Nasturtium Botany, Ethnobotany, and Phytochemistry: Scientific Guide

Nasturtium Botany and Phytochemistry

Tropaeolum majus represents a fascinating intersection of ornamental horticulture, culinary use, and phytomedicine. Its rich ethnobotanical history and complex phytochemistry make it a subject of increasing scientific interest for its antimicrobial, anti-cancer, and nutritional properties.

Taxonomy and Evolutionary Biology

Classification

Rank	Classification
Kingdom	Plantae
Order	Brassicales
Family	Tropaeolaceae
Genus	Tropaeolum L.
Species	T. majus L.
Common names	Garden nasturtium, Indian cress

Family Characteristics

Feature	Details
Family size	~90 species in 1 genus
Distribution	South and Central America
Age	~100 million years
Relationship	Sister to Brassicaceae (mustard family)
Unique feature	Fleshy vines with twining petioles

Species in Cultivation

Species	Features
T. majus	Common garden nasturtium
T. minus	Smaller, more compact
T. peregrinum	Canary creeper, yellow fringed flowers
T. tuberosum	Edible tubers (Mashua)
T. speciosum	Flame nasturtium, perennial

Genetics

Chromosomal Information

Feature	Value
Chromosome number	2n = 28
Base number	x = 14 (likely)
Ploidy	Evidence of tetraploidy
Genome	Recently sequenced

Genomic Resources

Resource	Status
Genome assembly	Available
Chloroplast genome	Sequenced
Transcriptome	RNA-Seq data available
Focus	Flavonoid biosynthesis genes

Plant Morphology

Vegetative Structures

Stems:

Feature	Details
Habit	Trailing or climbing
Texture	Succulent, glabrous
Length	0.5-2+ meters
Climbing	Via twining petioles

Leaves:

Feature	Details
Shape	Peltate (umbrella-like)
Size	3-15 cm diameter
Color	Green to blue-green
Margin	Entire, wavy
Veins	Radiate from petiole

Reproductive Structures

Flowers:

Feature	Details
Size	2.5-6 cm diameter
Symmetry	Zygomorphic
Spur	2.5-3 cm, nectar-producing
Petals	5, upper 2 different
Stamens	8
Color	Yellow, orange, red spectrum

Fruit and Seeds:

Feature	Details
Fruit type	Schizocarp
Mericarps	3
Seed coat	Thick, wrinkled
Seed size	7-10 mm

Phytochemistry

Major Compound Classes

Class	Significance
Glucosinolates	Peppery flavor, antimicrobial
Flavonoids	Antioxidant, anti-inflammatory
Carotenoids	Pigments, nutrition
Anthocyanins	Red/purple pigments
Ascorbic acid	Vitamin C

Glucosinolates

Compound	Significance
Glucotropaeolin	Primary glucosinolate
Benzyl isothiocyanate	Hydrolysis product
Concentration	Highest in seeds
Function	Defense, antimicrobial

Antimicrobial Activity:

Target	Effectiveness
Bacteria	Broad spectrum
Fungi	Moderate
Viruses	Some activity
Mode	Cell membrane disruption

Flavonoids

Compounds	Notes
Quercetin glycosides	Primary flavonols
Kaempferol glycosides	Secondary flavonols
Anthocyanins	Flower pigments

Carotenoids

Compound	Significance
Lutein	Highest of any edible plant
Zeaxanthin	Eye health
β-carotene	Provitamin A
Concentration	45 mg/100g lutein

Nutritional Composition

Nutrient	Leaves	Flowers
Vitamin C	Very high	High
Iron	Significant	Present
Manganese	Good source	Present
Protein	3-4%	Lower
Calories	Low	Very low

Ethnobotany

Indigenous Use (Inca)

Application	Method
Food	Leaves and flowers in salads
Medicine	Tea for respiratory infections
Wound care	Poultice for cuts and burns
Preservation	Seeds preserved in salt

European Introduction (1500s)

Timeline	Development
~1500	Spanish conquistadors bring to Europe
1565	Documented by Nicolás Monardes
1597	Reached England (John Gerard)
1600s	Spread through European gardens
1774	Thomas Jefferson plants at Monticello

Traditional Medicinal Uses

System	Applications
Respiratory	Bronchitis, coughs, colds
Urinary	Urinary tract infections
Topical	Wounds, fungal infections
General	Antibiotic, antiseptic

Historical Names

Name	Origin
Indian cress	European settlers
Nasturtium	Latin "nose-twister"
Capuchine	French (flower shape)
Monks cress	Religious reference

Modern Research

Antimicrobial Studies

Finding	Significance
Benzyl isothiocyanate active	Confirms traditional use
Gram-positive bacteria	Strong activity
Gram-negative bacteria	Moderate activity
Fungi	Some activity
Potential	Alternative to antibiotics

Cancer Research

Finding	Notes
Isothiocyanates	Antiproliferative activity
Mechanism	Apoptosis induction
Status	Preliminary studies
Relationship	Similar to broccoli compounds

Lutein and Eye Health

Research	Findings
Bioavailability	Good from nasturtium
Concentration	Exceptional (45 mg/100g)
Function	Macular protection
Comparison	Higher than spinach, kale

Anti-inflammatory Effects

Compound	Activity
Flavonoids	COX inhibition
Isothiocyanates	NF-κB modulation
Potential	Inflammatory conditions

Commercial Applications

Ornamental Industry

Use	Market
Bedding plants	Home gardens
Seeds	Direct-sow market
Trailing types	Hanging baskets
Edible landscaping	Growing segment

Culinary Market

Product	Application
Fresh flowers	Restaurant garnish
Leaves	Specialty greens
Pickled seeds	Gourmet condiment
Flower extracts	Natural coloring

Phytomedicine

Product	Status
Herbal preparations	Traditional use
Standardized extracts	Research stage
Combination products	With horseradish
UTI prevention	Commercial products in Europe

Cultivation Science

Environmental Requirements

Factor	Optimal Range
Temperature	50-75°F (10-24°C)
Light	Full sun to part shade
Soil pH	6.0-7.5
Fertility	Low to moderate

Stress Responses

Stress	Response
Heat	Reduced flowering
Nitrogen excess	Vegetative over floral
Water stress	Tolerated once established
Frost	Fatal

Seed Biology

Feature	Details
Germination	7-14 days
Temperature	55-65°F optimal
Dormancy	None significant
Light	Not required
Viability	5+ years

Research Directions

Current Focus Areas

Area	Status
Genome annotation	Ongoing
Flavonoid biosynthesis	Active research
Antimicrobial mechanisms	Continuing
Lutein bioavailability	Clinical studies

Potential Applications

Area	Potential
Natural preservatives	Antimicrobial compounds
Nutraceuticals	Lutein, isothiocyanates
Biopesticides	Glucosinolate-based
Functional foods	Enhanced nutrition

Breeding Goals

Target	Approach
Higher glucosinolates	Selection
Enhanced lutein	Genetic analysis
Compact habit	Continued improvement
Disease resistance	Screening programs

Conservation Status

Factor	Status
Wild populations	Secure in Andes
Genetic diversity	Maintained in cultivation
Seed banks	Preserved
Concerns	None major

The intersection of traditional knowledge and modern science continues to reveal the remarkable properties of Tropaeolum majus, validating centuries of empirical use while opening new avenues for research and application.