Egeria densa

Planchon

Annales des Sciences Naturelles, Botanique sér. 3, 11: 80. 1849.

Common names: Water-weed
WeedyIntroducedIllustrated
Treatment appears in FNA Volume 22.

Stems 1–3 mm diam. Leaves whorled, recurved, 10–40 × 1.5–4.5 mm. Staminate spathes 2–4-flowered, 7.5–12 mm; pedicel to 80 mm. 2n = 46.


Phenology: Flowers summer–fall.
Habitat: Shallow waters of lakes and streams
Elevation: 0–500 m

Distribution

V22 512-distribution-map.jpg

Introduced; Ala., Ark., Calif., Colo., Del., Fla., Ga., Ill., Ind., Kans., Ky., La., Md., Mass., Miss., Mo., N.J., N.Mex., N.Y., N.C., Okla., Oreg., Pa., S.C., Tenn., Tex., Vt., Va., W.Va., Mexico, West Indies, Central America, native, South America, Europe, Africa, Asia, Australia

Discussion

Egeria densa is native to southeastern Brazil and has been widely sold in the aquarium trade, often becoming established in nature. Only staminate plants of E. densa have been observed outside its native range. Reproduction, then, occurs entirely by vegetative methods. No differentiated vegetative reproductive structures (turions, bulbils, etc.) are known (C. D. K. Cook and K. Urmi-König 1984b); however, the species is known to live temporarily under ice. The leaves of Egeria densa, which are only two cell-layers thick, are much used to demonstrate plant-cell structure and cytoplasmic streaming in introductory botany courses.

Selected References

None.

Lower Taxa

None.
... more about "Egeria densa"
Robert R. Haynes +
Planchon +
abbreviated +
sloping +
Water-weed +
Ala. +, Ark. +, Calif. +, Colo. +, Del. +, Fla. +, Ga. +, Ill. +, Ind. +, Kans. +, Ky. +, La. +, Md. +, Mass. +, Miss. +, Mo. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, Okla. +, Oreg. +, Pa. +, S.C. +, Tenn. +, Tex. +, Vt. +, Va. +, W.Va. +, Mexico +, West Indies +, Central America +, native +, South America +, Europe +, Africa +, Asia +  and Australia +
0–500 m +
pistillate +, staminate +  and pedicellate +
Shallow waters of lakes and streams +
sessile +  and 1-flowered +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
submersed +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
2-6[-16]-carpellate +
0 cm0 mm <br />0 m <br /> (?) +  and 8 cm80 mm <br />0.08 m <br /> (?) +
3-parted +  and 6-parted +
differentiated +
Flowers summer–fall. +
Annales des Sciences Naturelles, Botanique +
zygomorphic +  and actinomorphic +
mucilaginous +
fusiform +
2-4-flowered +  and staminate +
0.75 cm7.5 mm <br />0.0075 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
Weedy +, Introduced +  and Illustrated +
connate +  and distinct +
(0-)2-many +
unbranched +, branched +  and rooted +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
elongate +
not 2-fid +
Egeria densa +
species +
without evident stem +  and caulescent +
water +, marine +  and brackish +
pubescent +  and glabrous +