Store › Giant Kelp Poster Image 1 of 1 Giant Kelp Poster $45.00 18x24 Poster illustrating the life cycle of Giant Kelp, Macrocystis pyrifera in the waters of California’s Central Coast! Quantity: Add To Cart Added! 18x24 Poster illustrating the life cycle of Giant Kelp, Macrocystis pyrifera in the waters of California’s Central Coast!