A rhizomatous, perennial herb growing by streams and in calcareous flushes, requiring constant moisture but not waterlogged conditions. Mainly upland, but from near sea level at Durness (W. Sutherland) to 975 m on Ben Lawers (Mid Perth).
The distribution of T. pusilla appears to be stable. Since the 1962 Atlas its known range in Scotland has increased slightly, and it may still be present in squares for which there are only pre-1987 records. It was discovered new to science in 1671 in Berwickshire, and recorded from Charnwood Forest (Leics.) in 1828.
Circumpolar Arctic-montane element.
Light (Ellenberg): 8
Moisture (Ellenberg): 9
Reaction (Ellenberg): 7
Nitrogen (Ellenberg): 2
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 0.6
July Mean Temperature (Celsius): 11.6
Annual Precipitation (mm): 1964
Height (cm): 20
Perennation - primary
Life Form - primary
Clonality - primary
Count of 10km squares in Great Britain: 156
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: -0.32
Scarce Atlas Account
Tofieldia pusilla (Michaux) Pers.
Status: not scarce
T. pusilla is distinctly calcicole, requiring a reliably damp but not flooded situation; it cannot withstand much exposure. It grows in calcareous flushes from near sea-level at Durness to 915 metres at Coire Coulavie, Glen Affric. These flushes are usually narrow strips of grass and sedge around springs and beside burns, sufficiently far down the mountain to ensure constant water. The flushes are limited by taller vegetation on the drier zones along each side. At low altitude associates include Carex hostiana, Drosera longifolia, Eriophorum latifolium, Pinguicula lusitanica, Schoenus nigricans and Scorpidium scorpioides but in higher flushes it may be accompanied by Carex panicea, Juncus triglumis, Pinguicula vulgaris, Saxifraga aizoides, Thalictrum alpinum and even Carex saxatilis (McVean & Ratcliffe 1962).
T. pusilla is a perennial, growing from a rooting stock which gives rise to a cluster of sword-like leaves. Between June and September a taller inflorescence stalk is produced headed by a short raceme of a few small green-white flowers. These rarely open wide, have no nectary and are not long-lasting. Though tiny insects may pollinate them, self-pollination is more likely as the anthers dehisce inwards. Fruits and seeds are produced and vegetative reproduction also occurs by the formation of basal leaf clusters.
John Ray first found T. pusilla in 1671, two miles from Berwick. It was new to science. The precise spot is unclear but it could have been a flush beside the River Tweed. There having been railways, roads and many other developments since that time, there is no chance of its survival there, but in its now more well-known mountain haunts it is not threatened. The isolated record in Leicestershire is based on a nineteenth century specimen. There is no information about the habitat it came from.
T. pusilla is a circumpolar arctic-alpine plant. In Europe its only sites south of Britain are in the Alps and the Tatra mountains.