Definition of Protosiphon
: a genus (the type of the family Protosiphonaceae) of unicellular multinucleate freshwater green algae consisting of a single form (P. botryoides) that is broadly tubular or more or less balloon-shaped and grows often confusingly mingled with Botrydium attached to mud by a single rarely branching rhizoid
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Origin and Etymology of protosiphon
New Latin, from prot- + Greek siphōn siphon, tube, pipe
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