Ammannia robusta

Heer & Regel

Index Seminum (Zürich), adn. 1. 1842.

Synonyms: Ammannia alcalina Blankinship A. coccinea subsp. robusta (Heer & Regel) Koehne
Treatment appears in FNA Volume 10.

Herbs annual, robust, 3–10 dm. Stems: proximal branches often decumbent, length often equaling main-stem, unbranched, or branched near base. Leaf-blades usually lanceolate-linear, rarely spatulate, 15–80 × 4–15 mm. Inflorescences simple cymes, 1–3 (–5) -flowered mid-stem; peduncle stout, 0–0.5 mm. Pedicels 0. Floral-tube campanulate to urceolate, 3–5 mm; epicalyx segments as long as sepals; sepals 4 (–8); petals 4 (–8), pale lavender, sometimes with rose-purple midvein or rose-purple basal spot, 2–3 × 2.5–3.3 mm; stamens 4 (–8); anthers light yellow; style slender, well-exserted, 2 mm; stigma capitate. Capsules 4–6 mm diam., equal to or surpassing sepals, splitting irregularly. 2n = 34.


Phenology: Flowering late spring–late fall.
Habitat: Freshwater marshes, margins of pools and lakes, drying mud and sand flats, ditches, rice fields.
Elevation: 0–2100 m.

Distribution

B.C., Ont., Ariz., Ark., Calif., Colo., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Mich., Minn., Mo., Mont., Nebr., Nev., N.Dak., Ohio, Okla., Oreg., S.Dak., Tenn., Tex., Utah, Wash., Wyo., Mexico, West Indies, Central America, South America, Pacific Islands (Guam)

Discussion

Ammannia robusta flowers spring through fall in the northern part of the range and year-round southward. The species has spread worldwide as a result of introduction through rice cultivation.

Ammannia robusta is documented for New Jersey by a collection from the mid 1800s (P. Knieskern s.n., NY); there is no evidence that it became established in the state.

Selected References

None.

Lower Taxa

None.
... more about "Ammannia robusta"
light yellow +
dehiscent +  and introrse +
Shirley A. Graham +
Heer & Regel +
auriculate +  and cordate +
brochidodromous +
spatulate +, elliptic +, lanceolate +, linear-oblong +, oblong +, linear-lanceolate +  and linear +
membranous +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
complanate +
persistent +
obconic +, cylindrical +, urceolate +, turbinate +  and campanulate +
B.C. +, Ont. +, Ariz. +, Ark. +, Calif. +, Colo. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Mich. +, Minn. +, Mo. +, Mont. +, Nebr. +, Nev. +, N.Dak. +, Ohio +, Okla. +, Oreg. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Wash. +, Wyo. +, Mexico +, West Indies +, Central America +, South America +  and Pacific Islands (Guam) +
indehiscent +, septifragal +, septicidal +, loculicidal +  and dehiscence +
2-4-horned +
0–2100 m. +
campanulate +  and urceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
actinomorphic +, pedicellate +, subsessile +  and sessile +
trichomelike +
Freshwater marshes, margins of pools and lakes, drying mud and sand flats, ditches, rice fields. +
amphibious +  and terrestrial +
compound +  and simple +
1.5 cm15 mm <br />0.015 m <br /> (8 cm80 mm <br />0.08 m <br />) +
spatulate +  and lanceolate-linear +
deciduous +
submerged +  and emergent +
branched +  and unbranched +
branched +  and unbranched +
1-3(-5)-flowered +
distinct +
1 +  and 1400 +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
pinnately-veined +
pale lavender +
distinct +
2mm +  and 3mm +
obovate +  and suborbiculate +
0.25 cm2.5 mm <br />0.0025 m <br /> (?) +  and 0.33 cm3.3 mm <br />0.0033 m <br /> (?) +
Flowering late spring–late fall. +
Index Seminum (Zürich), adn. +
not +  and winged +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (?) +  and 0.04 cm0.4 mm <br />4.0e-4 m <br /> (?) +
3 +  and 250 +
concave-convex +, obovoid +  and semiglobose +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (?) +  and 0.05 cm0.5 mm <br />5.0e-4 m <br /> (?) +
alternating +
persistent +
subulate +  and deltate +
unbranched +  and branched +
anthocyanic +
creeping +  and decumbent +
submerged +
trailing +  and erect +
not throughout +  and glaucous +
4-angled +
punctiform +  and capitate +
petiolate +, subsessile +  and sessile +
well-exserted +
slender +
2 cm20 mm <br />0.02 m <br /> (?) +
not +  and clonal +
aquatic +, amphibious +  and terrestrial +
Ammannia alcalina +  and A. coccinea subsp. robusta +
Ammannia robusta +
Ammannia +
species +
aerenchymatous +
circumscissile +  and indehiscent +
indurated +, leathery +  and dry +
1 +  and 2 +