Hydrochariticeae Family of Tape Grasses

One Tape Grass of the Hydrochariticeae Family can be found in this website:

Clover Grass, Halophila decipiens. A representative of the Hydrochariticeae Family of Tape Grasses.

Phylogeny: Tape Grasses of the Hydrochariticeae Family are in the phylum Tracheophyta. Tracheophytes, unlike Bryophytes, are vascular plants that have tissues (phloem and xylem) that allow for the transport of water and nutrients within the plant via leaves, roots and stems. They have a cuticle (waxy layer to hold in water) and stomata (pores for gas exchange). Tracheophytes may either reproduce by seeds or spores. They are in the class Magnoliopsida, which are flowering plants that have branching leaf veins and flower parts in multiples of four or five. Other plants in this class include roses, oak trees and dandelions. This family is one of nine families in the order Alismatales. Alismatids grow in terrestrial, fresh water and marine environments. The Hydrochariticeae Family is comprised of nine genera and one hundred and thirty-five species. The family is also known as the Frog-bit Family and the Water Weed Family. The name Hydrochariticeae comes from the Greek words meaning “water grace” or “water beauty”.

Morphology: Tape Grasses are highly variable in form and habitat. While all species in this family are aquatic, they may grow in freshwater or marine habitats. They may grow partially or completely submerged, or floating. The leaves are simple and may be linear, ovate, or circular. The leaves may be basal, opposite, alternating or spiraling along the stem. The flowers are radially symmetrical with the petals and sepals in one or two whorls. The flowers are generally found between opposite bracts or within a forked spate-like bract. The fruit is berry-like, containing many small seeds. The rhizomes anchor the plant in the bottom substrate. Species in this family vary widely in size. Some species exceed 9 m (30 feet) in stem length and some exceed 1.5 m (4 feet 10 inches) in leaf length.

Habitat and Distribution: Tape Grasses grow in sand and mud substrates. Most grow at shallow depths, with few growing deeper than 10 m (33 feet), though some reach depths of 90 m (295 feet). They are found worldwide in tropical to temperate waters. Eight species of the Hydrochariticeae Family are found along the east coast of Mexico in the Gulf of Mexico and the Caribbean, and only one species is documented from Mexico’s west coast in the Pacific Ocean.

Reproduction: Hydrochariticeae are generally either male or female. The flowers grow at the water’s surface, where wind, insects, and water carry the pollen between plants. In some species, the male flowers break loose and drift until making contact with a female flower, and then exchange pollen.

Ecosystem Roles:  Tape Grasses are an import source of food and habitat for fish and other aquatic life. Tape Grasses are often used as decorative plants in aquariums. Some, such as Hydrilla, Hydrilla verticillata, are highly invasive and can displace native species, clog waterways, and disrupt water distribution systems. These invasive species can be very costly to eradicate once they are introduced.