nasturtium
Tropaeolum majus L.
Garden nasturtium spreads on fleshy, hairless stems that can trail over the ground or scramble through nearby vegetation. Its round leaves look like small shields: the long stalk joins the underside within the blade rather than at its edge, and veins radiate outward from that attachment point. Leaf blades commonly measure about 4–15 cm across. Weeds of Australia: Tropaeolum majus
Botanical name
Tropaeolum majus L. is accepted as a species in Tropaeolaceae. Kew treats it as a cultigen from Peru and suggests, without certainty, ancestry from T. ferreyrae × T. minus. Kew Plants of the World Online: Tropaeolum majus
Recognizing the plant
Large flowers, roughly 2.5–7 cm wide, can be yellow, orange or red. Five petals surround the center, while one of the five sepals extends backward into a long nectar spur. Eight stamens sit inside the flower. The rounded fruit divides into three ribbed, one-seeded segments. Plants can reproduce through seed and through detached pieces of stem, a useful feature to recognize where garden escapes establish. Weeds of Australia: Tropaeolum majus
Bloom window
Naturalized populations in Australia
Australian accounts describe flowering mainly in spring, with flowers also appearing in summer and autumn. Weeds of Australia: Tropaeolum majus
Native range
Kew traces this cultivated-origin plant to Peru. Naturalized populations are now widespread; in coastal southern and eastern Australia they occupy roadsides, waterways, waste ground and disturbed bushland. Kew Plants of the World Online: Tropaeolum majusWeeds of Australia: Tropaeolum majus
Botanical sources
Reviewed 2026-10-11. Seasonal development varies with location and growing conditions.