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red-stem waterwort, Southwestern waterwort, three-flower waterwort

mosquito waterwort

Habit Herbs, emergent on wet substrates, 1–6(–16) cm. Herbs, emersed on wet substrates, 0.5–3 cm.
Stems

ascending or prostrate, branched.

ascending or prostrate, branched.

Leaves

reddish green;

stipules lanceolate, 0.5–0.6 mm, margins dentate, apex acute;

petiole 0.5–1(–3) mm;

blade oblong-lanceolate, 3–8 × (0.5–)1–2(–2.2) mm, base attenuate to rounded, apex obtuse to slightly emarginate.

usually green, sometimes reddish green;

stipules ovate-lanceolate, 1 mm, margins irregularly toothed, apex acute;

petiole 0.5–2 mm;

blade obovate to broadly elliptic-oblong, 2–4 × 0.5–1.5 mm, base usually cuneate, sometimes rounded, apex acute to obtuse, notched.

Pedicels

0–0.5 mm, erect.

absent.

Flowers

sepals (2–)3, if 2, equal, if 3, 1 smaller, oblong-ovate or widely lanceolate, 1–1.5 × 1–1.5 mm;

petals 3, pinkish white to reddish, elliptic or ovate, 1–1.5 × 0.5 mm;

stamens 3;

styles 3.

sepals 2(–3), if 2, equal, if 3, 1 smaller, oblong, 1.1–1.3 × 0.3 mm;

petals 3, pinkish, elliptic to ovate, 1–1.5 × 0.5 mm;

stamens 1–6 (number variable within plant);

styles 3.

Capsules

oblong-ovoid, 3-locular, 1.5–2.5 mm diam.

globose, 3-locular, 1.1–1.7 mm diam.

Seeds

10–20(–30) per locule, narrowly oblong, straight or curved to 15°, 0.5–0.7 × 0.1–0.3 mm;

pits angular-hexagonal, length 1–2 times width, in 8–10 rows, 16–25(–30) per row.

8–12 per locule, broadly ellipsoid to oblong, straight or curved 15–30°, 0.3–0.5 × 0.1–0.2 mm;

pits rounded-hexagonal, length 1–2 times width, in 9–10 rows, 12–18 per row.

Elatine rubella

Elatine heterandra

Phenology Flowering summer. Flowering summer.
Habitat Muddy shores, shallow vernal pools, ditches, rice fields. Wet mud of montane ponds.
Elevation 0–2900 m. (0–9500 ft.) (400–)1000–1500 m. ((1300–)3300–4900 ft.)
Distribution
from FNA
AZ; CA; CO; ID; KS; MT; NE; NM; NV; OR; SD; UT; WY
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[BONAP county map]
from FNA
CA; NM; TX
[BONAP county map]
Discussion

Reports of Elatine rubella from southern British Columbia and Washington are based on misidentifications of E. brachysperma and E. chilensis, respectively.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

In California, Elatine heterandra is known from the North Coast Ranges and the Sierra Nevada; additionally, two disjunct localities are known for the species in McKinley County, New Mexico, and Kenedy County, Texas.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 12, p. 352. FNA vol. 12, p. 353.
Parent taxa Elatinaceae > Elatine Elatinaceae > Elatine
Sibling taxa
E. ambigua, E. americana, E. brachysperma, E. californica, E. chilensis, E. heterandra, E. minima, E. ojibwayensis, E. triandra
E. ambigua, E. americana, E. brachysperma, E. californica, E. chilensis, E. minima, E. ojibwayensis, E. rubella, E. triandra
Name authority Rydberg: Mem. New York Bot. Gard. 1: 260. (1900) H. Mason: Madroño 13: 240. (1956)
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