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

Juncus tenuis Willd.
slender rush (poverty rush)
Juncaceae (Rush family)

Introduction to Vascular Plants

© Adolf Ceska  Email the photographer   (Photo ID #25354)

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Distribution of Juncus tenuis
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Species Information

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Perennial, loosely tufted herb from fibrous roots; stems erect, 15-75 cm long.
Located on the lower 1/3 of the stem, narrow (0.5-1.5 mm wide), flattened, lacking cross-walls; sheaths open, up to 6 mm long, longer than wide, thin, translucent, pointed, ear-shaped lobes.
Inflorescence terminal, 5-15 cm long, with few to numerous flowers, the flowers each with 2 involucral bractlets, the bracts ascending and longer than the inflorescence; perianth segments green, 3-4.5 mm long, pointed, the inner about the same length as the outer; stamens 6; anthers 0.6-0.8 mm long, shorter than the filaments.
Capsules, broadly cylindrical, rounded, 1-celled, about the same length as the perianth segments; seeds ellipsoid, about 0.4-0.6 mm long, lacking tail-like appendages.
This species complex was treated as a single, variable species in Ceska (1994) but in this manual I have segregated Juncus confusus, J. dudleyi, and J. interior as separate species.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Late Spring
Fruit/Seed characteristics:
Colour: Brown
Present over the Summer
Source:  The USDA

Habitat / Range

Dry to moist meadows, pastures, roadsides and ditches, mostly on disturbed soil in the lowland, steppe and montane zones; common in BC south of 55degreeN, infrequent in N BC; N to AK, YT and NT, E to NF and S to ME, MA, PA, NC, FL, MS, TX, NM, AZ and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Juncus tenuis

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) 706 1109 1680
Slope Gradient (%) 0 7 23
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
14 81 208
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
4 5 7
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: CDF(1), CWH(6), ESSF(3), MS(1), SBS(3)


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.

Synonyms and Alternate Names

Juncus dichotomus var. platyphyllus Wiegand
Juncus macer Gray
Juncus platyphyllus (Wiegand) Fernald
Juncus tenuis var. congestus Engelm.
Juncus tenuis var. multicornis E. Mey.
Juncus tenuis var. platyphyllus (Wiegand) F.J. Herm.
Juncus tenuis var. tenuis
Juncus tenuis var. williamsii Fernald

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References