Papyrus is a sedge (family Cyperaceae) is considered as a perennial plant by us here in Chattanooga although it is zoned 8-11 (we're zone 7). Papyrus is related to the grass family (sometimes considered ornamental grass). However, a sedge is defined as a grass-like plant with triangular stems and inconspicuous flowers, usually growing in wet areas. 

The triangular stem grows out of a clump; under the stem lies a thick mass of rhizomes—the means by which the plant spreads. The greenish-brown flowers bloom in summer, then give way to the fruits that look somewhat like a nut. It's a great looking plant that can work in pots, landscape and pond areas. It can be grown in part to full sun and likes average soil moisture. At maturity, it reaches 18-24 inches both tall and wide.