Indeed, eelgrass grows and extends through rhizomes, and for each rhizome, the stems grow out of the sediment. This is also a mode of propagation. Stems can grow by way of seeds and through the so-called vegetative propagation process, where the rhizomes extend within the sediment and expand the eelgrass surfaces. That is the most common form. It can also propagate by way of seeds, but the most common form is through vegetative propagation, i.e., through the spread of rhizomes.
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