5. Petunia Juss. (petunia)

Plants annual (perennial herbs elsewhere), unarmed. Stems erect to loosely ascending or ascending from a spreading base, with few to several ascending branches, moderately to densely pubescent with short, spreading, multicellular, glandular-hairs (the plants somewhat sticky to the touch). Leaves alternate, often appearing opposite near the stem tip, sessile or with short, mostly winged petioles. Leaf blades simple, oblanceolate to elliptic or ovate, unlobed, the margins entire, the surfaces moderately to densely pubescent with short, spreading, multicellular, glandular-hairs. Inflorescences axillary or lateral (the uppermost flowers sometimes appearing terminal), of solitary flowers. Flowers ascending and/or spreading, the fruits either ascending or nodding. Calyces 1.2–1.8 cm long, deeply 5-lobed (often nearly to the base), bell-shaped at flowering, rounded at the base, lacking basal auricles, the lobes usually slightly unequal, linear to narrowly oblong, rounded or bluntly pointed at the tips, glandular-hairy, persistent more or less intact at fruiting. Corollas 2.5–6.0 cm long (sometimes longer in cultivated plants), funnelform to trumpet-shaped, very shallowly 5-lobed, the lobes broadly rounded to broadly and bluntly pointed, appearing pleated toward the tip in bud (but not spirally twisted), variously colored. Stamens with filaments longer than the anthers, unequal in length, attached at or below the midpoint of the corolla tube, the anthers free, erect or incurved, not exserted, dehiscent longitudinally, light yellow. Ovary 2-carpellate the style elongate, positioned above the level of the uppermost anthers, green. Fruits capsules, dry, (7–)9–15 mm long, ovoid to narrowly ovoid, 2-locular, tan or light brown, dehiscent longitudinally from the tip, with numerous seeds, unarmed. Seeds 0.5–0.8 mm in longest dimension, more or less circular ro broadly elliptic, oval, or angular, flattened, the surface with a fine network of ridges, light to dark brown, lacking wings. About 40 species, South America.

Some botanists accept an expanded generic concept of Petunia that increases the number of included species to about 45 and expands the native range northward into the United States. The Missouri species are among those that are important in horticulture, generally as bedding plants grown for their bright flowers and long flowering period.