Impatiens capensis, commonly called orange jewelweed or spotted touch-me-not, is a North American native wildflower; like most temperate Impatiens species it is annual.
Unlike the I. walleriana hybrids commonly grown in gardens, I. capensis grows about a metre tall and half as wide with an open, almost candelabra-like structure. The plant prefers moist, shady conditions, often alongside its close relative I. pallida, the pale touch-me-not, which has light yellow flowers and is otherwise very similar. It will grow in full shade but benefits from a bit of morning sun; it will also survive in sunnier locations if it receives enough moisture. As a woodland plant, it likes a light, humic soil, but it prefers clay over sand.
Flowering begins in midsummer and continues until early autumn. Because of the open growth habit and the slender stems, the flowers almost seem to hang in midair when viewed against surrounding greenery. In the shady areas these plants prefer, flowers stand out very well (thought to be one source of the common name jewelweed). The small flowers are orange and yellow with orange spots and bonnet-shaped; I personally find the shape more like something out of the movie Alien. The spur at the back of the flower is a nectary and the flowers are pollinated by bees and hummingbirds. Seed-set begins in August.
Seedlings unfortunately seem to be susceptible to damping-off, an invariably fatal fungal disease. This might be expected given the damp habitats the species prefers; on the other hand one might also expect it to be resistant to fungi exactly because it likes moist conditions. In any event, seedlings that survive into maturity are generally trouble-free and don’t even seem to be bothered by slugs. One issue is that, as mentioned, the stems are fairly slender and in the wild the plants are often supported by nearby growth; in the garden they have a tendency to fall over at the roots if they aren’t propped up.
As in all members of the genus, the ripe seedpods explode on contact, sending the seeds flying all over the place. This provides the source of both the generic name Impatiens (impatient) and touch-me-not.
Unfortunately, you’ll almost never find this species commercially available any more and few people cultivate them unless they have a wildflower garden. This is a shame because it introduces a valuable touch of colour into shady spots, and unlike the beleaguered standard I. walleriana garden bedding, it isn’t affected by the impatiens downy mildew that’s sweeping the continent (only that species and its derivatives are affected). As an interesting aside, the sap of this plant is held by some to be an effective antidote to poison ivy (Toxicodendron radicans) rash.
I have it growing next to Solomon’s seal (Polygonum biflorum) and wood poppies (Stylophorum diphyllum). I originally got the seeds from plants growing wild in a local park (please harvest noninvasive wild seeds ethically! – no more than 10% from any one plant) and now I’m trying to get it to spread to all the odd shady bits of the garden. Fortunately, unlike so many wildflowers, this species is not under threat or endangered.