A practical technique for preserving specimens of duckmeal, Wolffia (Araceae)

Abstract

Making identifiable herbarium vouchers of the minute aquatic vascular plant duckmeal, Wolffia (Lemnoideae; Araceae) has typically required plants to be preserved in transparent, space-consuming vials that are fragile, difficult to work with, and labourious to prepare. An alternative technique for dry-mounting Wolffia within a layer of transparent, acid-free glue presents a promising alternative. Although the largely water-filled individual plants still compress substantially, this preparation technique results in specimens that retain their colour, size, and, most important, their shape. This greatly enhances the possibility of confident identification and simplifies both specimen preparation and storage.