1. Nicandra physalodes (L.) Gaertn. (apple of Peru, shoo-fly plant)

Pl. 562 d, e; Map 2617

Plants annuals, taprooted, unarmed. Stems 20–120 cm long, erect or ascending, unbranched or with few to several, ascending to spreading branches toward the tip, glabrous. Leaves moderately to long-petiolate, the petioles winged toward the tip or occasionally most of their length. Leaf blades 5–25 cm long, ovate to broadly ovate, simple, with shallow, broad, sometimes irregular, pinnate lobes, tapered to a sharply pointed tip, tapered at the base, the margins usually also with broad, sharp teeth, glabrous or nearly so at maturity, sometimes sparsely and minutely hairy when young. Inflorescences axillary or lateral, of solitary flowers. Flowers nodding, the flower stalk 0.8–1.5 cm, becoming only slightly elongated (to 1.2–2.0 cm) at fruiting. Calyces 1–2 cm long (in total length) at flowering, lobed to at or below the midpoint (excluding the 5 prominent, angular, basal auricles), sometimes nearly to the base, broadly tubular but strongly 5-angled at flowering, deeply concave at the base and with 5 angular to arrowhead-shaped, basal auricles (1 per lobe), persistent at fruiting, the tube becoming enlarged, papery, balloonlike, and with a strong network of raised veins, loosely enclosing the fruit (this usually easily visible when viewed from the tip), strongly 5-angled, green to tan. Corollas 1.5–3.0 cm long, broadly bell-shaped to occasionally nearly saucer-shaped, shallowly 5-lobed (the margin sometimes appearing merely scalloped), appearing pleated in bud, blue to light blue, usually with a lighter throat, this sometimes with 5 bluish markings (rarely entirely white elsewhere). Stamens with the filaments mostly somewhat longer than the anthers, hairy toward the base, the anthers erect, not fused laterally, dehiscent longitudinally, white to pale yellow, not exserted. Ovary 3–5-locular, the stigma usually positioned at about the same height as the anthers. Fruits berries, 1–2 cm long, mealy (not juicy), globose, 3–5-locular, green to greenish brown, with numerous seeds, lacking stony granules (these present elsewhere). Seeds 1.5–1.8 mm in longest dimension, more or less kidney-shaped to asymmetrically ovate or nearly circular, flattened, the surface with a fine network of ridges and pits, more or less shiny, orangish brown, lacking wings. 2n=20. July–September.

Introduced, scattered, sporadic (native of South America; introduced sporadically nearly throughout North America). Crop fields, old homesites, farmyards, railroads, and open, disturbed areas.

Steyermark (1963) noted that historically this species was grown to eradicate house flies. Stems were pulped and moistened with a small amount of milk to attract flies, which purportedly succumbed to lethal intoxication within a half hour after ingesting the mixture.