1.
Nasturtium officinale
W. T. Aiton in W. Aiton and W. T. Aiton, Hortus Kew. 4: 110. 1812.
Sisymbrium nasturtium-aquaticum
Linnaeus, Sp. Pl. 2: 657. 1753;
Rorippa nasturtium-aquaticum
(Linnaeus) Hayek
Plants
glabrous throughout or sparsely pubescent.
Stems
1-11 (-20) dm.
Cauline leaves:
petiole not winged, base auriculate; blade 3-9(-13)-foliolate, (1-) 2-15(-22) cm; lateral leaflets sessile or petiolulate, rachis not winged, blade smaller than terminal; terminal leaflet (or simple blade) suborbicular to ovate, or oblong to lanceolate, (0.4-)1-4(-5) cm × (3-)7-25(-40) mm, base obtuse, cuneate, or subcordate, margins entire or repand, apex obtuse.
Fruiting pedicels
divaricate or descending, straight or recurved, 5-17(-24) mm.
Flowers:
sepals 2-3.5 × 0.9-1.6 mm; petals white or pink, spatulate or obovate, 2.8-4.5(-6) × 1.5-2.5 mm, (base to 1 mm), apex rounded; filaments 2-3.5 mm; anthers 0.6-1 mm.
Fruits
(0.6-)1-1.8(-2.5) cm × (1.8-)2-2.5(-3) mm; ovules (28-)36-60 per ovary; style 0.5-1(-1.5) mm.
Seeds
biseriate, reddish brown, ovoid, (0.8-)0.9-1.1 (-1.3) × (0.6-)0.7-0.9(-1) mm, coarsely reticulate with 25-50(-60) areolae on each side.
2
n
= 32.
Flowering Feb-Sep. Flowing streams, ditches, lake margins, swamps, marshes, seeps; 0-3000 m; introduced; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que.; Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Europe; Asia; n Africa; introduced also elsewhere in the New World, tropical and s Africa, Australia.
