The species favours wet, acidic and nutrient poor soils, thriving in Sphagnum-dominated bogs, but also peaty grasslands.
[7] It has a wide range across the Northern Hemisphere, extending from the inland wetlands of North America, across Europe to the Korean Peninsula.
[3] Each leaf is differentiated into a green or straw coloured sheath, which hugs the stem, and a grey/green blade, which is flat and slender (0.7–2 mm) and tapers to a blunt tip.
[11] This reflects its different life history to many other sedges – R. alba loses all but the basal overwintering bud during the winter, while most other species retain and store nutrients in well-developed rhizome and root structures.
Rhynchospora alba favours acidic, nutrient poor conditions and is found across a range of wetland environments.
[4] This is likely related to the much lower levels of interspecific competition experienced by R. alba in these bogs than other sedges in more grass-dominated environments.
[17] It is much less dominant of more established communities, however, as it is less capable of outcompeting sedge species with more developed root and rhizome systems.
[4][17] Rhynchospora alba is wind-pollinated and wind-dispersed,[12][13] so has few close interactions with insect pollinators, but is a major food source for a number of bog-dwelling species, such as Paraphlepsius leafhoppers in the US.
[18] Although most species of Rhynchospora are found in tropics,[15] R. alba is more restricted to the higher latitudes of the Northern Hemisphere, where climatic conditions favour the establishment of bogs and fens.
[8][13][19] It has a wide boreal distribution and is commonly found in the US (north of California and South Carolina[12]), Canada, Europe, the Caucasus, China, Japan and the Korean Peninsula.
[10][11] Owing to the high biodiversity and significant morphological similarity seen across the sedges, R. alba has a somewhat complex taxonomic history.
The species was first described by Carl Linnaeus in 1753, and was classified in the same genus as bog rushes (due to similarities in inflorescence) under the binomial name Schoenus albus.
[7] Rhynchospora alba (L.) Vahl is the current accepted species name for the white beak-sedge, but there has been considerable contention around its classification over the last 200 years[10] (see below).
[22] Bentham and Hooker tried to resolve this conflict by splitting Rhynchospora into two subgenera – Diplostylae and Haplostylae – based on the branching pattern of the style.
These synonyms were identified in monographs by Kükenthal and Gale,[10][15] as well as more recent studies by Kew's World Checklist of Selected Plant Families.
[28] Molecular studies within the Rhynchosporae, however, reveal that Kükenthal's widely accepted classification holds less well – neither Haplostylae nor Diplostylae are monophyletic, and there appear to be multiple conversions between bifid and non-bifid styles throughout the genus.
As such, it is not known if regional population declines are eroding genetic and subspecies diversity, nor whether some sections of the species range are of greater conservation concern than others.