Juncus arcticus Willd.
arctic rush
Juncaceae (Rush family)
Introduction to Vascular Plants
arctic rush
Juncaceae (Rush family)
Introduction to Vascular Plants
SUBTAXA PRESENT IN BC
Juncus arcticus ssp. alaskanus
Species Information
General:
Perennial herb from long, creeping rhizomes; stems arising singly, not in dense clusters, round, usually straight, smooth, wiry, erect, 15-60 cm tall.
Leaves:
Reduced to small sheaths at the base of the stem; sheaths shiny brown.
Flowers:
Inflorescence dense, with 3 to 12 dark-coloured flowers; branches 1-7 cm long, appearing as if on the side of the stem, located above the middle, in the upper third of the stem; perianth segments dark with translucent margins, red-brown, 4-5 mm long, the outer slightly longer than the inner ones, pointed, the inner segments blunt; stamens 6; anthers shorter than the filaments; involucral bract 2-20 cm long, cylindrical, resembling a continuation of the stem.
Fruits:
Capsules, with blunt tips, about equal to the perianth segments; seeds spindle-shaped, 0.8-1.1 mm long, lacking tail-like appendages.
Notes:
The taxonomic relationship between this species and related J. balticus has not been clarified. Juncus arcticus is a variable species, with many infraspecific taxa described. The whole complex requires further study and more intensive collecting throughout our area. I am treating all of our plants as ssp. sitchensis with the exception of some plants from northern BC which belong to the rare ssp. alaskanus.
1. Involucral bract 10-20 cm long; inner perianth segments pointed, narrowly translucent-margined................ssp. sitchensis Engelm.
1. Involucral bract 2-5 cm long; inner perianth segments with short awns, broadly translucent-margined................. ssp. alaskanus Hult.
Ecology
Ecological Framework for Juncus arcticus
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)
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 |
||
|
Avg |
Min |
Max |
|
| Elevation
(metres) |
1001 | 0 | 2011 |
| Slope
Gradient (%) |
7 | 0 | 45 |
|
Aspect (degrees) |
227 | 10 | 359 |
| Soil
Moisture Regime (SMR) [0 - very xeric; 4 - mesic; 8 - hydric] |
5 | 1 | 8 |
| Modal
Nutrient Regime
Class |
D | ||
| #
of field plots species was recorded in: |
80 | ||
| Modal
BEC Zone Class |
ESSF | ||
|
All BEC Zones (# of stations/zone) species was recorded in |
BG(6), BWBS(4), CWH(16), ESSF(18), IDF(17), PP(6) | ||
|
Source:
Klinkenberg 2013
|
|||
Habitat and Range
Tidal flats and lakeshores in the lowland and montane zones; ssp. alaskanus - rare in N and E BC; ssp. sitchensis - common in coastal BC; ssp. alaskanus - N to AK, YT and NT; ssp. sitchensis - amphiberingian, N to AK, E Asia.Status Information
Synonyms
Synonyms and Alternate Names:
Juncus arcticus var. alaskanus (Hultén) S.L. Welsh
Juncus balticus var. alaskanus (Hultén) A.E. Porsild