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

Introduction to Vascular Plants


© Adolf Ceska     (Photo ID #25354)


E-Flora BC Static Map

Distribution of Juncus tenuis
Click here to view the full interactive map and legend

Species Information

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.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

USDA Species Characteristics

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


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)
1109 706 1680
Slope Gradient (%)
7 0 23

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

81 14 208
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
5 4 7
Modal Nutrient Regime
# 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)

Habitat and 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.

SourceThe Illustrated Flora of British Columbia


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