AMERICANARUM DIATOM ARUM EXSICCATA: FASCICLE II (CANA), VOUCHER SLIDES REPRESENTING 34 LAKES, PONDS AND STREAMS FROM ELLESMERE ISLAND, CANADIAN HIGH ARCTIC, NORTH AMERICA

Abstract

Fascicle II of the Americanarum Diatomarum Exsiccata is comprised of 52 diatom slides from 34 lakes, ponds, and streams located on Ellesmere Island in the Canadian High Arctic. This exsiccata has been distributed to 16 museums and collections around the world. Diatom slides were prepared from sediments, mosses, and plant stems collected in aquatic systems ranging in size from small ponds (198 m²) to large lakes (218 ha). Present pH levels range from 7.2 to 8.3 and conductivities range from 79 to >2000 μS cm⁻¹. A total of 217 taxa were identified, along with 65 unknown forms that were catalogued and photographed. The most common taxa were Achnanthes minutissima Kützing, Achnanthes sp. [cf. petersenii Hustedt], Diatoma tenue Agardh, Cymbella descripta (Hustedt) Krammer & Lange-Bertalot, C. microcephala Grunow, C. minuta Hilse ex Rabenhorst, Denticula kuetzingii Grunow, Eunotia sp. [cf. praerupta Ehrenberg], Fragilaria sp. [cf. vaucheriae (Kützing) Petersen], Navicula cryptocephala Kützing, N. vulpina Kützing, Nitzschia frustulum (Kützing) Grunow, N. perminuta (Grunow) M. Peragallo, N. perminuta var. 1, Staurosirella pinnata (Ehrenberg) Williams & Round, Staurosirella pinnata var. intercedens (Grunow in Van Heurck) Hamilton.