Complex sentence: The alga has a stem (rhizome) which spreads horizontally just above the seafloor, and from this stem grow vertical fern-like pinnae, whose blades are flat like yew ("Taxus "), hence the species name"taxifolia".
Split into simpler sentences: The alga has a stem (rhizome) which spreads horizontally just above the seafloor. From this stem grow vertical fern-like pinnae, whose blades are flat like those of the yew ("Taxus "), hence the species name"taxifolia".