Short answers, pulled from the story.
Typha is a genus of about 30 species of monocotyledonous flowering plants in the family Typhaceae. The plants are aquatic or semiaquatic perennials found across wetland habitats, primarily in the Northern Hemisphere. Their common names include cattail, bulrush, reedmace, cumbungi, and raupō depending on the country.
Preserved starch grains found on grinding stones in Europe show that Typha rhizomes were being eaten at least 30,000 years ago. The rhizomes are starchy and nutritious, with a protein content comparable to maize or rice, and can be processed into a flour yielding 266 kilocalories per 100 grams.
The United States Navy used Typha down as a substitute for kapok in life vests and aviation jackets during World War II. Even after 100 hours of submersion, the buoyancy of the Typha-filled garments remained effective.
Cossack asparagus is the tender white heart found inside the rind of young Typha stems. It is eaten raw or boiled and has been historically popular among Cossacks in Ukraine.
Typha species displace native sedges and shrink wet meadows in many areas, from the Great Lakes to the Everglades, largely due to altered wetland hydrology and increased nutrient levels. An introduced or hybrid Typha species may also be contributing to the spread. The most effective control strategy is mowing or burning the stalks followed by prolonged flooding.
Pungapunga is a traditional Maori bread made from the pollen of Typha orientalis. The pollen is collected during mid-summer when the male flowers are mature and used as a flour supplement or thickener.