Rubus parviflorus



The Basics

Kingdom - Plantae (plants). Subkingdom - Tracheobionta (vascular plants). Superdivision - Spermatophyta (seed plants). Division - Magnoliophyta (flowering plants). Class - Magnoliopsida (dicotyledons). Subclass - Rosidae. Order - Rosales. Family - Rosaceae (rose). Genus - Rubus L. (blackberry). Species - Rubus parviflorus Nutt. (thimbleberry).

Ecology: Thimbleberry grows as an erect, multibranched, leafy deciduous shrub that may reach 3 m tall. Size and distinguishing characteristics relating to leaves, glands, and pubescence can be highly variable. Thimbleberry stems and leaves are thornless. Stems range from 2 to 15 mm in diameter and are typically biennial. In west-central British Columbia, the majority of stems lived 2 years but some lived 3 years and produced large lateral branches. Thimbleberry produces alternate, simple, maple-shaped leaves with 3- to 7-pointed lobes. Leaves generally measure up to 20 cm long and wide and have irregularly serrate margins. Thimbleberry often forms clumps or dense thickets through an "extensive network" of rhizomes. On 1-year-old clearcuts in Oregon's Coast Ranges, thimbleberry shrubs had rhizomes that averaged 201 cm long and 14.4 buds per 1 m of rhizome length.


Western thimble-berry is an erect, unarmed, shrub, 1 1/2-5 ft. tall with gray, flaking bark; strong, flexible stems; large, shiny, maple-like, deciduous leaves; terminal clusters of white (sometimes pink-tinged) flowers; and red, raspberry-like fruit. Erect, unarmed shrub with palmately lobed leaves and raspberrylike fruits.

The fruits are important seasonal food for numerous birds and mammals, including bears, and are a welcome, if not inspired, trailside snack. Wild Red Raspberry has much smaller flowers, prickles on stem, and compound leaves with 3 or 5 leaflets, Black Raspberry has recurved thorns, small white flowers whose sepals are longer than the petals, compound leaves, and black fruits.


Fire effects: Most fires only top-kill thimbleberry shrubs. Mortality is likely restricted to sites where high temperatures penetrate deep into the mineral soil layer. Thimbleberry sprouts from surviving rhizomes and often emerges from soil-stored seed on burned sites. Recovery following fire is generally rapid.. Generally, thimbleberry reaches or exceeds prefire abundance soon after fire through postfire sprouting and seedling establishment. Seedlings emerged "immediately" after fire in British Columbia's subboreal spruce zone.


Flowering and Fruiting - Thimbleberry flowers are perfect but self-incompatible...Thimbleberry seeds are dispersed by birds and mammals.

Seed Banking - Thimbleberry seed is likely long-lived in the soil seed bank; viable, buried seed is often found on sites with little or no thimbleberry cover..Thimbleberry seeds are generally found in the litter, duff, and mineral soil layers; abundance of seed is often less in the lower mineral soil layers than in the upper soil, duff, and litter layers.

Germination - Seeds germinate best after cold stratification, and mineral soil is a better germination substrate than duff or litter. Plant propagation studies conducted in British Columbia found that thimbleberry seeds soaked in water for 24 hours and chilled at 2 deg C for 4 to 5 months germinated best.

Vegetative Regeneration - Thimbleberry is strongly rhizomatous. Rhizome growth is important to increasing the size and density of thimbleberry clones as well as regeneration of shrubs following top-kill or movement of rhizome fragments. Thimbleberry clones may live up to 45 years. Postfire sprouting from rhizomes also occurs.

Species Distribution


USDA Plant Database
USDA, NRCS. 2016. The PLANTS Database (, 4 February 2016). National Plant Data Team, Greensboro, NC 27401-4901 USA.

Flora of North America
Flora of North America Editorial Committee, eds.  1993+.  Flora of North America North of Mexico.  19+ vols.  New York and Oxford.

Intermountain Herbarium
Consortium of Intermountain Herbaria. 2016. http// Accessed on February 04.

Burke Museum Plant Image Collection
The plant image collection at the Burke Museum, University of Washington.

Jepson Manual
The Jepson Manual: Vascular Plants of California. B.G. Baldwin, D.H. Goldman, D.J. Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken [editors]. 2012. 2nd edition, thoroughly revised and expanded. University of California Press, Berkeley, CA. $131.95, hardcover; 1600 pages. ISBN-13: 978-0520253124.