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Afghanistan to Central China: Afghanistan, China North-Central, China South-Central, East Himalaya, Kazakhstan, Kirgizstan, Nepal, Pakistan, Qinghai, Tadzhikistan, Tibet, West Himalaya as per POWO;
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Common name: Himalayan Rush
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Flora of Uttarakhand- Grass4 for Id- JM : 5 posts by 4 authors.
Wild Grass captured on 13/8/10 during the trek from Ghangaria (around 11,000 ft.) to Hemkunt Sahib (around 14000 ft.).


this may a member of Cyperaceae


I think Juncus prismatocarpus (Juncaceae)


Juncus prismatocarpus


Thanks, …
A link of Juncus prismatocarpus from FOP:

http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=240001374
But it not mentioned in Concise Flowers of Himalayas by Oleg Polunin & Adam Stainton.
There is another species (Juncus himalensis) which looks similar & mentioned in Concise Flowers of Himalayas by Oleg Polunin & Adam Stainton. See the illustration & details:


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