I was born in Maryland, and attended both Anne Arundel Community College and St. Mary's College of Maryland, where I graduated with a BS in Biological Sciences. I became excited about algae, and diatoms in particular, during amazing field experiences at the University of Michigan Biological Station and Iowa Lakeside Lab. I received a MS degree (Biological Sciences) from Bowling Green State University and a Ph.D. (Natural Resources) from the University of Michigan, where I also did a post-doctoral fellowship.

I held the G Dallas Hanna Chair in Diatom Studies at the California Academy of Sciences for 20 years, where I also was the Director of Research and Executive Director. Currently I am the Director of the Natural History Museum and Professor in the Department of Ecology and Evolutionary Biology at the University of Colorado, Boulder, and I teach at the University of Michigan Biological Station during summers.

I am interested in the taxonomy, systematics, evolution and ecology of diatoms, particularly freshwater taxa. I also study the biogeography of diatoms, with an eye to documenting what species grow where, what patterns of distribution there might be and what explanations we might have to account for those patterns.

Species contributed

Amphora copulata | Amphora ovalis | Amphora pediculus | Aneumastus pseudotusculus | Bacillaria paradoxa | Caloneis bacillum | Caloneis silicula | Cocconeis klamathensis | Cocconeis rugosa | Craticula buderi | Cymatopleura solea | Cymbella janischii | Cymbellonitzschia diluviana | Decussata placenta | Denticula tenuis | Diadesmis confervacea | Diatomella balfouriana | Encyonopsis microcephala | Encyonopsis subminuta | Fallacia pygmaea | Frustulia amphipleuroides | Frustulia crassinervia | Frustulia krammeri | Frustulia saxonica | Frustulia vulgaris | Gomphoneis eriense | Gomphoneis eriense var. angularis | Gomphoneis eriense var. apiculata | Gomphoneis eriense var. variabilis | Gomphoneis herculeana | Gomphoneis herculeana var. abundans | Gomphoneis herculeana var. lowei | Gomphoneis mammilla | Gomphoneis minuta | Gomphoneis olivaceum | Gomphoneis pseudo-okunoi | Gomphoneis septa | Gomphoneis trullata | Gomphonema acuminatum | Gomphonema apicatum | Gomphonema brebissonii | Gomphonema coronatum | Gomphonema elongatum | Gomphonema kobayasii | Gomphonema mexicanum | Gomphonema pusillum | Gomphonema pygmaeum | Gomphonema stoermeri | Gomphonema truncatum | Gomphonema ventricosum | Gomphosphenia grovei | Gomphosphenia lingulatiformis | Halamphora montana | Halamphora veneta | Hannaea arcus | Hygropetra balfouriana | Mastogloia albertii | Mastogloia grevillei | Mastogloia lacustris | Meridion circulare | Navicula rhynchocephala | Navicula rostellata | Navicula salinarum | Navicula vulpina | Nitzschia acicularis | Nitzschia amphibia | Nitzschia balcanica | Nitzschia brevissima | Nitzschia clausii | Nitzschia columbiana | Nitzschia communis | Nitzschia desertorum | Nitzschia exilis | Nitzschia filiformis | Nitzschia fonticola | Nitzschia fonticoloides | Nitzschia innominata | Nitzschia liebethruthii | Nitzschia linearis | Nitzschia microcephala | Nitzschia minuta | Nitzschia oregona | Nitzschia palea | Nitzschia palea var. debilis | Nitzschia palea var. tenuirostris | Nitzschia paleacea | Nitzschia perminuta | Nitzschia reversa | Nitzschia sigma | Nitzschia sinuata var. tabellaria | Nitzschia valdecostata | Pleurosira laevis | Rexlowea navicularis | Rhopalodia gibba | Rhopalodia musculus | Sellaphora bacillum | Tabularia fasciculata | Thalassiosira lacustris | Thalassiosira weissflogii | Tryblionella calida | Tryblionella hungarica

Genera contributed

Simonsenia