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.
(a Centaur, famous for healing). Composite. Centaury. Dusty Miller. Bachelor's Button. Cornflower. Knapweed. Annuals or hardy and half-hardy perennials with alternate leaves, useful for bedding, vases, baskets and pots, and for borders and edgings; species many and various.
Involucre ovoid or globose, stiff and hard, sometimes prickly: receptacle bristly: marginal florets usually sterile and elongated, making the head look as if rayed. Differs from Cnicus in having the achenes obliquely attached by one side of the base or more laterally. - Species about 500, much confused, mostly in Eu., Asia and N. Africa, 1 in. N. Amer., 3 or 4 in Chile. Several Old World species have become weeds in this country. J.H. 43:76. The species are of simple cultivation, coming readily from seeds. Many of the perennial species make excellent border plants, and their blue and purple heads are welcome additions to the horde of yellow-flowering composites.
White-tomentose low plants, used for bedding or for the sake of their foliage.
(C. candidissima, Lam.). Fig. 869. Perennial: stems erect, 3 ft., branched, the entire plant white-tomentose: leaves almost all bipinnate (except the earliest), the lower petioled, all the lobes linear-lanceolate, obtuse: scales of the ovate involucre appressed, with a membranous black margin, long-ciliate, the apical bristle thicker than the others: flowers purple. S. Italy, Sicily, etc. - Much used as a bedding plant, not being allowed to bloom. The first leaves of seedlings are nearly entire (as shown in Fig. 869), but the subsequent ones become more and more cut. Grown both from seeds and cuttings. Seedlings are very apt to damp off unless care is taken in watering.
A flat, almost prostrate perennial: stem floccose - tomentose and much branched: lower leaves scarcely denticulate, the upper oblong-linear, entire: bracts of the involucre white- or black-margined: flowers showy, the blue rays about 1/2in. long. Persia, Caucasus. July.
(C. argentea, Hort. C plumosa, Hort.). Fig. 870. Perennial: entire plant covered with velvety white pubescence: stems 1 1/2-2 ft. high, erect: leaves bipinnatisect; segments linear, entire, acute: flower-heads small, in a close pani-cle, mostly hidden by the leaves; flowers rose-violet or purple. Caprea. V. 4:337. - Very ornamental on account of its velvety finely cut leaves Much used, like No. 1, for low foliage bedding: leaves more compound, and usually not so white.
Perennial, the entire plant densely white-woolly: stems erect, branching, with few leaves: root-leaves petioled, pinnate, the lobes ovate-triangular, sharp-pointed; stem - leaves sessile: flower-heads terminal on the branches, globose; involucre scales with scarious, ciliate margins, scarcely spiny; flowers yellow. Spain.
Tall-growing annual, with very narrow leaves, grown for the showy flowers
(Cyanus arvenis, Moench.) Bluebottle. Bluet. Bachelor's Button (see also Gom-phrena). Cornflower. Ragged Sailor. French Pink. Fig. 871. Annual, slender, branching, 1-2 ft. high, woolly-white when young: leaves linear, entire or the lower toothed, sometimes pinnatifid: flowers blue, purple, pink or white, the heads on long, naked stems: involucral bracts rather narrow, fringed with short, scarious teeth. S. E. Eu. Gt. 38, p. 641; 39, p. 537. V. 5, p. 44; 13:361. - One of the most popular of garden flowers, variable. It is perfectly hardy, blooming until frost and coming up in the spring from self-sown seed. The following are varieties of this: Pure White; Victoria, a dwarf, for pots and edgings (Gn. 40, p. 147); Emperor William, fine dark blue; flore pleno, with the outer disk-As. converted into ray-flowers; nana compacta, dwarf. (Gt. 44, p. 150.) Centaurea Cyanus is one of the "old-fashioned flowers," everywhere well known and popular-It often escapes from gardens.
Fig. 869. Lower leaf from a young plant of Centaurea Cineraria. (X 1/2)
Fig. 870. Radical leaf of Centaurea gymnocarpa.
Fig. 871. Centaurea Cyanus. (X 1/2) pinnate, the upper pinnate, all with very narrow, linear, entire, acute lobes: flower-heads subglobose; scales of the involucre with a rounded almost entire rather lax tip; flowers purple. Spain, Italy.
Straight-growing smooth annuals or perennials, with dentate Ivs., grown for the large fragrant heads.
(C. suaveolens, Linn. C. odorata, Hort. C. Amberboii, Mill. Amberbba moschata, Less.). Sweet Sultan. Fig. 872. Annual: stems 2 ft. high, branching below, erect: whole plant 6mooth, bright green: leaves pin-natifid, the lobes dentate: flower-heads long-peduncled; involucre round or ovate, smooth, only the innermost of the involucral scales with scarious margins: flowers white, yellow or purple, fragrant. Orient. Mn. 4, p. 149. Gn. 54:372. I.H. 42, p. 106. Gng. 4:147. G. 5: 289; 16:267; 25:71.
Fig. 872. Centaurea moschata. (X 1/4) lanceolate or ovate, entire, ribbed: flowers with 4-lobed calyx, 4 petals, 8 stamens, and a 4-loculed ovary, pink or white, in axillary or terminal clusters. - Species 4-6, in Mex. and Cent. Amer. They fall into 2 groups,-those with very unequal stamens, and C. floribunda with nearly equal stamens.
Variety alba, Hort. (C. Mar-garitae, Hort.). Flowers white. Gn. 19, p. 337; 54:372. A.G. 13: 607. This form, known as C. Margaritae, is pure white and very fragrant. It was introduced by an Italian firm in 1891. variety rubra, Hort. Flowers red. Gn. 54:372. - A popular, old-time garden flower, with long-stalked heads; of easy cultivation It does not bear transplanting well. - C. imperialis, Hort., is said to be the offspring of C. moschata and C. Margaritae, introduced into the American trade in 1899. Gn.M. 13:74. Plants are said to inherit the vigorous free growth of C. moschata, being of the same easy cult, and forming clumps 3-4 ft. high. The flowers resemble C. Margaritae, but are twice as large and abundantly borne on long stems from July until frost. They range through white, rose, lilac and purple, are fragrant, and if cut when first open will keep 10 days. C. Mariae, Hort., introduced 1899, resembles C. imperialis, but the flowers open sulfur-yellow, become lighter, and are tipped with rose.
All sweet sultans do best if the bloom is secured before very hot weather.