About Centella cordifolia (Hook.fil.) Nannf.
Taxonomic Identity
Centella cordifolia (Hook.fil.) Nannf. is a groundcover herb that reaches up to 15 cm (5.9 in) in height and typically spreads 1–2 m (3 ft 3 in – 6 ft 7 in) wide.
Leaf Morphology
Its leaves are heart-shaped (cordate), glabrescent, glossy, and dark green. The leaf blade (lamina) measures 1–3 cm (0.39–1.18 in) in length, with a roughly equal width, has five to seven veins and scarious margins.
Light Response
Leaf position changes with light: leaves lie low to the ground in direct sun, and stand upright in shade.
Petiole Characteristics
The petiole has a purple tint, is sheathing and broad at the base, and can grow up to five times the length of the leaf blade.
Inflorescence Structure
Flowers grow in ovate, subsessile umbels that are 3 mm (0.12 in) long, with each umbel holding two to three florets. Petals are purple or white, ovate, and around 1.5 mm (0.059 in) long.
Flower Parts
Sepals form a very small, lobed ring, with two involucral bracts at the base. Anthers are dark purple.
Flowering Period
Centella cordifolia flowers from late summer (December) to early autumn (March).
Fruit Characteristics
Its fruit is small, rounded, laterally compressed, and contains seeds. The mericarp has five longitudinal ribs, measures 2.5–3 mm (0.098–0.118 in) long and 4–5 mm (0.16–0.20 in) wide, and is generally glabrous, though small hairs may be present near its apex.
Species Distinction
Distinguishing Centella cordifolia from other Centella species can be difficult, especially from C. asiatica, which also grows in parts of Australia. Centella cordifolia has more serrate leaf margins, while C. asiatica has more dentate margins.
Growth Habit
It also has a mat-like growth habit, which sets it apart from other Centella species with more vertically extensive spreading growth habits.
Native Range
Centella cordifolia is native to Australia, where it occurs in parts of Western Australia, South Australia, New South Wales, Victoria and Tasmania. The species has limited recorded occurrences, and its full distribution is not well understood.
Habitat
It grows in damp, poorly drained environments, including marshy soils or shallow water, and tolerates growing conditions from full sun to partial shade.
Environmental Tolerances
It is intolerant of phosphorus and moderately tolerant of frost.
Medicinal Use
Centella cordifolia has been used to treat rheumatism and arthritis, though there is limited widespread adoption of this use and limited supporting evidence.
Cultural Significance
It is reported to have Indigenous cultural significance, and again, little information is available on this topic.
Relationship to C. asiatica
Centella cordifolia is closely related to Centella asiatica, and their uses may be interchangeable. Centella asiatica is widespread across Australia, Africa, Asia, and North and South America, and has well-documented cultural, medicinal, and culinary uses.
Phylogenetic Study
A 2017 study published in Frontiers in Plant Science compared three Centella species (C. cordifolia, C. asiatica, and C. erecta) and found C. cordifolia to be genetically and chemically similar to C. asiatica.