Remarkably unremarkable: Tecticornia enodis (Chenopodiaceae), a new samphire with smooth seeds from the arid interior of Western Australia

Abstract

With their succulent, bead-like stems and uncharismatic, sac-like flowers with a single anther and ovary, salt-loving species in the genus Tecticornia Hook.f. (subfam. Salicornioideae Ulbr., Chenopodiaceae) have few obvious diagnostic features. Indeed, they could be considered a ‘taxonomic nightmare’, a phrase coined by experts to describe other species in the closely related genus Salicornia L. (Kadereit et al. 2007). Commonly known as samphires, these plants can exhibit considerable morphological plasticity when grown under different conditions (Ungar 1987). They are also genetically problematic as DNA sequence variation is relatively low, likely due to the relatively recent evolution and rapid radiation of the group. The presence of hybrids and polyploids pose further significant challenges (Shepherd & Yan 2003; Shepherd et al. 2004; Kadereit et al. 2006; Piirainen et al. 2017). Seed coat ornamentation is often useful for identification, particularly among the soft-fruited species of the genus (Wilson 1980; Shepherd et al. 2005); however, seeds are seasonally limited, very small (usually less than 2 mm long), and best observed under a microscope. As a result, the accurate identificaion of plants, particularly sterile specimens, can be very challenging.