Vertebrata nigra vs. Polysiphonia stricta

Vertebrata nigra & Polysiphonia stricta in Maine

Both are found on sheltered to exposed shores in the low intertidal to subtidal zones and in tidepools.

Vertebrata nigra is common in Southern Maine and rare Downeast northward. It grows on rock.

Polysiphonia stricta is occasional to abundant all along the Coast of Maine, as a perennial in northern regions and a winter annual in the south. It grows on rock, shells, epiphytic* on other algae, or on wood pilings and docks.

Molecular data indicates that Polysiphonia stricta represents a complex of cryptic species.

*Epiphytic – Growing on the surface of other seaweeds.