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Featured Plant

July

Nuphar polysepala

Profile:

Scientific name: Nuphar polysepala

Family: Nuphar polysepala

Plant type: Aquatic perennial

Environment: Ponds, lakes, slow moving water

About

The great yellow pond-lily (Nuphar polysepala) is, as the common name suggests, an aquatic perennial plant in the water lily family native to western North America. The species is found in ponds and lakes at elevations ranging from sea level to over 12,000 ft.

Nuphar polysepala has a variety of adaptations that allow it to thrive in its watery habitat. Unlike most terrestrial plants, the large, heart-shaped leaves of the great yellow pond-lily only have stomata on their surface. Stomata are specialized pores that regulate the flow of gases in and out of the leaf. The leaves also have a waxy coating, which waterproofs the leaves, allowing the stomata to function.

Though the most noticeable parts of the great yellow pond-lily are the large leaves and bright yellow flowers there is also lots of activity happening below the surface. These structures are attached to partially to fully submerged stems that grow from a large, fleshy rhizome, or a horizontal stem, that roots into the bottom of the body of water. These stems have specialized spongy aerenchyma tissues, which have large amounts of pore space. This allows for oxygen to be more easily moved from plant parts above the water to underwater tissues to support cellular respiration.

The great yellow pond-lily is also able to respire without oxygen, a process known as anaerobic respiration. This intricate chemical process produces ethanol, which is harmful to plants and is excreted quickly to avoid damage. In order to do this the ethanol is evaporated and moves through the aerenchyma cells in the plant’s stem and out through the flower.

The species has ethnobotanical significance to indigenous peoples of its native range, such as the Klamath and Modoc, who use various parts of the plant in traditional medicinal practices to treat a variety of ailments. The seeds and rhizomes of the plant were also used as an important food source.

IN BLOOM CONTRIBUTORS: Text and Photos by Victoria Stewart 

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