Saturday, July 04, 2015 
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The Montana Diatom Collection


The Montana Diatom Collection consists of over 14,000 permanent slides and 2,000 vials of cleaned material representing diatom collections from over 5,000 localities throughout the Northwest United States. The MDC is in two parts: (1) the main working collection at the curator’s residence in Helena and (2) 4,000 replicate slides at MONTU made from samples collected since 1999. The MDC contains TYPES of diatom species. (Click here for an Excel file of diatom types in the MDC.)



Diatoms (Kingdom Plantae: Division Bacillariophyta) are eukaryotic photosynthetic microbes distinguished by transparent cell walls composed of hydrated silica (SiO 2) or opal. The cell wall consists of two overlapping halves that are intricately ornamented in patterns characteristic of each species. Diatoms are at the base of nearly all aquatic food chains—the slippery film on rocks in streams is composed mostly of diatoms. Diatoms first appeared in the Cretaceous period at about the same time as flowering plants. About one-third of the diatom species in the Northwest remain to be named and described. (Click here for a list of publications based on the Montana Diatom Collection.)

Diatoms of the U. S. website, an online flora at: http://westerndiatoms.colorado.edu/



Navicula aurora

Cyclotella antiqua