Hydrolea uniflora
Autik. Bot., 34. 1840.
Herbs, erect or decumbent, to 6 dm, unbranched, with short reproductive branches or with branches arising from prostrate stems. Stems green to brown, glabrous or puberulent, without long, jointed hairs; thorns 1 or 2 per node, 6–15 × 0.5–1.2 mm. Leaf blades lanceolate, 3–10 × 1–2 cm, base attenuate to acute, margins entire or serrulate, surfaces glabrous. Inflorescences axillary, fasciculate, 1–10-flowered, or on short, leafy branches. Flowers: sepals broadly lanceolate to ovate, 5–8 × 1.5–4 mm, glabrous or puberulent, without glandular trichomes; corolla blue, occasionally white, petals 7–11 × 4–6 mm; ovary glabrous; styles 2, 3.5–5 mm, glabrous. Capsules globose, 4–6 mm wide, glabrous. Seeds ovoid, 0.5–0.6 × 0.2–0.3 mm. 2n = 20.
Phenology: Flowering Jun–Sep.
Habitat: Stream banks and pond margins.
Elevation: 0–300 m.
Distribution
Ala., Ark., Ill., Ky., La., Miss., Mo., Okla., Tenn., Tex.
Discussion
Hydrolea uniflora is very similar morphologically to H. quadrivalvis but differs from it in lacking long, jointed hairs and by having flower clusters borne on long (to 4 cm) peduncles.
Selected References
None.