Manyflower tobacco

Petunia acuminata Graham, Edinburgh New Philos. J. 5: 378. 1828; Nicotiana acuminata var. multiflora Reiche

Herbs, annual, robust, from loose basal rosette. Stems branched from base (proximal branches longer), 5–20 dm, viscid-pubescent. Rosette leaves: petiole length equaling blade; blade ovate or orbiculate, 6–12 cm, surfaces viscid-pubescent, somewhat scabrous adaxially. Cauline leaves: petiole length 1/3–1/6 blade; blade elliptic to lanceolate, becoming very narrow near inflorescence, 10–25 cm, apex acuminate, surfaces viscid-pubescent, somewhat scabrous adaxially. Inflorescences few-branched, somewhat leafy; flowering crepuscular. Pedicels 0.5–2 cm. Flowers: calyx strongly purple-veined, 1–2 cm, membranous, viscid-pubescent (hairs without swollen bases), lobes long-triangular, unequal, longest equaling tube; corolla straight, 2.5–10 cm (excluding limb), viscid-puberulent externally, tube white or white tinged with greenish purple, sometimes striped, 0.8–4 cm × 2–3 mm, widening to throat 1–4 × 5 mm, glabrous or minutely puberulent internally, limb spreading, white, circular, 2–4 cm diam., lobes shallow, deltate or emarginate; stamens inserted near base of throat, included; filaments unequal, in 2 equal or unequal pairs, 4 cm, 1 filament shorter than either pair, pubescent proximally; style straight, just surpassing longest stamen pair. Capsules broadly ovoid, 1–1.2 cm. Fruiting calyces tearing along membranous sinuses, covering ca. 1/2 of mature capsule. Seeds 0.9–1 mm. 2n = 24.

Flowering Dec–Jul. Open sandy or gravelly areas; 0–2000 m; introduced; Calif., Nev., Oreg., Wash.; South America (Chile); introduced also in Mexico (Baja California).

Nicotiana acuminata is native to Chile and is naturalized on the West Coast from Baja California to Washington. It is easy to confuse with the native N. attenuata but differs in its much longer corolla tube and usually emarginate limb. The flowers are often clustered near the tips of the few inflorescence branches. Plants from the western United States are often identi­fied as var. multiflora.