You selected Juncus compressus var. subtriflorus E.Mey. This is a synonym for:

Accepted scientific name:
Juncus drummondii E.Mey. (accepted name)
Synonyms:
Juncus arcticus var. gracilis Hook. (synonym) 1 literature reference for Juncus arcticus var. gracilis Hook.
Juncus compressus var. subtriflorus E.Mey. (synonym) 1 literature reference for Juncus compressus var. subtriflorus E.Mey.
Juncus drummondii forma davisonii H.St.John (synonym) 1 literature reference for Juncus drummondii forma davisonii H.St.John
Juncus drummondii var. humilis Engelm. (synonym) 1 literature reference for Juncus drummondii var. humilis Engelm.
Juncus drummondii var. longifructus H.St.John (synonym) 1 literature reference for Juncus drummondii var. longifructus H.St.John
Juncus drummondii var. subtriflorus (E.Mey.) C.L.Hitchc. (synonym) 1 literature reference for Juncus drummondii var. subtriflorus (E.Mey.) C.L.Hitchc.
Juncus pauperculus O.Schwarz (synonym) 1 literature reference for Juncus pauperculus O.Schwarz
Juncus subtriflorus (E.Mey.) Coville (synonym) 1 literature reference for Juncus subtriflorus (E.Mey.) Coville
Common names:
Common name Language Country
Drummond rush - USA Click here to show the literature
 reference
Drummond's rush - USA Click here to show the literature
 reference
Classification:
Plantae
Phylum Magnoliophyta
Class Liliopsida
Order Poales
Family Juncaceae
Genus Juncus
Distribution: Alaska, Subarctic America, Northern America; Alberta, Western Canada, Northern America; Aleutian Is., Subarctic America, Northern America; British Columbia, Western Canada, Northern America; California, Southwestern U.S.A., Northern America; Colorado, Northwestern U.S.A., Northern America; Idaho, Northwestern U.S.A., Northern America; Montana, Northwestern U.S.A., Northern America; Nevada, Southwestern U.S.A., Northern America; New Mexico, South-Central U.S.A., Northern America; Northwest Territories, Subarctic America, Northern America; Oregon, Northwestern U.S.A., Northern America; Utah, Southwestern U.S.A., Northern America; Washington, Northwestern U.S.A., Northern America; Wyoming, Northwestern U.S.A., Northern America; Yukon, Subarctic America, Northern America
Additional data: Western USA and Canada from New Mexico and Arizona to Alaska.
Source database: IOPI-GPC, 10.0, Aug 2007
Latest taxonomic scrutiny: Kirschner J., 2002
Online resource: http://www.bgbm.org/IOPI/GPC/PTaxonDetail.asp?RIDentifier=385
CoL taxon LSID: urn:lsid:catalogueoflife.org:taxon:e614c920-29c1-102b-9a4a-00304854f820:ac2010