Elatine californica |
Elatine ambigua |
|
---|---|---|
California waterwort |
Asian waterwort |
|
Habit | Herbs, submersed or growing on exposed but wet substrates, 1–5 cm. | Herbs, submersed, 1.5–4(–8) cm. |
Stems | decumbent to erect, branched. |
prostrate or erect, branched. |
Leaves | light green to green, sometimes becoming reddish in terrestrial plants; stipules lanceolate, 0.5–0.6 mm, margins dentate, apex acute; petiole 1–4 mm; blade obovate to oblanceolate, 4–12(–15) × 1.2–3 mm, base narrowly cuneate, apex acute to obtuse. |
green; stipules lanceolate, 1 mm, margins dentate, apex acute; petiole 0.1–1 mm; blade lanceolate or oblong-elliptic, 2–6 × 0.5–1.5 mm, base cuneate, apex obtuse to acute. |
Pedicels | 1.5–2.5(–3.5) mm, recurved in fruit. |
0.5–2.5 mm, recurved in fruit. |
Flowers | sepals 4, usually equal, sometimes 1 reduced, oblong-ovate or widely lanceolate, 0.5–0.6 × 0.3–0.4 mm; petals 4, greenish white, slightly reddish, or pink, elliptic or ovate, 1–1.5 × 0.5–0.6 mm; stamens 8; styles 4. |
sepals 3, equal, oblong-ovate or broadly lanceolate, 0.5 × 0.3 mm; petals 0 or 3, reddish, long-elliptic or ovate, 1–1.5 × 0.5 mm; stamens 3; styles 3. |
Capsules | depressed-ovoid, 4-locular, 1.3–2.5 mm diam. |
oblong-ovoid, 3-locular, 1 mm diam. |
Seeds | 2–5 per locule, oblong to ellipsoid, curved 90–180°, 0.6–1 × 0.2 mm; pits elliptic, length 1–3 times width, in 6–10 rows, (16–)20–29 per row. |
10 per locule, narrowly oblong, straight or curved 15–30°, 0.3 × 0.1 mm; pits obscure, round, length 1–4 times width, in 6 rows, 19–25(–30) per row. |
Elatine californica |
Elatine ambigua |
|
Phenology | Flowering summer. | Flowering late spring–summer. |
Habitat | Pools, pond shores, rice fields, stream banks. | Pools, marshy places, rice fields. |
Elevation | 0–1900(–2600) m. (0–6200(–8500) ft.) | 0–100 m. (0–300 ft.) |
Distribution |
AZ; CA; ID; MT; NM; NV; OR; UT; WA; Mexico (Baja California)
|
CA; CT; MA; SC; VA; s Asia; se Asia [Introduced in North America; introduced also in Europe, s Pacific Islands, Australia] |
Discussion | Elatine californica is distinguished from other species of the genus by having long pedicels that are recurved in fruit and strongly curved seeds that can be nearly circular. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Elatine ambigua is a popular aquarium plant usually misidentified as E. trianda. It is also a common weed in rice fields. This species probably was introduced to California, South Carolina, and Virginia through rice farming. Its introduction to Connecticut and Massachusetts probably was through aquarium disposal or fish stocking. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 350. | FNA vol. 12, p. 352. |
Parent taxa | Elatinaceae > Elatine | Elatinaceae > Elatine |
Sibling taxa | ||
Synonyms | E. californica var. williamsii, E. williamsii | |
Name authority | A. Gray: Proc. Amer. Acad. Arts 13: 361, 364. (1878) | Wight: Bot. Misc. 2: 103, suppl. plate 5. (1830) |
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