This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
(named by Thunberg in honor of his friend and patron, Johann van der Deutz). Saxifragaceae. Very ornamental shrubs grown for their showy white or blush flowers appearing in spring or early summer.
Upright: leaves deciduous, rarely persistent, opposite, petioled, serrate, usually with rough stellate pubescence: flowers in panicles, rarely in racemes or in corymbs, white, sometimes purplish, epigynous; calyx-teeth 5; petals 5; stamens 10, rarely more, shorter than the petals; filaments usually winged and toothed at the apex; styles 3-5, distinct:' caps. 3-5-celled, with numerous minute seeds. - About 50 species in E. Asia and Himalayas and 1 in Mex. Monograph by Schneider in M.D. 1904:172-188, and a hort. monograph by Lemoine in J.H.F. 1902:298-314; see also Rehder in Sargent, Plant. Wilson. 1:14-24 for Chinese species.
The deutzias belong to our most beautiful and most popular ornamental shrubs; they are very floriferous and of easy cultivation. D. parviflora and D. grandi-flora are the hardiest, and also D. gracilis, D. Sieboldi-ana and D. scabra are hardy as far north as Massachusetts; the recently introduced D. longifolia, D. Schneid-eriana, D. discolor, and D. Wilsonii have proved fairly hardy with slight protection or in sheltered positions at the Arnold Arboretum. One of the most tender is D. purpurascens. Of the hybrids, D. Lemoinei is the hardiest, while D. rosea has proved about as hardy as D. gracilis; D. kalmiaefiora, D. myriantha and others are tenderer. Most of the deutzias have white flowers, but D. rosea, D. purpurascens, D. longifolia, D. myriantha, D. kalmiseflora and some varieties of D. scabra, have the flowers carmine outside or pinkish. They flower most profusely if pruned as little as possible, although an occasional thinning out of the old wood soon after flowering will be of advantage.
The deutzias thrive in almost any well-drained soil, and are well adapted for borders of shrubberies. Potted plants forced with a temperature not exceeding 50° develop into beautiful specimens for the decoration of greenhouses and conservatories, especially D. Lemoinei, D. gracilis and D. discolor. The same plants cannot be forced again. Propagate readily by greenwood and hardwood cuttings, also by seeds sown in pans or boxes in spring.
Fig. 1245. Deutzia gracilis. (X 1/2) a. Petals valvate in the bud.
B. Flowers in panicles or racemes; calyx-teeth short (except in the hybrids).
c. Leaves glabrous below or nearly so.
Fig. 1245. Shrub, to 3 ft., with slender, often arching branches: leaves oblong-lanceolate, acuminate, sharply serrate, with sparse stellate hairs above, nearly glabrous beneath, bright green, 1-2 in. long: flowers pure white, in racemes; petals erect or somewhat spreading, oblong; stamens much shorter than the petals; calyx-teeth persistent. May, June. Japan. S.Z. 8. P.F.G. 2, p. 7. F.S. 6:611. R.H. 1891, p. 203. G.M. 50:563. Gn. 39, p. 200. G.W. 12, p. 534. Gt. 1897:384. H.F. 1:48. J.F. 1:44. V. 7:217. variety aurea, Schelle. Leaves yellow. variety albo-marmorata, Lemoine. Leaves sprinkled with white.
(D. gracilis x D. purpurascens. D. gracilis rosea and D. discolor rosea, Lemoine). Leaves ovate-oblong, acuminate, bright green, slightly paler below, very sparingly stellate-pubescent on both sides: flowers pink, campanulate, in panicles; calyx-lobes longer than the tube; filaments slightly toothed or subulate, but strongly toothed in all varieties except in variety venusta and variety multiflora. F.E. 30:423. G. 27:274. variety campanulata, Rehd. With large white campanulate flowers G. 28:485. variety venusta, Rehd. With white flowers G. 27:275. variety multifldra, Rehd.
With white flowers variety eximia, Rehd. With white flowers tinted pink outside, in upright panicles. variety carminea, Rehd. With light pink flowers tinted carmine outside. variety flori-bunda,Rehd. With white flowers tinted pink outside. J.H.F. 1902:312. variety grandiflora, Rehd. With flowers of the same color, but larger. All these varieties were originally described by Lemoine as varieties of D. gracilis except the two last ones, which he has under D. discolor.
cc. Leaves stellate-pubescent beneath.
d. Filaments all toothed at the apex.
E. Calyx-lobes shorter than the tube; petals upright.
Shrub, to 6 ft.: leaves all petioled, ovate to ovate - lanceolate, rounded at the base, crenate-dentate, with rough pubescence on both sides, dull green, 1-3 in. long: panicles erect, 2-4 in. long; flowers white or blushed, with erect petals; calyx-lobes deciduous. June, July. Japan, China. S.Z. 6. B.M. 3838. B.R. 1718. S.B.F.G. II. 4:393. Gn. 37, p. 315. F.E. 31:1163. H.U. 1, p. 106. variety angusti-fdlia, Voss. Branches reddish brown: leaves ovate-lanceolate, rougher. variety crenata, Voss (D. crenata, Sieb. & Zucc. D. dentata, Hort. D. mitis, Hort.). Branches brown: leaves ovate or oblong-ovate, less rough. This variety is less common in cult, than the former. variety marmo-rata, Rehd. (variety aureo-variegata, Schneid.). Leaves spotted with yellowish white. variety punctata, Arb. Kew (variety albo-punctdta, Schneid.). Leaves sprinkled with white dots. variety Fortunei, Schneid. Flowers larger. F.E. 31:1071. variety Watereri, Rehd. (variety punicea, Schneid. D. crenata Watereri, Lemoine). Flowers white, tinted carmine outside. G.C. III. 39:340. variety plena, Rehd. (D. crenata variety plena, Maxim.). Flowers double, white, tinged with rose outside.
R.H. 1867: 70. F.S. 17:1790; 18:1850. G.21:263. F. 1863:153. G.F. 8:112; here belongs also Pride of Rochester, with very large flowers, faintly tinged with rose outside. Gn. 33, p. 514. variety candidissima, Rehd. (D. scabra variety albo-plena, Schneid. D. crenata candidissima plena, Carr. D. Wellsii, Hort.). Flowers double, pure white.