant is most valued medicinally for its astringent root, which has been widely used in traditional North American herbalism for gastrointestinal and mucosal support.

Traditional uses:

• Diarrhea and gastrointestinal irritation (astringent remedy)

• Mouth and throat rinses for inflammation

• Topical washes for minor wounds and skin irritation

• Hemorrhoidal support in traditional herbal practice

• General mucosal toning in folk herbal systems

Historical use:

• Used by Indigenous North American peoples for digestive and wound care

• Adopted into 19th-century Eclectic and Physiomedical herbalism

• Frequently included in North American materia medica as a reliable astringent root

• Used in household herbal medicine as a substitute for imported astringents like imported tannin-rich barks

• Continued use in Western herbalism into the present as a mild, safe astringent

Parts used and method of use:

• Root (primary medicinal part)

• Occasionally aerial parts, but much weaker in effect
  Used as:

• Decoction (root tea)

• Tincture

• Powdered root in capsules (modern herbal practice)

• Topical wash or compress

Use in healing (modern herbal practice):

• Strong astringent for gastrointestinal irritation and mild diarrhea

• Mucosal toning herb for mouth, throat, and gut lining

• Topical support for minor wounds and skin irritation

• Hemorrhoidal comfort applications (traditional use)

• Considered a reliable but gentle tannin-based herb in Western herbalism

Pharmacology and biochemistry:

• High levels of tannins (gallotannins and related polyphenols)

• Contains flavonoids and phenolic acids

• Mechanism:

  • Protein precipitation → reduced secretions and tissue tightening

  • Mild antimicrobial activity via tannin action

• Observed effects:

  • Astringent action on mucous membranes

  • Reduction of intestinal fluid secretion (supporting anti-diarrheal use)

  • Mild anti-inflammatory activity in topical use

Common dosage:

• Decoction: 1–2 teaspoons dried root per cup, simmered 10–15 minutes, up to 2–3 times daily

• Tincture (1:5 or similar): 2–4 mL up to 3 times daily in traditional herbal practice

• Powdered root: 0.5–2 g per dose (less commonly used internally today)

Safety factors (including side effects):

• Generally safe in traditional doses

• High tannin content may cause constipation if overused

• May irritate stomach in sensitive individuals if taken in excess

• Not recommended for long-term continuous use without breaks

• Very low toxicity profile compared to stronger astringents

First aid / adverse reaction response:

• Constipation: reduce dose or discontinue use

• GI irritation: stop use and hydrate

• Rare allergic reaction: discontinue and seek medical advice if severe

• No known acute toxicity at traditional dosing levels

Drug interactions:

• May reduce absorption of oral medications if taken simultaneously (tannin binding) → separate dosing by 1–2 hours

• No well-documented clinically significant drug interactions

• Caution with iron supplements if taken at same time (reduced absorption possible)

Horticultural requirements:

• USDA / Canadian zone: 3–8

• Soil pH: 5.5–7.0 (prefers slightly acidic woodland soils)

• Light requirements: Partial shade to full shade

• Moisture: Moderate; prefers moist, well-drained woodland soils

• Other notes (growth habit, harvest timing, etc.):

  • Woodland perennial, 30–60 cm tall

  • Flowers in late spring to early summer

  • Roots harvested in autumn of second year or later for highest potency

  • Spreads slowly in suitable forest-floor conditions

  • Often found in deciduous forest understories

Sampling of clinical reports / studies:

• Phytochemical studies confirm high tannin content as primary active constituent

• In vitro research shows mild antimicrobial and antioxidant activity from polyphenolic compounds

• Historical Eclectic medicine literature consistently documents use as a dependable anti-diarrheal and mucosal astringent

• Limited modern clinical trials exist; most evidence is based on traditional use and phytochemical inference

• Contemporary herbal consensus classifies it as a safe, moderate-strength astringent herb for gastrointestinal and mucosal support