Stream orchid a hardy California native
Published 4:00 am, Sunday, May 23, 2010
You don't often use the terms "orchid" and "California native" to describe the same plant, but in fact both these descriptions apply to the Orchidaceae family member known as giant stream orchid, Epipactis gigantea. This charming rhizomatous, terrestrial, herbaceous orchid (whew, that's a mouthful) can be found in locations throughout Central and Northern California, including subalpine forests, foothill woodlands, in chaparral and valley grasslands and of course in wetlands.
Reaching up to 2 feet in height, this orchid produces ovate or lance-shaped, heavily veined green leaves that can reach 8 inches long starting in midspring, followed shortly by terminal spikes of as many as a dozen inch-long flowers. The three upper sepals are a greenish-yellow color, while the two upper petals are tipped in pink. The larger lower lip (labellum) is markedly veined a striking coppery red, with the lowest part of the lip a contrasting gold.
The showiness of epipactis' blooms belies the plant's toughness. It will grow, and gradually spread, in a spectrum of soils and light conditions, though it prefers humus-rich, moist soil in morning or filtered sun. My specimen established itself in clay soils, has handled dry spells in summer and fall and has returned reliably each spring. Martin Fletcher of California Gardens in Ojai (Ventura County) reports seeing this orchid growing on a clump of soil in the middle of a stream in full sun as well as in deep shade on a seep.
Stream orchid is an excellent choice for a pondside bed, as an understory planting in a filtered sun area, or in a woodland garden that gets regular water. For a richer color, consider using E. 'Serpentine Night,' whose foliage emerges a rich maroon color, aging to a bronzy green in summer.
Did you know?
Epipactis gigantea is also called giant helleborine. The lower lip and tongue move when the flower is touched or shaken, leading to the alternate name chatterbox orchid. Epipactis gigantea is pollinated primarily by syrphid flies, but wasps are also regular pollinators. The plant attaches a pollinium to the back of the pollinator and the latter then unloads it in the welcoming grasp of another specimen.
Grow in moist, fertile soil in morning or filtered sun, full sun on the coast. Given sufficient water, the plant's rhizomes will gradually spread to colonize a small area. Watering only during the spring bloom season will contain its growth. Zones 4-8.
Pests & diseases
Slugs and snails may go after tender young foliage, but generally epipactis is a tough terrestrial orchid.
You can find epipactis varieties beginning in March at California Flora nursery in Fulton; Ploughshares Nursery in Alameda; Mostly Natives nursery in Tomales; and Yerba Buena Nursery in Woodside. You can find it online at laspilitas.com.