(Acorus calamus) is a perennial herb that resembles cattails at first glance. Unlike cattails though, sweet flag does not grow to nuisance levels. The tall sword-like leaves produce an appealing spicy fragrance. A cigar looking spadix (seed-head) is a unique characteristic of sweet flag. This aquatic plant will grow in water up to 3 feet deep. Ecologically, sweet flag provides spawning habitat for fish and serves as an important stabilizer against erosion.