- Kingdom - Plantae – Plants
- Subkingdom - Tracheobionta – Vascular plants
- Superdivision - Spermatophyta – Seed plants
- Division - Magnoliophyta – Flowering plants
- Class - Magnoliopsida – Dicotyledons
- Subclass - Caryophyllidae
- Order - Caryophyllales
- Family - Caryophyllaceae – Pink family
- Genus - Silene L. – catchfly
- Species - Silene scouleri Hook. – simple campion
General: Erect perennial herb from a simple to branched crown, the stems several, up to 8 dm. tall, densely pubescent throughout and glandular above.
Leaves: Leaves opposite, numerous, the basal slender-petiolate, the blades oblanceolate, up to 15 cm. long and 3 cm. wide; cauline leaves 2-8 pairs, reduced gradually upward, becoming sessile above.
Flowers: Flowers numerous, the inflorescence narrow and elongate, consisting of a series of small, congested, lateral cymes; calyx broadly tubular, 5-lobed, 10-18 mm. long; corolla greenish-white to purplish, the claw of the petal 7-16 mm. long, the blade flaring, 4-8 mm. long, from bi-lobed to nearly equally 4-lobed, with 2 appendages at the base, 1-3 mm. long; ovary with a stalk 3-6 mm. long, puberulent to woolly; stamens 10; styles 3.
Fruits: Capsule 1-celled.