- Name also: Night-flowering Silene
- Family: Pink Family – Caryophyllaceae
- Growing form: Annual or biennial herb.
- Height: 25–40 cm (10–16 in.). Stem unbranched–sparsely branched, densely rough-hairy base, upper part glandular-haired, sticky.
- Flower: Corolla regular (actinomorphic)–slightly zygomorphic, creamy white–yellowish red, approx. 2–2.5 cm (0.8–1 in.) wide; petals 5, deeply 2-lobed. Corolla mouth with lobed corona (an additional small corolla). Calyx fused, quite narrow (expanding as seed ripens), 5-lobed, 10–veined, glandular-haired. Stamens 10. Gynoecium syncarpous, with 5 styles. Flowers solitary or a sparsely flowered cyme. Flowers open in the evening and are fragrant at night.
- Leaves: Opposite, lowest stalked, upper stalkless. Blade elliptic–ovate, with entire margin, hairy, light green.
- Fruit: Egg-shaped, yellowish brown, 14–20 mm (0.55–0.8 in.) long capsule splitting into 6 lobes, teeth recurved.
- Habitat: Gardens, cultivated land, wasteland, railway yards.
- Flowering time: July–September.
Night-flowering catchfly is an old companion of humans in most of Europe. The species has arrived in Finland as a seed, mixed in with imported garden and crop seed, in ballast soil, soldiers’ provisions and via the railway. Night-flowering catchfly is however still quite rare and is only established to any extent in a small number of places. This short-lived species is usually able to ripen at least some of its seed in the Finnish climate, but it will only occasionally grow in the same place the following summer. It is more typical that this wandering plant is found once and then disappears without a trace.
The best places to find night-flowering catchfly is around allotments, compost heaps, soil heaps and similar places. Its greyish, sticky and therefore often grubby stem is however not so easy to notice. The plant does not even draw much attention to itself through its flowers as it keeps them closed during the day with the petals rolled inwards. As night falls however it bursts open and releases a wonderful fragrance which attracts potential pollinators in the dark – night butterflies arrive in large groups to suck the nectar and pollinate the plants. Many other catchflies have similar nocturnal flowers. Of its close relatives, it can often be told apart from white campion (S. latifolia) on the basis of the colour of its flowers: white campion’s corolla is pure white, while night-flowering catchfly’s usually has shades of yellowish red. Unclear classification can usually be resolved by touch: white cockle’s upper stem is not sticky.