Chances are you don’t give much thought to seaweed unless you’re at the beach, or perhaps when you’re considering a dinner menu. But the thousands of seaweed species around the world are a key part of our coastal ecosystems.

Seaweeds photosynthesize, provide food and shelter for marine animals, stabilize the coastlines, and even contribute to making your ice cream creamier (through an ingredient called carrageenans, extracted from red seaweeds in the Rhodophyceae family). Increasingly, they’re also being investigated as a source of biofuels and as biological factories, due to their fast-growing nature.

Dr. John Bothwell, a phycologist at Durham University in the UK, has written a book in praise of seaweeds. In Seaweeds of the World: A Guide To Every Order, he highlights beautiful, unusual, and important species from each of the three seaweed lineages—green, red, and brown. In this segment, he talks with SciFri’s Charles Bergquist about some of his favorite species, where the seaweeds fit into the web of life, and the importance of seaweeds to the global ecosystem.

Scientists have collected DNA samples of thousands of new fungus species over the past several decades. These fragments of fungal DNA are found nearly everywhere—in soil, decomposing logs, water, and even in the air. Mycologists have enough data to place these new species within the fungal family tree, but haven’t collected physical samples of them or been able to grow them in a lab. This means that according to the International Code of Nomenclature for algae, fungi, and plants, these new species cannot receive scientific names.

How can you understand a fungus that has no name? SciFri producer Shoshannah Buxbaum talks with fungal taxonomist Dr. David Hibbett, professor of biology at Clark University, about a proposal to give these “dark fungi” scientific names, and why naming living things might help us better protect the Earth’s biodiversity.

Transcripts for each segment will be available the week after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.