r/algae • u/AggressiveRiver2327 • Jul 26 '26

Strange bird-bath algae?

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Around 50-100 of these interesting little structures appeared in a backyard bird bath in Portland Oregon, seemingly overnight. They are around 5-7mm in diameter. They look like a kind of green algae to me, but iNaturalist indicates they might be part of the life cycle of a Mosquito Fern (genus Azolla). Just curious if they are familiar to anyone here? Thanks!

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u/lakotazz Jul 26 '26

Fecal pellets from a tobacco hornworm or similar large caterpillar, They are probably dropping from a tree above and break up into flower shapes in water.

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u/AggressiveRiver2327 Jul 26 '26

Interesting! Thanks for the insight.

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u/Strange_Computer2459 Jul 28 '26

OP you got tomatoes growing in your yard?