What plant is that?

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Photo credits: © Francis R. Underwood 2015

This month’s mystery plant is a small perennial plant with white flowers and a glabrous stem.  It has alternate, entire leaves and it is a root parasite.  It grows from 5 to 15” tall.  It is often found in large colonies in fields or sometimes on ledges. The flowers are composed of 4 to 5 white sepals sometimes referred to as “tepals”.  The fruit is an oddly- shaped drupe with a short neck at the top.  This plant blooms from late May through early July.

It’s. . .