Charophytes from the warm springs of Svalbard

Two of Svalbard's Trollkjeldane (Troll Springs) have a luxuriant vegetation of charophytes. This article is based on material collected in the Trotlkj eldane by Sissel Aarvik, of the Office of the Sysselmann (Governor) of Sval bard, on 28 August 1992 and 16 August 1993. Chara canescens is described, b ased on living material. The Svalbard specimens have been named Chara canes cens f. spitsbergensis comb, nov., which is synonymous with Chara aspera f. spitsbergensis Nordstedt. An imperfect charophyte is described here as a n ew subspecies of C. canescens: Chara canescens subsp. hoelii, named after A dolf Heel, who first collected specimens of this subspecies. It is believed that this subspecies originates from Chara canescens, presumably by a gene tic reorganization or a mutation of the species. A new subspecies is justif ied because of the ecorticate internodes, the incomplete or lacking cortex of the branchlets, the occurrence of accessory branchlets and the special b ulbils found in this taxon. These are interpreted as characteristics with p ositive selective value in the special environment of the spring, where ase xual reproduction by bulbils presumably has the same selective value as the parthenogenic reproduction by oospores in Chara canescens f. spirsbergensi s. In a growth experiment, the best growth of C. canescens f. spitsbergensis f rom the springs was obtained in water with relatively low salt content. Growing tourism in Svalbard threatens to the springs; more active protectio n must be evaluated. There is also an urgent need to survey the springs in more detail.