In memory of Browning's cousin, James Silverthorne, the "Charles" of the
poem. The "one plant" of the last two stanzas is supposed to be the
_Spotted Persicaria_, "a common weed with purple stains upon its rather
large leaves." According to popular tradition this plant grew beneath
the Cross, and the stains were made by drops of blood from the Savior's
wounds. (Berdoe, _Browning Cyclopædia_, page 268, quoting from Rev. H.
Friend, _Flowers and Flower Lore_.)