Called annual or perennial by different authorities.
3 to 4 feet.
Flowers white, August to November.
A very pretty border plant, seldom grown. In
growth it somewhat resembles the Willow Herb;
it has reddish stems (rather apt to fall about
unless supported), smooth narrow leaves, and a
long spike of white flowers with a drooping tuft
of anthers, looking very much like butterflies.
The seeds may be sown in the open border in early
April; the seedlings must be thinned out to a
foot apart and kept clear of weeds. The flowers
should appear in August, and will continue until
hard frost. In an unfavourable season the bloom
may be very late in appearing, and sometimes the
buds may not open at all. The plant may stand
a moderate winter, but it is best to raise it
annually from seed.