Welcome to Lake Tekapo, on New Zealand's South Island, where the colorful spikes of flowering Russell lupines transform the landscape each November and December. The plants' blooming heads, made up of clusters of pea-like flowers, can reach up to 60 inches. While photographers flock here to capture the varied hues of purple, blue, and yellow, these striking plants are controversial. Native to North America, they are considered an invasive species here, growing in dense stands and boxing out other flora. While these plants might be appealing to tourists, they can create a negative imbalance in the region's ecosystem.