Natives and archaeophytes have declined consistently since the 1950s, while neophytes have steadily increased

Relative median frequency of plant species

0.5

0.4

Native to Britain

0.3

Neophyte

Modern introductions

0.2

Archaeophyte

Ancient introductions

0.1

1950

2019

Archaeophyte

Ancient introductions

Neophyte

Modern introductions

Native to Britain

0.5

0.4

0.3

0.2

0.1

1950

2019

1950

2019

1950

2019

Guardian graphic. Source: The Botanical Society of Britain and Ireland. Plant Atlas 2020. Note: trend lines are smoothed curves based on estimates from multi-year periods