Leaves are opposite, lanceolate to elliptical in shape, unlobed, and sessile. Bur-marigold spreads readily by seed and is potentially useful in mass plantings and for erosion control. Sky flower is a member of the Hydrophyllaceae or Waterleaf family. It is a perennial herb, growing in and around shallow water in swampy woodlands, marshes, and ditches. The plant is 0.60 to 0.80 m in height with smooth or pubescent stems, and alternate, elliptic to lanceolate shaped leaves.
Individual flowers are bisexual with five petals each.
Seed pods contain numerous, extremely small, oval-shaped seeds that germinate readily, although new plants are produced from rhizomes as well. Sky flower has been successfully grown in standard 2-gallon containers for several years at the Fort Lauderdale Research and Education Center. East Indian Hygrophila, first introduced into Florida in the 1950s for use in the aquatic ornamental industry, is native to the East Indies and a member of the Acanthaceae family. Generally, East Indian Hygrophila prefers riverine habitats, growing profusely as a rooted, submersed, herbaceous perennial with square, decumbent stems and short stalks. Leaves are lanceolate or lance-elliptic, opposite and 2.0 to 7.0 cm in length.