Vallisneria americana Michx. - Tapegrass


 

|  back  | forward |

Vallisneria americana - (image 1 of 2)

 

Taxonomy

Family: Hydrocharitaceae

Habitat

Shallow, calm water of lakes and streams.

Associates

 

 Distribution

Nova Scotia and Quebec west to MN and SD, south to tropical America and scattered elsewhere.

Morphology

Submersed stoloniferous perennial from a short erect crown. Leaves thin, ribbon-like, to 2 m long and 10 mm wide. Dioecous; staminate scape stout, the flowers minute (1-1.5 mm wide) with 3 sepals, 1 petal, and 2 stamens, numerous, in a head subtended by an ovoid, bivalved spathe; pistillate flowers white, with 3 sepals 3.5-6.5 mm, 3 petal-vestiges, 3 stamen vestiges (staminodia), and 3 broad bifid stigmas, mostly solitary, sessile, in a tubular, apically bifid spathe on slender scape long enough to reach the surface. Fruit elongate, cylindric, 5-12 cm, indehiscent, with many seeds.

Notes

Flowers July to September

Wetland indicator: Obligate

Also called Eel Grass. The male flowers separate individually and float to the surface. After pollination the pistillate scape coils to retract the fruit. 

References

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY

 

Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region.
Indiana Academy of Science. The Morton Arboretum. Lisle, Illinois.

 


Home

 

 Michael Hough 2009