7. Glastifolia, Linn

A strong-growing border perennial with a rough much-branched and winged stem: leaves oblong, entire, decurrent, the basal leaves petiolate, sometimes divided: flowers yellow, the heads solitary, without bracts, and quite smooth. Cent. Eu. B.M. 62. June-Sept.

aaaa. Other Centaureas of various kinds, occasionally grown in hardy borders, for their flowers or imposing stature. See page 3567.

b. Foliage green on both sides. c. Leaves pinnate or bipinnate.

8. Splendens, Linn

(C. Margaritacea, Ten.). Perennial: stems erect, branched: leaves smooth, the lowest bi-

9. Ruthenica, Lam

Hardy perennial about 3 ft.: stem erect, branching, smooth: leaves pinnatisect, the lobes linear-toothed, sharply narrowed at both ends, the base often somewhat decurrent: flower-heads usually solitary, the pale-yellow rays about 3/4in. long; pappus double: achenes glabrous. Cent. Eu. July. G.26:630.

cc. Leaves entire or dentate, not pinnatisect.

10. Americana, Nutt

(Plectocephalus americanus, Don). Basket Flower. Fig. 873. Hardy annual, nearly smooth: stems stout, simple or sometimes a little branched, 2-5 ft., thickened under the naked head: leaves mostly entire, oblong - lance-shaped, mucronate: involucre 1/2-1 1/2 in. diam., its bracts all with fringed scarious appendages: flowers rose or flesh-colored, sometimes purplish; disk 1-3 in. diam.; narrow lobes of the ray-flowers often 1 in. long. Mo. and Ark. to La. and Mex. F.S. 4:327. S.H. 2:223. A.F. 16: 1644 (alba). Gng. 9:341 (alba). -Very attractive.

Centaurea americana. (X1/2)

Fig. 873. Centaurea americana. (X1/2)

11. Macrocephala, Puschk

Perennial: stems simple, erect, swollen below the flower-head, leafy, 2 1/2-3 ft. high: leaves ovate-lanceolate, slightly decurrent, scabrous, acute, somewhat serrate, gradually diminishing upwards to the base of the single terminal head: head subglobose, larger than a hen's egg, often 3-4 in. diam.; involucre of 8-12 rows of appressed, scari-ous-margined, rusty, fringed scales; flowers yellow, the marginal and disk alike. Armenia. B.M. 1248. J.H. III. 33:331; 52: 547; 63: 319. - Often grown from seeds.

12. Nigra, Linn. Knapweed

Hardheads. Perennial, 1-2 ft. high: stems branching, rough pubescent: leaves lance-shaped and entire or lower sparingly toothed or lobed, but not pin-natifid: involucral bracts with pectinate-ciliate-fringed black appendages: flowers all alike, the disk and marginal ones of the same size. Eu. variety variegata, Hort. Leaves edged with creamy white, tufted. A very striking border plant; useful in dry or open places.

bb. Foliage white or tomentose, at least beneath (often green above).

c. stems low, weak, not strict.

13. Leucophylla, Bieb

(C. declinata, Bieb.). Perennial: stems short, decumbent, with very few leaves: root-leaves petioled, tomentose-woolly on both sides, pinnate, the ovate lobes undulate, sparsely cut-lobed or sinuate-toothed: flower-head with few bracts, solitary, terminal; 6cales of the ovate involucre lanceolate, acuminate, brown, long-ciliate; flowers purple. Caucasus.

14. Montana, Linn

Mountain Bluet. Perennial: stems low, stoloniferous, unbranched, 12-16 or rarely 20 in. high: Ivs. decurrent, the young ones silvery white, oval-lance-shaped: involucre of 4 or 5 rows of scales, black-ciliate along the margins: flowers blue, the marginal ones 1 in. long; disk-As. very short, becoming purple. Eu. B.M.77. G.M. 47:243. varietyalba, Hort. Flowerswhite. G. 25:71; 29:109. G.M. 51:162. variety rosea, Hort. Flowers rose-colored. variety citrina, DC. (variety sulphured, Hort.). Disk-flowers brown, rays yellow. Armenia. B.M. 1175 (asC.ochroleuca).

cc. stems erect, simple or branched.

15. Dealbata, Willd

Perennial: stems sub-erect, 8-24 in. high: leaves white-villous beneath, glabrous above, the lower ones 1-1 1/2 ft. long, petioled, pinnate, the obovate lobes coarsely cut-toothed or auricled at the base; stem - leaves sessile, pinnate, with oblong-lance lobes: flower-head solitary, just above the uppermost If.; flowers red, those of the disk rosy or white; outer scales of the involucre with lanceolate tips, the middle rounded, deeply fringed, ciliate. Asia Minor, Persia. J.H. III. 46:515.

16. Nervosa, Willd

A stout perennial about 2-2 1/2 ft. tall with a simple unbranched rough stem: lower leaves glandular, usually slightly toothed, the stem - leaves clasping by the auriculate base; heads solitary, the rays deep purple. A branched and numerous-fid. form is known in the wild but not to the trade. Cent. Eu. July., Aug.

17. Atropurpftrea, Waldst. & Kit

(C. calo-cephala, Willd.). Perennial: stems erect, branched, about 2-3 ft. high, the branches white-woolly at the summit: leaves bipinnate, lobes linear-lanceolate, acuminate; lowest leaves petioled, uppermost pinnatifid: flower-heads without bracts; invol-ucral scales with fringed ciliate white lanceolate tips, the innermost ones rounded, scarious-margined; flowers black-purple. Hungary.

18. Babylonica, Linn

Silvery white perennial: stems simple, stout, erect, 6-10 or 12 ft. high: leaves long, coriaceous, strongly decurrent on the stem, the radical lyrate, the lower stem - leaves oval or oblong-acute, entire or undulate, the upper lance-acute: flowers yellow, the globular heads almost sessile in the axils of narrow bract-like leaves; one-third to half of the stem flower-bearing; involucre-scales with a short, recurved tip. Asia Minor, Syria. Gn. 2, p. 73; 8, p. 263. R.H. 1859, pp. 540-1. - Tall, stout and striking plant.

C. alpina, Linn. Leaves downy beneath, prickly: flower-heads yellow; scales of involucre ovate, obtuse: hardy herb, 3 ft., from Eu., sometimes seen in collections. - C. eridphora, Linn. A low plant with a spiny calyx and silvery leaves, is cult, in England. Not known in Amer. - C. pulcherrima, Willd. AEtheopappus puloherrimus, Hort.). A stout hardy perennial about 2 1/2 ft. with brilliant rose flowers is known in the trade. - C. rigidifolia, Hort. Stout perennial, 2 1/2 ft., with crimson heads is apparently C. orientalis, Linn. - Not much known in U. S. N. Taylor †