Ruppia cirrhosa
Ruppia maritima
ditch grass, spiral ditch-grass
beak ditch-grass, ditch grass, ruppie maritime, sea ditch-grass, spiral ditch-grass, western ditch-grass, widgeon-grass, wigeongrass
to 55 cm × 0.1–0.3 mm.
to 50 cm × 0.1–0.7 mm.
3.2–45.1 cm;
blade 0.2–0.5 mm wide, apex acute.
6–10.5 cm;
blade 0.3–0.5 mm, apex ± obtuse.
peduncles with 5–30 coils, 30–300 × 0.5 mm.
peduncles with 0–3[–4] coils, 0.5–16.5 × 0.5 mm.
pistils 4–6.
pistils 4–8.
1.5–2 × 1.1–1.5 mm;
gynophore 2–3.5 cm;
beak lateral, erect, 0.5–1 mm.
1.8–2 × 0.7–1.5 mm;
gynophore 1.2–1.9 cm;
beak terminal, slightly recurved, 0.6–1 mm.
= 40 (Europe).
= 16.
Ruppia cirrhosa
Ruppia maritima
Ruppia spiralis Linnaeus has occasionally been used for this taxon in North America. Linnaeus, however, had never published that name (J. T. A. Verhoeven 1979). Ruppia cirrhosa is, indeed, the correct name for the taxon (J. C. Gamerro 1968).
An implication that the North American material with long, spiraling peduncles is different from the European material of Ruppia cirrhosa stems from the statement that R. occidentalis occurs in inland lakes (J. T. A. Verhoeven 1979). No differences between European R. cirrhosa and the North American material are listed, however. In fact, a comparison of the Verhoeven's descriptive discussions for of R. cirrhosa (Verhoeven 1979) with the North American material shows that the two are the same. The genus should be studied on a worldwide basis. Until further studies indicate otherwise, I am considering North American and European material to be conspecific.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
No specimens have been seen from Washington, D. C., but the species is to be expected there.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
IL Wildflowers, 
KS Wildflowers, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
- Local floras: BC, CA, OR, WA
- Local Web sites: CalFlora, CalPhotos, Flora NW,
Go Botany, 
LA Plants, 
MD Biodiversity, PNW Herbaria - WildflowerSearch
- iNaturalist (observations)
- USDA Plants Database
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
