Platanthera unalascensis
Alaska piperia, slender-spire orchid, slender-spire orchid, Slender-Spire Orchid
(c) Cayman Lanzone, some rights reserved (CC BY) · licence
Family: Orchidaceae · Type: Herb · Native
Platanthera unalascensis (Alaska piperia, slender-spire orchid) is a native California herb in the Orchidaceae family, recognized by broad lip with upcurved tip and short spurs, but features somewhat variable.
Alaska piperia, also known as slender-spire orchid, is a California native found throughout the California Floristic Province, excluding the Great Valley and South Coast Ranges, and the Modoc Plateau, growing in dry sites among scrub, woodland, and forest below 3,000 meters. Flowering from May to August, it produces green flowers with a broadly ovate to lance-elliptic, upcurved lip and a short spur pointed back or down.
Identification and appearance
Key characters: 11 sympatric species; broad lip with upcurved tip and short spurs, but features somewhat variable
Habitat and range
Habitat: Generally dry sites, scrub, woodland, forest
Elevation: < 3000 m
California counties: Humboldt, San Diego, Siskiyou, Mariposa, Tulare, Tuolumne, Trinity, Fresno, Shasta, San Bernardino, Marin, Plumas, Alpine, Calaveras, Santa Clara, Kern, Santa Barbara, Los Angeles, Madera, Orange, Sonoma, El Dorado, Mono, Modoc, Contra Costa, Mendocino, San Mateo, Butte, Sierra, Nevada, Santa Cruz, Tehama, Lassen, Glenn, Lake, Placer, Napa, Del Norte, Monterey, San Francisco
Outside California: to Alaska, northeastern Canada, South Dakota, New Mexico
Bloom period
Platanthera unalascensis blooms May--Aug.
How to tell it apart
vs Listera: Piperia flowers have obvious backward spurs; Listera flowers lack spurs entirely.; vs Platanthera: Piperia is leafless at flowering with dense spikes; Platanthera has leafy stems when blooming.; vs Epipactis: Piperia has tight cylindrical spikes of tiny spurred flowers; Epipactis has loose rows of larger spurless flowers.; vs Goodyera: Piperia is leafless when flowering; Goodyera has distinctive white-veined evergreen leaves present at bloom.; vs Spiranthes: Piperia flowers have backward spurs in straight spikes; Spiranthes lacks spurs and flowers spiral up stem.
Frequently asked questions
Is Platanthera unalascensis native to California?
Yes. Platanthera unalascensis is native to California (recorded as native).
When does Platanthera unalascensis bloom?
Platanthera unalascensis blooms May--Aug.
Where in California does Platanthera unalascensis grow?
Platanthera unalascensis occurs in Humboldt, San Diego, Siskiyou, Mariposa, Tulare, Tuolumne, Trinity, Fresno and other counties, at elevations of < 3000 m.
What plant family does Platanthera unalascensis belong to?
Platanthera unalascensis is in the Orchidaceae family, genus Platanthera.
What habitat does Platanthera unalascensis grow in?
Platanthera unalascensis grows in Generally dry sites, scrub, woodland, forest.
Related species
Other California species in the same genus, family, or bioregion.
- Platanthera yadonii — Yadon's rein-orchid
- Platanthera yosemitensis — Yosemite bog-orchid
- Platanthera colemanii — Coleman's rein-orchid
- Platanthera cooperi — Chaparral rein-orchid
- Platanthera dilatata var. leucostachys — White-flowered bog-orchid
- Platanthera elegans — Coast piperia
- Spiranthes perexilis — Slender starry ladies' tresses
- Spiranthes porrifolia — Western ladies' tresses
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.