Nasturtium microphyllum

Plants glabrous throughout or sparsely pubescent. Stems (1–)2–10(–18) dm. Cauline leaves: petiole not winged, base auriculate; blade (3–)5–9(–11)-foliolate, (1.5–)2.5–10(–15) cm; lateral leaflets sessile or petiolulate, rachis not winged, blade smaller than terminal; terminal leaflet (or simple blade) suborbicular or oblong, (0.6–)1.5–3.5(–4.5) cm × (4–)8–20(–25) mm, base obtuse, cuneate, or subcordate, margins entire or repand, apex obtuse. Fruiting pedicels divaricate or descending, straight or, occasionally, recurved, (7–)9–21(–25) mm. Flowers: sepals 2.5–4 × 1–1.5 mm; petals white or pink, spatulate or obovate, 4.5–6 × 1.5–3 mm, (base to 1 mm), apex rounded; filaments 2.5–3.5 mm; anthers 0.7–1 mm. Fruits 1.4–2.2(–2.7) cm × 1–1.5(–1.8) mm; ovules 30–38(–40) per ovary; style 0.5–1.5(–2) mm. Seeds uniseriate, reddish brown, ovoid, (0.8–)1–1.2 × (0.6–)0.7–0.8(–0.9) mm, moderately reticulate with (75–)100–150(–175) areolae on each side. 2n = 64.

Phenology: Flowering Jan–Aug.
Habitat: Lake margins, streams, ponds, springs, river shores, seeps, swales, wet meadows
Elevation: 0-1500 m

Introduced; B.C., Man., N.B., Nfld. and Labr. (Nfld.), Ont., P.E.I., Que., Conn., Idaho, Ind., Ky., Maine, Mass., Mich., N.H., N.Mex., N.Y., Oreg., Pa., R.I., Vt., Wyo., Europe, introduced also elsewhere in the New World, Australia.

Discussion

Selected References

None.

Lower Taxa