Use of herbarium data to evaluate weediness in five congeners

A weed or not a weed? Many plant species grow somewhere on the continuum from undisturbed to very disturbed vegetation. Deciding on the degree of weediness is not an easy task, and is often based only on subjective observations. In a new study published in AoB PLANTS, Hanan-Alipi et al. compare data obtained during systematic field surveys with the habitats recorded on herbarium specimen labels, for a group of more-or-less weedy tropical species. They show that herbarium data reflect the collection bias favouring natural vegetation, but also, that the relative weediness hierarchy stays in place. The study is relevant for other ecological studies based on herbarium specimens.