This section is from the book "The Florists' Manual", by William Scott. Also available from Amazon: The Florist's Manual.
These are known almost entirely under the name of achyranthes, but iresine is correct. They, with the coleus, are the principal plants used to furnish color to the tropical and foliage beds.
Their culture is so well known and so simple that little need be said. They thrive in any ordinary good soil. They have an advantage over the coleus in that they are not nearly so tender and will grow during winter when the coleus would starve. Outside, though injured by the first frost, they will not drop their leaves when the thermometer gets down to 40 degrees, as do many coleuses.
We grow them not only as bedding plants, but for our vases and veranda-boxes they are most useful, and do not monopolize the whole space to the sacrifice of other plants, as do the stronger growing coleuses.
Greenfly attacks them if smoking is neglected, and mealy bugs like them, but they can be thoroughly cleaned off when you start a new batch of cuttings.
Nothing can possibly root better than iresine at all times of the year. We select a few cuttings from outside that are clean and healthy in September, and from a few dozen of each kind a large lot-can be produced by bedding time. A hotbed grows them thriftily and quickly and gives you a chance to harden them off. To grow fast for cuttings they should have a temperature of 60 degrees, but will thrive finely in 10 degrees less.
I. Herbstii is the useful sort we know as Verschaffeltii; finely colored, habit spreading and free.
I. Herbstii aurea reticulata is the variegated form.
I. Lindeni is more erect; narrow leaves, deep rich color; a fine bedding plant.
There is also another variety, or I believe a species (the correct name I cannot find) with smaller, rounded leaf, of a fine bottle green color; in contrast with a lighter foliage plant this is the best of all.