The Purple Heron; unknown artist; Undated; Watercolor; with pen; in brown ink; gray ink; gouache; and graphite; on medium; moderately textured; cream; wove paper; mounted on; very thick; moderately textured; cream; cardboard; Mount: 20 11/16 x 26 9/16 inches (52.5 x 67.5 cm) and Sheet: 18 1/4 x 25 1/8 inches (46.4 x 63.8 cm); animal art; birds; heron; ornithology; purple; science; taxonomy (discipline)