Rubus ulmifolius
Elmleaf blackberry
(c) Joan Simon, some rights reserved (CC BY-SA) · licence
Family: Rosaceae · Type: Subshrub · Not Native
Rubus ulmifolius (Elmleaf blackberry) is a non-native California subshrub in the Rosaceae family, recognized by hairy waxy stems and massive flower clusters.
Elmleaf blackberry is a naturalized shrub found in disturbed areas, growing to 3 meters tall with arching stems that can root at their tips. Flowering from late spring to summer, this plant produces white to pink flowers 10 to 15 millimeters long in clusters of 10 to 60 blooms. Growing with 5-angled stems 5 to 10 millimeters in diameter that are densely short-hairy and glaucous, it persists for two years with a distinctive growth habit. Its compound leaves typically have 5 leaflets, with terminal leaflets oblong to narrow-obovate, evenly double-toothed, and densely white-hairy on the undersides. The plant produces a blackberry-type fruit that ripens to a deep black color.
Identification and appearance
Key characters: Co-occurs with 12 species; distinguished by hairy waxy stems and massive flower clusters
How to tell it apart
vs Toxicodendron: Rubus has palmate leaves with 3-5 leaflets spreading from one point; poison oak has 3 leaflets arranged along a stem.; vs Ribes: Rubus stems are thorny or bristly canes; currants/gooseberries are unarmed or have sharp spines at nodes only.; vs Rosa: Rubus leaves are palmate (fingers from palm); rose leaves are pinnate (leaflets along a central stem).; vs Acer: Rubus has compound leaves with separate leaflets; maple leaves are single lobed blades.; vs Fragaria: Rubus grows as tall, arching canes; strawberries form low runners with flower stalks rising from base.
Frequently asked questions
Is Rubus ulmifolius native to California?
No. Rubus ulmifolius is not native to California (recorded as not native).
What plant family does Rubus ulmifolius belong to?
Rubus ulmifolius is in the Rosaceae family, genus Rubus.
Related species
Other California species in the same genus, family, or bioregion.
- Rubus ulmifolius var. anoplothyrsus — Elm leaf bramble
- Rubus ulmifolius var. ulmifolius — Elmleaf blackberry
- Rubus ursinus — California blackberry
- Rubus armeniacus — Himalayan blackberry
- Rubus glaucifolius — Waxleaf raspberry
- Rubus glaucifolius var. ganderi — Cuyamaca raspberry
- Sanguisorba officinalis — Great burnet
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.