A new alpine puffball to the British Isles - Calvatia turneri
Post date: Jan 31, 2013 9:23:48 PM
During a routine examination of the puffball material in the Herbarium at the Royal Botanic Garden Edinburgh by Vincent Demoulin two collections labeled Lycoperdon molle were located and found in fact to be Calvatia turneri (Ellis & Everhart) Demoulin. It is significant that although the collections were made on the same day (8 ix 1984) and in the same general locality called The Cairnwell (Aberdeenshire), the sites in fact were rather different. One collection (Wat 17458) was from a grassy outcrop of sugar limestone which supported a whole range of arctic alpine vascular plants whilst the other (Wat. 18043) was found amongst the Least Willow Salix herbacea, on rather more peaty soil. Least willow is also know to be of arctic alpine distribution in the British Isles known in addition to sites in Scotland from mountainous regions of Wales and of the Lake District.
Calvatia turneri was originally described from Labrador (Ellis & Everhart), although it has subsequently been found in several additional sites in North America but all of a northern clime. All were habitats which were later described as arctic alpine by US authors. It is even known from the Falkland Islands (Watling, unpublished). In Europe it is probably better known as C. tatrensis Hollos described originally from Czechoslovakia. In Northen Europe C. turneri is documented from Iceland, Norway, Sweden and Finland.; and is extensively discussed by Morten Lange in his account of the larger fungi of Greenland. It was Demoulin in fact who demonstrated that these two puffballs were conspecific and Lycoperdon turneri was the earliest available name.
L. turneri is invariably found in open ground at relatively high altitudes or latitudes. The British collections follow this pattern, viz. closely cropped turf at 936m. The locality is well known for its outcrops of calacareous rocks imparting locally rich vegetation. The rock outcrops are schists hidden in some areas beneath rock debris and peaty deposits, which themselves support a typical acidic vegetation, characteristic of the majority of montane sites in Scotland. Such areas are colonized by Vaccinium spp., Mountain Azalea (Loiseleuria procumbens) and and Salix herbacea especially on the rather exposed areas
C. turneri can be identified by the relatively small fruit-bodies compared with other members of the genus in Europe viz. 2-6cm compared with C. excipuliformis (Scop.) Perdeck and C. utriformis (Bull.) Jaap and with an obconic sometimes plicate base. The exoperdiuim is granular or roughened with a browinish ornamentation composed of small spines often with connivent apices; no diaphragm is present thus resembling C. excipuliformis. Microscopically the capillitial threads are multiseptate, whereas those of C. excipuliformis and C. utriformis lack septa; slit-like pits are also absent unlike these two British species of Calvatia., There is little difference in spores characters, although on average the size of those of C. turneri might be slightly larger, reaching 6µm diam.
C. turneri is a true arctic-alpine puffball, whereas C. excipuliformis and C. utriformis may only occasionally be found in the Highlands; they occur more frequently at lower altitudes, the former sometimes also in woodland. It should be noted the very much larger C. utriformis has also been found on a Cairnwell ‘green’. The other arctic species, not yet recorded from the British Isles, are C. arctica Fed & Winge, with pyramidal warts, and C. cretacea (Berk.) Lloyd, with curved spines; the two species are often considered the same species by some N. American authors.
(For those less familiar with name changes I have used the generic name Calvatia throughout this contribution, nor the more recently defined Hankea even though recent molecular studies indicate they should be returned to Lycoperdon!)