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.
(Kerkis, ancient Greek name). Leguminbsas. Judas Tree. Red-Bud. Trees or shrubs grown for their pink flowers profusely produced early in spring before the leaves; very interesting, also, in mode of branching, as seen in mature trees.
Leaves deciduous, alternate, petioled, palmately nerved, entire: flowers papilionaceous, pedicelled, pink or red, appearing before or with the leaves, in clusters or racemes from the old wood; calyx 5-toothed, red; petals nearly equal, the uppermost somewhat smaller: pod compressed, narrow-oblong, narrow-winged on the ventral suture, many-seeded. - Seven species in N. Amer., and from S. Eu. to Japan.
These trees and shrubs are very ornamental, with handsome distinct foliage and abundant showy flowers in spring, very effective by their deep pink color. They are well adapted for shrubberies or as single specimens on the lawn, and attain rarely more than 20 or 30 feet in height, forming a broad, irregular head when older. Only C. canadensis is hardy North, while C. chinensis can still be grown in sheltered positions near Boston, but is occasionally injured in severe winters; the others can not be grown successfully farther north than New York. They grow best in rich sandy and somewhat moist loam, and should be transplanted when young, as older plants can hardly be moved with success. Young plants, four or five years old, produce flowers freely and may be recommended for forcing, especially C. chinensis and C. racemosa, which are the most beautiful of all. Propagated by seeds, sown in spring, best with gentle bottom heat; sometimes increased by layers, or by greenwood cuttings from forced plants in early spring; C. chinensis grows also from greenwood cuttings in summer under glass.
b. Flowers in clusters: leaves usually pubescent only beneath near the base.
Linn. Fig. 882. Tree, to 40 ft.: leaves roundish or broadly ovate, usually cordate, 3-5 in. long: flowers rosy pink, 1/2in. long, 4-8 in clusters: pod 2 1/2-3 1/2 in. long. From N. J. south, west to Mo. and Texas. S.S. 3:133-4. A.F. 13:1370. Gng. 6:290. F.E. 9:593. Mn. 2, p. 139. M.D.G. 1899:434-5 (habit). Gn. 25, p. 347. - A very desirable ornamental tree for the northern states. variety alba, Rehd. Flowers white. variety plena, Schneid. Flowers double. - Recently C. canadensis has been split by Greene into several new species (see Fedde, Rep. Spec. Nov. Veget. 11:110).
Fig. 882. Cercis canadensis. (X 1/2)
Bunge (C.japonica, Sieb.). Fig. 883. Tree, to 50 ft., shrub in cultivation: leaves deeply cordate, roundish, with a white, transparent line at the margin, subcoria-ceous, glabrous, shining above, 3-5 in. long: flowers 5-8, purplish pink, 3/4in. long: pod 3-5 in. long, narrow. China, Japan. F.S. 8:849. Mn. 2:139. G.F. 6:476. - A very beautiful species, with the flowers nearly as large as those of C. Siliquastrum and more abundant.
Fig. 883. Cercis chinensis. (Natural size) bb. Leaves usually cuneate-obovate, smaller.
bb. Flowers in pendulous racemes.
Oliv. Tree, to 30 ft.: leaves broadly ovate, truncate or subcordate at the base, pubescent beneath, 2 1/2-4 in. long: flowers rosy pink, about 1/2in. long on slender pedicels of about equal length, in many-flowered racemes 1 1/2-3 in. long: pod 2 1/2- 4 in. long. Cent. China. H.I. 1894. - The handsomest of all. Young plants have not proved hardy at the Arnold Arboretum, but it is perfectly hardy in S. England.
aa. Leaves rounded or emarginate at the apex, usually broader than long. occidentals, Torr. (C calif ornica, Torr.). Shrub, to 15 ft.: leaves cordate, roundish, glabrous, about 2 in. wide: flowers rose-colored, 1/2in. long: pod 2-2 1/2 in. long. Calif. Torrey in U. S. Explor. Exped. 1838-1842, 17, pl. 3-A closely allied species is C. reniformis, Engelm. (C. texensis, Sarg.). Small tree: leaves sub-coriaceous, 3-5 in. wide, sometimes pubescent beneath: pod 2-4 in. long. Texas, New Mex. S.S. 3:135.
Siliquastrum, Linn. Tree, to 40 ft.: leaves roundish, deeply cordate, glabrous, 3-5 in. wide: flowers 3-6, purplish rose, 3/4in. long: pod 3-4 in. long. S.Eu., W.Asia. B.M. 1138. Gn. 25, pp. 346, 347, 350; 33, p. 416; 42:342, p. 343; 44, p. 379; 52, p. 5. G.C. III. 52:6 (habit). G. 25:209. R.H. 1899:469 (abnormal form). variety alba, Carr. (variety albida, Schneid.) with white flowers