"Bi" Latin for "twice", and "torta", "twisted", refer to the contorted rhizome roots in some species. 

Subalpine, alpine. Meadows, wetlands. Summer.
Winter Trail Head, June 27, 2000.

This white-topped buckwheat is abundant in high mountain and alpine areas, sometimes being so thick that it gives a snowy appearance to meadows.  The soft cottony flower head often has a blush of pink, but as delicate and appealing looking as the flowers are, do not be fooled; their scent is most often quite unpleasant:  One common name for the plant is "Miner's Toes"!  Partially red stems and leaves are characteristic, and the reds become more pronounced in the fall.  Typical plants are twelve to eighteen inches tall but it is common to find plants two feet tall.

Frederick Pursh named this species Polygonum bistortoides in his 1814 Flora Americae Septentrionalis; John Kunkel Small (1869-1938) renamed it Bistorta bistortoides in 1906.  (More biographical information.)

Subalpine, alpine. Meadows, wetlands. Summer.
Pass Creek Trail, July 19, 2007.

Leaves have distinctive venation and a sheath encloses the stem below each bulging leaf node.

Subalpine, alpine. Meadows, openings, tundra. Summer.
Sharkstooth Trail, July 30, 2004.

This is a miniature of the much taller, more conspicuous, and more abundant Bistorta bistortoides.  It grows in scattered colonies in open, grassy areas.  Its very unusual structure makes it well worth bending for. "Vivipara" is Latin for "brings forth alive",  and a viviparous plant asexually produces plants genetically identical to itself as sprouts on itself.  In the case of Bistorta vivipara, green/black/red bulblets are produced below the tiny flowers.  These fall to the ground and can grow into mature plants.    The more common Bistorta bistortoides is not viviparous.  Human beings are viviparous in the zoological sense: we give birth to live young.  (See also Lithophragma glabrum.)

Linnaeus named this plant Polygonum viviparum in 1753 and Delarbre renamed it Bistorta vivipara in 1800.

Subalpine, alpine. Meadows, openings, tundra. Summer.
American Basin, July 24, 2007.

Young bulblets show below the flowers in the bottom right corner of the photograph.