Cyperus papyrus (Cyperaceae). Papyrus. This is an aquatic plant. It is easy to grow if you can provide it with enough water. The rhizomes grow under water and send out large tall flowering stems that can be up to 4m. Each is topped by a dense cluster of thin, bright green, shiny stalks, which resemble a feather duster when young. Sowing : Sow seeds in summer in wet conditions. Locality : Ex Hort. Date of harvest : May 2018.