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 fine fleshy - rooted Chinese perennial about 2 ft., with coarsely toothed leaflets and trusses of tubular rosy-carmine flowers spotted with brown and yellow in the throat. I. grandiflora is a somewhat similar plant, quite as vigorous, and with much deeper coloured rose-purple flowers. Both kinds are sold to lovers of choice hardy flowers, and realize good prices, but the trade is limited. They flourish in any good garden soil in warm sunny spots, and may be raised from seeds sown under glass, and by division of the rootstocks in early autumn. I. Koopmanni, mauve pink; I. Olgoe, rose purple; I. lutea, yellow; and I. variabilis, rose purple, are other species.
Fig. 210. - Incarvillea Delavayi.