Equisetum species- Chandragiri Hills, Kathmandu, Nepal

Are you sure second and third pics belong to Equisetum? To me looks like any flowering/fruiting bunch.. 

It was in the same area and thought to be from same plant. May be different. My carelessness.

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I suggest to examine the ridges on the sheaths (single or double) and look it up in Khullar’s book or any other descriptive literature.  Ferns of Nepal 1 (free from Godavary) even illustrated its close relative from up in N.W. Nepal. I expect you will presumably have read that fertile material is yet more distinctive, but you photographed young, sterile shoots.