Field Bindweed (Convolvulus arvensis) is a more delicate, and much rarer, wild morning glory than its ubiquitous cousin Hedge Bindweed (Calystegia sepium, formerly Convolvulus sepium). Note the small arrowhead-shaped leaves. These were blooming in St. Michael’s Cemetery on the South Side Slopes.
Gray describes the genus and the species, which he places in the Strophocaulos group within the genus:
CONVOLVULUS [Tourn.] L. BINDWEED
Corolla funnel-form to campanulate. Stamens included. Capsule globose,
2-celled, or imperfectly 4-celled by spurious partitions between the 2
seeds, or by abortion 1-celled, mostly 2-4-valved. Herbs or somewhat
shrubby plants, twining, erect, or prostrate. (Name from convolvere,
to entwine.)
STROPHOCAÚLOS G.Don. Stigmas filiform; no bracts at or near the base of the calyx.
C. arvensis L. (Field B.) Perennial; stem procumbent or twining, and low; leaves ovate-oblong, arrow- or halberd-shaped, with the lobes at the base acute; peduncles mostly 1-flowered; bracts minute, remote; corolla 1.6-2 cm. long, white or tinged with red. — Old fields and in waste places. June-Aug. (Nat. from Eu.) Var. obtusifolius Choisy. Basal lobes of the leaves rounded. — Less common. (Adv. from Eu.)