3. Calystegia sepium (L.) R. Br. (hedge bindweed, wild morning glory, Rutland beauty)

Convolvulus sepium L.

Convolvulus sepium var. repens (L.) A. Gray

Convolvulus sepium L. f. malacophyllus Fernald

Convolvulus sepium f. coloratus Lange

Pl. 363 b, c; Map 1579

Stems mostly 50–300 cm long, scrambling or trailing, twining, at least toward the tip, glabrous or nearly so (hairy elsewhere). Leaves long-petiolate, glabrous or nearly so, the petiole more than (usually much more than) 1/2 as long as the midvein of the accompanying leaf blade. Leaf blades 2–9(–15) cm long, narrowly ovate-triangular to oblong-ovate or triangular, narrowed to a bluntly or more commonly sharply pointed tip, deeply cordate at the base, the sinus U-shaped or less commonly V-shaped, the basal lobes often each with 1 or 2 additional shallow lobes along the upper portion, frequently somewhat spreading, angular, bluntly to sharply pointed. Flowers solitary or less commonly paired in the axils of leaves, positioned mostly above the stem midpoint. Bracts 14–25(–32) mm long, usually overlapping only toward the base, not strongly inflated (usually appearing somewhat angular), ovate to triangular-ovate, bluntly to more commonly sharply pointed at the tip, glabrous or sparsely hairy along the margins. Sepals 11–15 mm long, elliptic to narrowly ovate. Corollas not doubled, 4–7 cm long, white or rarely pink. Fruits 10–15 mm long. Seeds 4–5 mm long. 2n=22. May–September.

Scattered, mostly north and west of the Ozark Division (North America, Europe, Asia; in North America, nearly throughout the U.S., the southern half of Canada, and northern Mexico). Borders of bottomland and mesic upland forests, banks of streams and rivers, margins of ponds, lakes, and sloughs, and disturbed portions of upland prairies; also fallow fields, crop fields, pastures, fencerows, gardens, railroads, roadsides, and open, disturbed areas.

According to Brummitt (1980), one name used by Steyermark (1963) and some other authors, Convolvulus sepium var. repens (L.) A. Gray, is actually a synonym of the unrelated pantropical species, Ipomoea imperati (Vahl) Griseb. (cited by Brummitt under another synonym, I. stolonifera (Cirillo) J.F. Gmel. [La Valva and Sabato, 1983]). Brummitt (1965, 1980) treated Calystegia sepium as consisting of a complex series of about a dozen intergrading subspecies, but in the absence of a comprehensive taxonomic revision of the group, his concepts are merely summarized here and not treated fully. The ssp. sepium is native to the Old World and has somewhat smaller flowers than the New World taxa. Nearly all of the Missouri specimens are referable to ssp. angulata Brummitt, which occurs throughout the species’ range but is especially prominent in the western states and the Great Plains. It is characterized by usually white corollas, glabrous stems and leaves, and leaf blade base with the lobes relatively spreading and the sinus frequently broadly U-shaped. The few pink-flowered specimens collected in Missouri appear otherwise to be referable to ssp. angulata. Two other taxa that are present in the eastern United States should be searched for in Missouri. Both have flowers with usually pink or pinkish-tinged corollas. The ssp. americana (Sims) Brummitt was erroneously reported for Missouri by Yatskievych and Turner (1990) and has yet to be confirmed as occurring in the state. It differs in being sparsely to moderately hairy and having the leaf blade base with a V-shaped sinus. A single aberrant specimen from Ralls County is possibly referable to ssp. erratica Brummitt, a usually glabrous taxon with the bracts grading into and not sharply distinguished from the sepals, as well as the leaf blade base with a narrow sinus and often slightly overlapping lobes. The specimen from Ralls County is unusual in having bracts that are somewhat larger than is typical for the species.

For a discussion of hybridization with C. silvatica, see the treatment of that species.