Nigel P. Taylor and Daniela Zappi
Royal Botanic Gardens, Kew, UK.
Herbaceous, semi-succulent, erect, glabrous plants, never woody. Leaves generally petiolate, with two distal glands, venation pinnate, margin entire to variously crenate or dentate, leaf-blades fleshy when alive, drying membranaceous; stipules absent. Inflorescences of axillary small cymes or fascicles, or flowers solitary. Flowers hermaphrodite, with bilateral symmetry, hypogynous, calyx (3-)5-merous, lobes fused and forming a nectar-secreting spur, corolla 5-merous, lobes fused, showy, brightly coloured, white, pink, salmon, red or mauve; stamens 5, minute, filaments and anthers connate into a calyptra above gynoecium, anthers dehiscing longitudinally; ovary superior, 5-locular, with many ovules with axillary placentation. Fruit a fleshy capsule, opening by explosive longitudinal dehiscence with valves curling up, 10-20-seeded; seeds generally rounded, testa smooth, matt, brown, embryo straight, endosperm lacking or little.
Notes on delimitation
- Placed within the Ericales, together with Marcgraviaceae (APG II, 2003).
Distribution in the Neotropics
- Introduced into the Neotropics, represented by a single species, Impatiens walleriana Hook. f., very widespread in the Atlantic Forest of Brazil and known as 'Maria Sem Vergonha'. Other species cultivated as ornamentals.
Distinguishing characters (always present)
- Filaments and anthers fused over gynoecium forming a calyptra.
- Capsule explosively dehiscent with valves curling up.
Other important characters
Key differences from similar families
- Differs from Begoniaceae by hermaphrodite flowers and symmetric leaves.
- From many other herbaceous plants by the particular arrangement of its stamens over the gynoecium, which apparently avoids self-pollination.
Number of genera
- 1: Impatiens L.
Notable genera and distinguishing features
- A few species cultivated in gardens, I. walleriana naturalized in Eastern Brazil.
APG II, 2003. An update of the Angiosperm Phylogeny group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society 141(4): 399-436.
How to cite
Taylor, N. & Zappi, D. (2009). Neotropical Balsaminaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://www.kew.org/science/tropamerica/neotropikey/families/Balsaminaceae.htm.