Calendula is a genus of about 25 species of annual and perennial herbaceous plants in the daisy family, Asteraceae that are often known as marigolds. They are native to Europe, North Africa, Macaronesia and West Asia, and have their center of diversity in the Mediterranean Region.
Typically bright yellow to deep orange, sometimes with two-toned petals. The flowers are daisy-like with a central disc surrounded by ray florets. They can be single or double, depending on the cultivar. Lanceolate to ovate, often with a slightly hairy or sticky texture due to glandular trichomes. They are arranged alternately on the stem. Erect, branching, and can be hairy. The plants grow up to 30-60 cm in height, depending on the variety and growing conditions.
The plant has a bushy growth, which can be quite robust in fertile soil. Blooms profusely from late spring through the first frosts in autumn, making it a long-season flower. The flowers have a distinctive, somewhat musky or medicinal scent, which can be quite strong, especially in certain cultivars.
Easily grown from seeds, which can be directly sown in the garden or started indoors for earlier blooms. Self-seeds freely if not deadheaded, contributing to its presence in wilder or cottage garden settings. While calendula is an annual in temperate climates, it can sometimes overwinter in warmer zones or in protected locations, acting as a short-lived perennial.
Calendula Varieties
Calendula officinalis
This is the most common type of calendula, often simply referred to as pot marigold. It’s widely used for its medicinal properties, particularly in skin care due to its anti-inflammatory and healing effects.
Calendula arvensis
Known as field marigold, this species is less common in gardens but can be found in wilder settings. It has smaller flowers compared to C. officinalis and is not as extensively used for medicinal purposes.
Calendula arvensis var. arvensis
A variety of the field marigold, it’s distinguished by its slightly different leaf shape or flower size, often specific to certain geographic regions.
Calendula suffruticosa
Also known as Sicilian marigold, this variety is a perennial from the Mediterranean region. It has woody stems and can grow up to 50 cm tall, with flowers that are less double than those of C. officinalis.
Calendula stellata
This type features star-shaped flowers, hence the name “stellata.” It’s less known in cultivation but interesting for its unique flower structure.
Calendula alata
This species has winged stems, which is where it gets its name ‘alata’ (winged). It’s not commonly found in gardens but can be part of botanical collections.
Calendula maderensis
Native to Madeira, this calendula is adapted to grow in rocky, somewhat arid conditions. It has distinctive, often solitary, large flowers.
Calendula fulgida
This species is known for its bright, shining (fulgida means shining) yellow-orange flowers, which are solitary and larger than those of many other species.
Calendula denticulata
With finely toothed leaves (hence ‘denticulata’), this species is less common but appreciated for its ornamental value. It’s not typically used for medicinal purposes.
Calendula eckerleinii
A rare species named after Eckerlein, an Austrian botanist. It’s not widely grown but can be found in specialized plant collections, often noted for its habitat in the Balkan Peninsula.
Calendula tripterocarpa
This species features flowers with three-winged fruits, which is reflected in its name. It’s less common in cultivation but interesting for botanical studies.
Calendula pachysperma
This type has thick-seeded fruits. It’s adapted to harsh environments, often found in the eastern Mediterranean.
Calendula incana
Known for its woolly or hairy leaves, this calendula adds texture to any garden. It’s not commonly used for medicinal purposes but is still ornamental.
Calendula maroccana
Native to Morocco, this variety has been selectively bred for garden use, offering vibrant colors and larger flowers than some wild types.
Calendula palaestina
Found in Palestine, this species might be of interest for those studying regional flora, with adaptations for the local climate and soil conditions.
Calendula persica
A species from Iran, it’s not widely known outside of botanical circles. It has a distinct growth habit, often with a more sprawling nature.
Calendula suffruticosa var. lusitanica
A variant of the Sicilian marigold, this one is from Portugal, showing regional variation in a species already noted for its variability.
Calendula stellata var. integrifolia
A variety of the star marigold with entire, not toothed, leaves. This variation might have different ecological preferences.
Calendula bicolor
While not officially recognized by some taxonomic classifications, this term might refer to varieties or cultivars of calendula with two-toned flowers, often a result of selective breeding.
Calendula officinalis ‘Lemon Cream’
Although technically a cultivar of the common calendula, it’s worth mentioning for its unique lemon-yellow flowers, showcasing how breeding can lead to new types with distinct appearances.
Calendula suffruticosa var. aurantiaca
This variety of the Sicilian marigold has vibrant orange flowers. It’s notable for its slightly different flower color compared to the typical yellow-orange of many calendulas.
Calendula suffruticosa var. tomentosa
Another variant of the Sicilian marigold, this one is characterized by its tomentose (densely hairy) leaves, giving it a distinctive texture.
Calendula incana var. microcephala
A variation of the woolly calendula with smaller flower heads. This type might be adapted to specific microclimates or ecological niches.
Calendula officinalis ‘Kablouna’
A cultivar of the common pot marigold known for its large, fully double flowers. It’s bred for ornamental purposes, showcasing the breadth of variation that can be achieved through selective breeding within the species.