18. Calystegia sepium (Linnaeus) R. Brown, Prodr. 483. 1810.
[F W]
Hedge bindweed
Convolvulus sepium Linnaeus, Sp. Pl. 1: 153. 1753
Perennials, rhizomatous. Herbage glabrate, glabrous, or hairy. Stems trailing or twining-climbing. Leaves: blade linear, ovate, broadly to narrowly triangular, or triangular-hastate, (24–)36–50(–150) mm, base usually lobed, sometimes nearly truncate, lobes usually 1- or 2-pointed, sometimes rounded, basal sinus usually acute to rounded, rarely almost closed. Bracts immediately subtending sepals, in subsp. erratica, intergrading with sepals, oblong, oval, or ovate, 12–34 × 5–26(–28) mm, proximally flat or keeled, not or scarcely saccate, margins not or scarcely enfolding sepals, apex acute to subobtuse or truncate. Flowers: sepals lanceolate, 10–19(–25) mm; corolla pink or white, (28–)30–70(–80) mm.
Subspecies 8 (6 in the flora): North America, South America, Europe, Asia, Africa.
Subspecies of Calystegia sepium mostly show strong geographic separation; morphologic intermediates between subspecies of C. sepium and between C. sepium and other species of Calystegia make taxonomy difficult. Subspecies roseata Brummitt is known from Atlantic coasts of Europe, temperate coasts of South America, Easter Island, New Zealand, and Australia; subsp. spectabilis Brummitt is known from Europe and Asia.
