What is "cockleburs"

Usage examples of "cockleburs".

Orgoch, her black hood shrouding her features, sat on a rickety stool, trying without great success to tease cockleburs from a lapful of wool shearings.

A few paces ahead, a jagged rectangle of light fell from a window onto a tangle of sea grass, cockleburs, and dirty sand.

Tearing through sea grass, cockleburs, wild azaleas, yucca plants, and a thousand species of lowland brier bushes, Joey ran full out ahead of us for what seemed like a couple hundred yards.