Description:

• Soft, subsucculent, glabrous herbs; stems ± translucent, rarely woody at base; usually in damp, shady places
• Leaves opposite or alternate, rarely whorled or radical, simple, entire or variously toothed, usually petiolate; stipules 0
• Flowers bisexual, very irregular, resupinate, attractive, 1-many, on axillary peduncles, sometimes paniculate, sometimes peduncles clustered
• Sepals 3(-5), free, imbricate, 2 laterals flat, usually green, the lowermost petaloid, usually coloured, produced into a hollow spur or sac
• Petals 5, usually ± connate, anterior one largest, laterals 2-lobed
• Stamens 5; filaments free and linear below, broadened above and connate; anthers 2-thecous, large, elliptic, cohering to form a cap over ovary
• Ovary superior, 5-locular, with few to many ovules in each locule on axile placentas; style absent; stigma simple, sessile, 5-toothed or -lobed
• Fruit an explosively dehiscent loculicidal capsule, opening elastically into 5 twisted valves from placentiferous axis
• Seeds smooth or tubercled, glabrous or hairy; embryo straight; endosperm 0
• x = 7, 8, 10 (3, 5, 6, 9, 13) (polyploidy, B-chromosomes)

Nomenclature:

• Impatiens L.
  • Linnaeus: 937 (1753)
  • Sonder: 312 (1860)
  • Launert: 162 (1963)
  • Grey-Wilson: 1 (1980)

Distribution & Notes:

• Global: Species ± 850, mainly northern hemisphere, tropical Africa, tropical Asia to North America
• Southern Africa: Species 4 in moist eastern parts