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.
(Corylus and opsis, likeness; in foliage resembling the hazel). Hamamelidaceae. Woody plants, grown chiefly for their yellow fragrant flowers appearing in early spring and for the handsome foliage.
Deciduous shrubs, rarely trees: leaves alternate, strongly veined, dentate: flowers in nodding racemes with large bracts at the base, appearing before the leaves, yellow; calyx-lobes short; petals clawed, 5; stamens 5, alternating with entire or 2-3-parted short staminodes; styles 2; ovary half-superior, rarely entirely superior: fruit a 2-celled, dehiscent, 2-beaked caps., with 2 shining black seeds. - About 12 species in E. Asia and Himalayas.
These are low ornamental shrubs, with slender branches and pale bluish green distinct foliage; all are very attractive in early spring, when covered with numerous nodding spikes of yellow, fragrant flowers. Not hardy north of New York, except in sheltered positions. They grow best in peaty and sandy soil. Propagated by seeds sown in spring, best with slight bottom heat, and by cuttings of half-ripened wood in summer under glass; also by layers, rooting readily in moderately moist, peaty soil.
a. Flowers in many-fid. racemes.
B. Petals obovate to oblong-obovate.
c. Young branchlets and leaves beneath pubescent, at least on the veins.
Sieb. & Zucc. Shrub, to 4 ft.: leaves oblique and rounded or cordate at the base, roundish ovate or obovate, sinuate-dentate, glaucous beneath and pubescent, 2-3 in. long: racemes 7-10-flowered, 1-2 in. long, their bracts ovate; flowers bright yellow; stamens slightly longer than the obovate petals; calyx hairy. Japan. S.Z. 19. B.M. 5458. F.S. 20:2135. R.H. 1869, p. 230; 1878, p. 198; 1907, p. 403. G.C. II. 15:510; III. 25:210. Gn. 33, p. 441. S.I.F. 2:26. - This species has larger and handsomer foliage and flowers of a deeper yellow, in longer racemes, but C. pauciflora flowers more profusely and is somewhat hardier.
Hemsl. Shrub, 6-15 ft.: leaves obovate to oblong-obovate, abruptly acuminate, obliquely subcordate or cordate at the base, sinuate-denticulate, pubescent at least on the veins and grayish green beneath, 2-4 in. long: racemes about 2 in. long, their bracts nearly orbicular; petals orbicular-obovate, slightly longer than style and stamens; calyx hairy. Cent. China. G.C. III. 39:18. variety glandulifera, Rehd. & Wilson (C. glandulifera, Hemsl.). Young branchlets and petioles with scattered glandular bristles: calyx glabrous. H.I. 29:2819.
cc. Young branchlets glabrous; leaves glabrous or only with a few silky hairs on the veins beneath when young.
Veitchiana, Bean. Shrub, 3-6 ft.: leaves short-petioled, elliptic, abruptly acuminate, subcordate at the base, sinuate-denticulate, glaucous beneath, 3-4 in. long: racemes 1-2 in. long; petals obovate, slightly shorter than the stamens; calyx hairy; nectaries 2-parted. Cent. China. B.M. 8349. Gn. 76, p. 184.
bb. Petals with the blade as broad as or broader than long.
Willmottiae, Rehd. & Wilson. Shrub, to 12 ft.: leaves oval to obovate, cordate or truncate at the base, sinuate-denticulate, glaucescent beneath, 1-3 1/2 in. long: racemes 2-3 in. long; petals suborbicular; calyx glabrous; nectaries 2-parted, slightly shorter than the sepals. Cent. China. G.M. 55:191 (as C. multiflora).
Rehd. & Wilson. Shrub, 3-8 ft.: young branchlets with scattered glandular bristles: leaves on glandular petioles, ovate or broadly ovate, cordate or subcordate at base, sinuate-denticulate, on both sides sparingly silky-hairy when young, soon glabrous 2-4 in. long: racemes 1-2 in. long; petals hatchet-shaped, 1/6in. broad; nectaries emarginate at the apex; stamens and styles much shorter than petals; calyx glabrous. Cent. China. variety levis, Rehd. & Wilson. Branchlets and petioles without any glands. W. China. - Less showy than most other species.
aa. Flowers in 2-3-flowered racemes.
Sieb. & Zucc. Low, much-branched shrub, 2-3 ft.: leaves obliquely cordate, ovate, sinuate-dentate, ciliate, pubescent and glaucous beneath, 1-2 in. long: racemes 2-3-flowered, 1/2 - 3/4in. long; flowers light yellow; petals obovate, about as long as stamens and style. Japan. S.Z. 20. G.F. 5:342. Gt. 48:1467. B.M. 7736. G.W. 15, p. 101. J.H. III. 48:381. S.I.F2:26.
C. Griffithii, Hemsl. (C. himalayana, Hook., not Griff.). Shrub or small tree, to 20 ft.: young branchlets and leaves beneath densely pubescent: leaves subcordate: racemes 1-2 1/2 in. long; stamens and styles much shorter than the obovate petals. Himalayas. B.M.
6779. Alfred Rehder.