Acaena magellanica, commonly called buzzy burr or greater burnet, is a species of flowering plant whose range includes the southern tip of South America and many subantarctic islands.

Acaena magellanica is a perennial, mat-forming plant with creeping stems, up to 14 cm (6 in) high.

[2] In South Georgia, Acaena magellanica may cover the ground in dense patches.

It is deciduous, and when the leaves are shed, mosses like Tortula robusta, which grows underneath, flourish.

[4] When the rabbit was eradicated, A. magellanica and other forbs failed to recover because years of herbivory had depleted their seed banks, and introduced species such as annual meadow grass (Poa annua), mouse-ear chickweed (Cerastium fontanum) and dandelion (Taraxacum officinale) out-competed them.