Browallia americana
Sp. Pl. 2: 631. 1753.
Stems 0.3–150 cm, glabrous or viscid-pubescent, hairs usually fine, simple. Leaves: petiole 0–5 cm; blade ovate to cordate. Pedicels 0–15 mm. Flowers: calyx length 1/4–1/2 times corolla tube, glabrous or viscid-pubescent; corolla blue or violet with white or yellow center or entirely white, without hairs enclosing mouth, 1–12 cm, limb spreading. Seeds prismatic, to 1 mm, reticulate-foveolate. 2n = 22.
Phenology: Flowering Jun–Aug.
Habitat: Disturbed sites.
Elevation: 0–1000 m.
Distribution
Introduced; Conn., Fla., Ga., La., Mass., Miss., Central America, South America, introduced also in Mexico, Asia, Africa, Indian Ocean Islands, Pacific Islands, Australia.
Discussion
Browallia americana is highly variable. It may be an ephemeral annual or a shrub. Native to the Andes of northwestern South America, and perhaps Central America, it has been introduced in tropical and subtropical areas around the world. The variable vegetative morphology in Peru and Ecuador has challenged taxonomists and resulted in over 30 synonyms (J. F. Macbride 1962; A. H. Gentry 1993; D. J. Mabberley 2008).
In the flora area, Browallia americana sometimes escapes from cultivation. The cultivated plants do not retain the variability found where they are native, and only blue-, violet-, and white-flowered forms are in the nursery trade.
Selected References
None.