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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
from FNA
AZ; CA; ID; MT; NM; NV; OR; UT; WA; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; CT; MA; SC; VA; s Asia; se Asia [Introduced in North America; introduced also in Europe, s Pacific Islands, Australia]
[BONAP county map]
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
E. ambigua, E. americana, E. brachysperma, E. chilensis, E. heterandra, E. minima, E. ojibwayensis, E. rubella, E. triandra
E. americana, E. brachysperma, E. californica, E. chilensis, E. heterandra, E. minima, E. ojibwayensis, E. rubella, E. triandra
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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