This montane, rhizomatous herb occurs in rather open wet turf in marshes and flushes and by lakes and streams, usually on base-rich soil and often over limestone. It is often found with a range of other less common montane calcicoles in bryophyte-rich habitats. From 150 m near Pitlochry (E. Perth) to 880 m on the Ben Alder range (Westerness).
J. alpinoarticulatus has been much confused with variants of J. articulatus, and sometimes grows and hybridises with them. New finds in recent years are due to better identification skills rather than to natural range extension.
Circumpolar Boreal-montane element.
Count of 10km squares in Great Britain: 53
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: -0.12
Scarce Atlas Account
Juncus alpinoarticulatus Chaix
A rare, northern and sub-montane to montane species of base-rich mires. In the Scottish Highlands it is a plant of open, base-rich flushes, lake margins and mossy marshes, growing with a wide variety of species including Carex capillaris, Juncus triglumis, Saxifraga aizoides, Thalictrum alpinum, Tofieldia pusilla and at two sites Schoenus ferrugineus and Kobresia simpliciuscula. In the Southern Uplands all these species are absent and Parnassia palustris is conspicuous. In Teesdale, it grows principally in open vegetation at the base of hummocks of the moss Gymnostomum recurvirostrum with most of its Highland associates. Here the soil is shallow, saturated and resting directly on solid rock (Clapham 1978). It occurs on limestones of the Carboniferous, Dalradian and Moine series, but is on calcareous Silurian greywackes and shales in the Southern Uplands. It ascends to 880 metres on the Ben Alder range but is found between 190 metres and 365 metres in the Southern Uplands (Corner 1970).
J. alpinoarticulatus is a rhizomatous perennial. Seed is set in abundance but little is known of its reproduction.
This species has been under-recorded in the past, and many new sites have been discovered in recent years. Populations in the Scottish Highlands appear to be stable, but those in the Southern Uplands are under continual threat from coniferisation and some populations have already been lost. The flooding of Cow Green in Upper Teesdale destroyed some of its sites there.
This species is widespread in the boreal zone of Europe, Asia and North America. In Europe it extends south in the mountains to Spain. Italy and the Balkans.
Three subspecies are known, of which subsp. alpinoarticulatus alone occurs in the British Isles. J. nodulosus is probably only a variety of this subspecies but more taxonomic work is needed. Hybrids occur very rarely with J. articulatus.
R. W. M. Corner
PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.