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.
Biennial or perennial, setaceous-pilose: stem erect, simple, panicled above: leaves crenulate; root-leaves petioled, obovate, obtuse; stem - leaves lanceolate-acuminate: calyx hairy, the lobes long-acuminate, a third shorter than the corolla; calyx appendages like the lobes but half shorter and reflexed; flowers 25 or more, violet, with a longer and narrower tube than in C. alpina, and longer divisions of the limb. N. Asia, Caucasus, W. Eu. B.M. 659. R.H. 1861:431. - The type is rare, but variety eximia, Hort., is somewhat commoner: it is dwarfer, much branched, with long, scabrous leaves and pale bluish to violet flowers variety divergens, Willd., has larger flowers and broader leaves than the type. G.C. III. 16:597. C. sibirica usually does best when treated as a biennial.
AA. Calyx without appendages.
b. Flowers very wide-spreading, i.e., rotate, wheel-shaped, almost flat, c. Blossoms all erect.
Perennial, 4-6 in.: stems rigid, glabrous: leaves fleshy, sessile, gray-green, lanceolate, slightly serrate-dentate, the lower obtuse, the upper long-acuminate: calyx-lobes awl-shaped, spreading or recurved, one-fourth shorter than the corolla: flowers 5-9 in a corymbose raceme 1 1/4 in. long, 3/4in. wide, pale purplish blue; corolla rotate, almost starlike, with a dark spot in the throat; pistil large, white, twice the length of the corolla, with a yellow stigma. S. Austria. Gn. 8, p. 173. G. 18:81. G.W. 12, pp.446, 710. C. Tommasiniana, Hort., is an allied plant, with very wiry growth and pendent pale blue flowers C. Stdnsfieldii, Hort., is a supposed hybrid, perhaps between C. Waldsteiniana and C. car-patica.
Annual, 1 ft. or less, branching: lower leaves obovate and crenate; upper leaves narrow, entire: flowers violet with white base and blue intermediate parts, erect on long simple pedicels. Eu. B.M.2581.
Variety alba, Hort. Flowers white.
cc. Blossoms not all erect. d. Habit trailing or pendulous. 33. fragilis, Cyrill. Perennial, 4-6 in.: stem diffuse, trailing: root-leaves long-petioled, roundish - cordate, obtusely dentate, or cre-nately lobed; stem - leaves smaller, scattered, the uppermost ovate-lanceolate: flowers pale purplish blue with a white center, 1 1/2 in. wide, in loose corymbs; calyx - lobes linear- lanceolate, acuminate, erect, almost equaling the corolla; style exserted: caps', ovoid. Italy. B.M. 6504. P.M. 11:25. G.C. III. 43:378. Gn. 8, p. 174; 47. p. 278; 63, p. 53. G. 18:120. G.W. 2, p. 381. variety hirsuta, DC, is a hairier form. - This is the best species for hanging-baskets, window- and veranda-boxes, and for covering large stones in the rockery. Propogation by cuttings in spring, the roots being too fragile to divide well. Not so hardy as C. garganica.
Perennial, 3-6 in.: stem diffuse, with pendent branches: lower leaves reniform-cordate, crenate-dentate; upper leaves ovate-acute, dentate: raceme lax; peduncles 1-2-flowered; calyx-tube spheroid, the lobes spreading, a third or fourth shorter than the glabrous blue rotate corolla. Mt. Gargano in Italy, and elsewhere. B.R. 1768. Gn. 48, p. 295; 43, p. 25. G.M. 54:664. G.W. 4, p. 255. variety hirsuta, Hort., is a hairier form. Gn. 46, p. 253; 48, p. 297. - Half-shaded position. Prop, by cuttings or by division.
dd. Habit not trailing or pendulous.
Perennial, more or less pubescent, 5-6 in.: leaves cordate, coarsely and acutely dentate, lower rotund, others ovate-acute: raceme lax; calyx-tube spherical, the lobes spreading, linear-lanceolate, somewhat unequal, a half shorter than the rotate purplish corolla; style exserted. Piedmont. Gn. 60, p. 64. - Rare rock-plant for light, stony soil.
Perennial, 6-9 in.: stems somewhat erect: leaves all alike petiolate, cordate, roundish, acutely angular-dentate: calyx-tube spheroid, lobes erect, acuminate, a third shorter than the infundibuliform blue-purple corolla: flowers racemose. Dalmatia. - Allied to C. garganica, but the corolla not so deeply 5-cut. Gn. 61, p. 225; 72, p. 469. variety major, Hort. Flowers nearly twice larger than in the type, 1 1/2 in. across, making a large mound of purple-blue. G.C. III. 48:58. Gn. 60, p. 1ll; 63, p. 110. G.W. 3, p. 13.
Perennial, 2-3 in.: stems suberect, branching: branches 1-3-flowered: leaves subsessile, ovate, distantly serrate, the lower smaller and obovate: calyx-tube obconical, the lobes long-acuminate, erect, half shorter than the broadly infundibuliform corolla: flowers large, solitary, erect, dark purplish blue; style short, not exserted: caps, obovate. Mts. N. Italy. F.S. 18:1908. Gn. 60, p. 163. - One of the choicest rock-plants, but somewhat rare. Several forms of the hybrid C. Wilsonii are often cult, under this name, but their leaves are lighter green and less tomentose than C. Rainerii. Thrives in a well-drained, sunny position.
cc. Height more than 2-3 in. d. Style not exserted.
Perennial, 8-12 in., glabrous: stem ascending or prostrate: leaves leathery; root-leaves long-petioled, ovate, subcordate, irregularly serrate; stem - leaves petiolate, ovate-acute, coarsely serrate: calyx-lobes linear-lanceolate, spreading, half as long as the broadly bell-shaped corolla: flowers racemose, blue: caps, spherical. Apennines, near Naples. - This is referred by botanists to the Grecian species C. versicolor, which is typically taller, but is kept distinct by Correvon and others. In the garden, C. Tenorii resembles C. pyramidalis in foliage and flower, but is shorter.