E-Flora BC: Electronic Atlas of the Flora of British Columbia

Juncus nodosus L.
tuberous rush (knotted rush)
Juncaceae (Rush family)

Introduction to Vascular Plants

© Adolf Ceska  Email the photographer   (Photo ID #5678)

E-Flora BC Static Map
Distribution of Juncus nodosus
Click here to view the full interactive map and legend
Details about map content are available here
Click on the map dots to view record details.

Species Information

Click on the image below to view an expanded illustration for this species.

Perennial herb from elongated rhizomes, the rhizomes with swollen nodes; stems arising singly, erect, 20-40 cm tall.
Located along the length of the stem, nearly circular in cross-section, tapered, the early leaves stiff, with prominent complete cross-walls; sheaths open, with minute, pointed, ear-shaped lobes.
Inflorescence terminal, 3-5 cm long, with (1) 3- to 15-flowered, globe-shaped heads, the heads less than 1 cm wide when pressed, the branches erect; perianth segments greenish-brown to tawny, 3-4 mm long, pointed, the inner about the same length as the outer; stamens 6; anthers 0.6-0.7 mm long, shorter than the filaments; involucral bract longer than inflorescence.
Capsules, narrowly three-angled, cone-shaped, pointed, uniformly tapered into short tips, longer than the perianth segments; seeds barrel-like, about 0.4 mm long, lacking tail-like appendages.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall
Source:  The USDA

Habitat / Range

Lakeshores and marshes in the lowland, steppe and montane zones; infrequent throughout BC, mostly E of the Coast-Cascade Mountains; N to AK, YT and NT, E to NF, and S to MA, PA, VA, IN, CO, UT, NV and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Juncus nodosus

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 765 996 1212
Slope Gradient (%) 0 0 0
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
6 7 8
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: IDF(3), MS(1), SBS(1)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References