Smilax jamesii
English peak greenbrier, English Peak Greenbrier
(c) Steve Matson, some rights reserved (CC BY), uploaded by Steve Matson · licence
Family: Smilacaceae · Type: Vine · Native
Conservation status: CNPS 4.2
Smilax jamesii (English peak greenbrier) is a native California vine in the Smilacaceae family, recognized by . Key differences: higher elevation, glaucous leaf undersides, longer erect inflorescences.
English peak greenbrier is a California native perennial vine found in the Klamath Ranges and Cascade Range in montane conifer forest near lakesides and streambanks at elevations of 1,500 to 2,500 meters. Flowering from May to July, this plant produces small spreading perianth parts in delicate clusters. Growing as a vine with long, zigzag rhizomes and herbaceous stems reaching 2 to 3 meters tall, it winds through forest understories with remarkable flexibility. Its distinctive leaves are 5 to 8 centimeters long, triangular to ovate, dark green on top and glaucous underneath, with a truncate to slightly heart-shaped base and acute or rigid tips. The vine produces dark blue fruits 6 to 8 millimeters long that dry to a dull maroon color.
Identification and appearance
Key characters: 1 sympatric species. Key differences: higher elevation, glaucous leaf undersides, longer erect inflorescences
Habitat and range
Habitat: Lakesides, streambanks, alder thickets in montane conifer forest
Elevation: generally 1500-2500 m
California counties: Siskiyou, Trinity, Del Norte, Shasta
Bloom period
Smilax jamesii blooms May-Jul.
Conservation status
CNPS 4.2
How to tell it apart
vs Lonicera: Smilax has tendrils and umbel flower clusters; Lonicera lacks tendrils and has tubular paired flowers.; vs Aristolochia: Smilax has 6-part regular flowers and tendrils; Aristolochia has irregular pipe-shaped flowers without tendrils.; vs Humulus: Smilax has tendrils and small 6-part flowers; Humulus lacks tendrils and has cone-like hop fruits.; vs Vitis: Smilax has multiple tendrils at leaf base with umbel clusters; Vitis has single tendrils opposite leaves with branched clusters.
Frequently asked questions
Is Smilax jamesii native to California?
Yes. Smilax jamesii is native to California (recorded as native).
When does Smilax jamesii bloom?
Smilax jamesii blooms May-Jul.
Where in California does Smilax jamesii grow?
Smilax jamesii occurs in Siskiyou, Trinity, Del Norte, Shasta, at elevations of generally 1500-2500 m.
What plant family does Smilax jamesii belong to?
Smilax jamesii is in the Smilacaceae family, genus Smilax.
Is Smilax jamesii rare or endangered?
Smilax jamesii carries California Rare Plant Rank 4.2, state rank S3S4.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.