Maiden’s Hair aka Chlorodesmis fastigiata is a marine algae and plankton species. It’s also commonly known as turtle weed, though Maiden’s hair is clearly superior in eliciting interest. It definitely beats what I would have named it, patchy-water-grass, but while illustrating this one I also thought it could be kicked up a notch to Mermaid’s hair. That sound pretty exotic*.
Of course there already are things called water grass and even mermaid’s hair –but be warned, just like a real mermaid, house rules apply: you can ogle them all you want but if you touch them, they’ll mess you up.
*plus what’s this ‘maiden’ doing under water? and what happened to the rest of her? the horror stories write themselves.