Pennales
plural noun
Pen·na·les
\pəˈnā(ˌ)lēz\
Definition of Pennales
: an order of diatoms having a raphe or pseudoraphe and ornamentation of the valves always bilaterally arranged in relation to a line rather than to a point — compare centrales
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Origin and Etymology of pennales
New Latin, from Latin penna feather + New Latin -ales
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