Rorippa sessiliflora

(Nuttall) Hitchcock

Key Spring Fl. Manhattan, 18. 1894.

IllustratedEndemic
Basionym: Nasturtium sessiliflorum Nuttall in J. Torrey and A. Gray, Fl. N. Amer. 1: 73. 1838
Synonyms: Nasturtium limosum Nuttall Radicula limosa (Nuttall) Greene Radicula sessiliflora (Nuttall) Greene
Treatment appears in FNA Volume 7. Treatment on page 503. Mentioned on page 495.

Annuals; glabrous throughout. Stems (simple or several-branched from base) erect, branched distally, (0.9–)2–4.5(–6.3) dm. Basal leaves not rosulate; blade margins dentate. Cauline leaves shortly petiolate or sessile; blade oblong or oblanceolate to obovate, 1.5–7(–13.3) cm × (5–)10–28(–50) mm, (lateral lobes much smaller than terminal), base auriculate or not, margins dentate or less frequently sinuate, or (lateral lobes) denticulate or entire. Racemes considerably elongated. Fruiting pedicels divaricate-ascending to horizontal, straight, 0.5–2(–4) mm, (slender or stout). Flowers: sepals ascending to spreading, ovate, 1.2–2 × 0.5–0.8 mm; petals absent; median filaments 1–1.6 mm; anthers ovate, 0.2–0.3 mm. Fruits siliques, straight or curved, oblong to oblong-linear, (4–)6–9(–12) × (1.4–)1.8–2.8(–3.5) mm; ovules 158–242 per ovary; style 0.1–0.5 mm. Seeds biseriate, yellow-brown, cordiform, 0.4–0.5 mm, foveolate. 2n = 16.


Phenology: Flowering Mar–Oct.
Habitat: Mud flats, ditches, wet old fields, roadsides, sloughs, fallow fields, floodplains, stream banks, edges of pools, waste grounds, gardens
Elevation: 0-300 m

Distribution

V7 785-distribution-map.gif

Ala., Ark., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Mass., Miss., Mo., Nebr., N.C., Ohio, Okla., S.C., S.Dak., Tenn., Tex., Va., Wis.

Discussion

Both R. L. Stuckey (1972) and R. C. Rollins (1993) indicated that Rorippa sessiliflora has strongly saccate sepals, but all specimens that I examined failed to show any sign of this character. The species is very distinctive and can easily be distinguished by an absence of petals and by having fruiting pedicels 0.5–2(–4) mm.

Selected References

None.

Lower Taxa

None.
... more about "Rorippa sessiliflora"
Ihsan A. Al-Shehbaz +
(Nuttall) Hitchcock +
Nasturtium sessiliflorum +
Ala. +, Ark. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Mass. +, Miss. +, Mo. +, Nebr. +, N.C. +, Ohio +, Okla. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Va. +  and Wis. +
0-300 m +
Mud flats, ditches, wet old fields, roadsides, sloughs, fallow fields, floodplains, stream banks, edges of pools, waste grounds, gardens +
Flowering Mar–Oct. +
Key Spring Fl. Manhattan, +
Illustrated +  and Endemic +
Nasturtium limosum +, Radicula limosa +  and Radicula sessiliflora +
Rorippa sessiliflora +
species +