This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
A pretty North American perennial, 6-18 in. high, with dense tufts of four-angled stems, ovate Gentian-like leaves, and trusses of tubular flowers of a deep red or crimson outside and yellow within. It is easily grown in a moist peaty soil in cool places, and may be increased by careful division in spring.