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Ruppia maritima

L. (1753)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Monocots Order: Alismatales Family: Ruppiaceae Genus: Ruppia

ditchgrass, widgeon grass

Description

Key Characters:

Growth Form: Plants completely submerged rooted in seawater.

Stems: Stems greenish to brownish, capillary or slender, terete (cylindrical), (2–)4–10 dm long, many-branched, arising from creeping rhizomes.

Roots: Fibrous root system, also rooting at nodes.

Leaves: Leaves simple. Alternate, all similar, well-spaced or somewhat clustered. Blades linear, 10–100 mm long, 0.2–0.5(–1) mm wide. Apex rounded to obtuse. Base expanded into an open sheath. Margins entire. Only the midvein evident. Sheathing. Stipules membranous, sheathing and adnoate to leaf bases, sheath (2–)5–20(–70) mm long, ligule ± present.

Flowers: Flowers 2 per peduncle, axillary, peduncles at first short, elongating up to 3 dm long in fruit, often spiraling or coiling, during anthesis the peduncles and flowers concealed by the sheath of the uppermost stem leaves, the sheath ruptured by the elongating peduncle during anthesis as the flowers move to position slightly above the water surface. Flowers very small and inconspicuous, bisexual (perfect). Calyx (sepals) absent. Corolla (petals) absent. Stamens 2; anthers subsessile, dithecal, opening by longitudinal slits, the relatively large pollen sacs well separated on an expanded connective. Ovary superior, carpels (2–)4(–8), distinct, each carpel becoming elevated on a slender stipe in fruit so that the carpels of each flower form an umbelliform cluster; ovule 1, pendulous, campylotropous; stigma sessile or subsessile, peltate or umbonate.

Fruit: Fruit small; drupaceous; asymmetrically ovoid; borne on the slender stipe that continually elongates as the fruit matures; the stipe often twisted.; fruit symmetrical to asymmetrical; ovoid to pyriform; (1.5–)2–3(–4) mm long; the beak erect or curved; the elongate stipe 4–15(–35) mm long. Seeds without endosperm.

Ploidy: 2n = 16; 20; 24; 40

Habitat: Aquatic; occurring in brackish ponds and estuaries or similar man–made watercourses.

Elevation Range: 0–15 m.

Historical Distribution

Synonyms (51)

Buccaferrea maritima (L.) Lunell (1915)
Ruppia andina Phil. (1894)
Ruppia brachypus J.Gay (1849)
Ruppia brachypus subsp. bahusiensis Lindstr. (1920)
Ruppia brevipes Bertol. ex Griseb. (1864)
Ruppia cirrhosa subsp. longipes (Hagstr.) Á.Löve (1970)
Ruppia curvicarpa A.Nelson (1899)
Ruppia intermedia C.G.H.Thed. (1886)
Ruppia maritima f. aculeata Hagstr. (1911)
Ruppia maritima f. brevirostris C.Agardh (1823)
Ruppia maritima f. curvirostris H.St.John & Fosberg (1939)
Ruppia maritima f. pacifica H.St.John & Fosberg (1939)
Ruppia maritima f. pectinata Hagstr. (1911)
Ruppia maritima proles brachypus (J.Gay) Rouy (1912)
Ruppia maritima proles brevirostris (C.Agardh) Graebn. (1907)
Ruppia maritima proles curvicarpa (A.Nelson) Graebn. (1907)
Ruppia maritima subsp. brachypus (J.Gay) Bonnier & Layens (1894)
Ruppia maritima subsp. brevirostris C.Agardh (1823)
Ruppia maritima subsp. intermedia (C.G.H.Thed.) Piper & Beattie (1915)
Ruppia maritima subsp. obliqua (Griseb. & Schenk) Á.Löve & D.Löve (1961)
Ruppia maritima subsp. rostellata (W.D.J.Koch ex Rchb.) Asch. & Graebn. (1897)
Ruppia maritima subsp. rostrata (C.Agardh) Piper & Beattie (1915)
Ruppia maritima var. brachypus (J.Gay) K.Schum. (1894)
Ruppia maritima var. brevirostris (C.Agardh) Asch. & Graebn. (1897)
Ruppia maritima var. curvicarpa (A.Nelson) Fernald & Wiegand (1914)
Ruppia maritima var. exigua Fernald & Wiegand (1914)
Ruppia maritima var. floridana Graebn. (1907)
Ruppia maritima var. intermedia (C.G.H.Thed.) Asch. & Graebn. (1897)
Ruppia maritima var. japonica H.Hara (1983)
Ruppia maritima var. longipes Hagstr. (1911)
Ruppia maritima var. minor Mert. & W.D.J.Koch (1823)
Ruppia maritima var. obliqua (Griseb. & Schenk) Asch. & Graebn. (1897)
Ruppia maritima var. onondagensis Fernald & Wiegand (1914)
Ruppia maritima var. pacifica H.St.John & Fosberg (1939)
Ruppia maritima var. recta Moris (1827)
Ruppia maritima var. rostrata C.Agardh (1823)
Ruppia maritima var. subcapitata Fernald & Wiegand (1914)
Ruppia mexicana Hartog & Tussenbr. (2016)
Ruppia obliqua Griseb. & Schenk (1852)
Ruppia pectinata Rydb. (1900)
Ruppia rostellata W.D.J.Koch ex Rchb. (1824)
Ruppia rostellata var. brachypus (J.Gay) T.Marsson (1869)
Ruppia salina Schur (1866)
Ruppia spiralis subsp. longipes (Hagstr.) Á.Löve & D.Löve (1961)
Ruppia spiralis subsp. transsilvanica (Schur) Nyman (1882)
Ruppia subsessilis Thwaites (1864)
Ruppia taquetii H.Lév. (1911)
Ruppia transsilvanica Schur (1860)
Ruppia trichodes Durand (1847)
Ruppia zosteroides Lojac. (1909)
Zannichellia pedunculata Fuss (1854)

Uses and Culture

USES

Natural History

Statewide Status

Indigenous

Island Status

Ni'ihau(Incl. Lehua) Indigenous
Kaua'i Indigenous
O'ahu Indigenous
Molokai Indigenous
Lana'i Indigenous
Maui Indigenous
Hawai'i Indigenous

Dispersal Agents


Pollinators

Bibliography

Name Published In: Sp. Pl.: 127 (1753)

Other References

Wagner et al. 1990:1609 (Ni, K, O, Mo, L, M, H)

Occurrences (146)

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