“+ noun
Usage: capitalized
Etymology: New Latin, from phyll- + Greek siphōn siphon, tube
: a genus (the type of the family Phyllosiphonaceae of the order Siphonales) of filamentous green algae that live as intracellular parasites of plants of the family Araceae (as the jack-in-the-pulpit) and cause yellowing and discoloration of the leaves and stems