Juncus acuminatus Michx.

Montana: Lincoln County: [locality and coordinates withheld; status in Montana: S1 (Critically Imperiled; MTNHP)],
Ca. 13 h, long narrow lake w/ one extensive (1 h) floating Sphagnum mat on the SE side which is surrounded on all sides by water. The open water is entirely littoral w/ scattered patches of floating Potamogeton natans and Nuphar variegatum being dominant. The mat is dominated in areas by Carex lasiocarpa, C. cusickii, C. rostrata, and Eriophorum gracile. Surrounding forest mixed w/ Pinus contorta, P. monticola, Larix occ., and Abies gr. Surface water relatively nutrient rich for a peatland: (all in mg/L) hardness 109.8, Ca 33.8, Mg 6.12, K 0.8. With Equisetum fluviatile, C. lenticularis, C. rostrata, Rhamnus alnifolia, and C. diandra. Abundance: common, caspitose on hummocky margins of the lake. Growing in shallow water to 10 cm deep. Phenology: Fruits.

R. Bursik 1109A, Jun 24, 1988
With C. Clemens
ID, Accession: 117084, Barcode: ID013580