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. Heaths hardy, European, or hardy with protection from New York southward. b. Leaves and calyx-seams, ciliate: stamens included.
c. Flowers in spike-like clusters....... 1. ciliaris cc. Flowers in umbel-like clusters....... 2. Tetralix bb. Leaves and calyx-segments glabrous. c. Anthers usually exserted well beyond the corolla-tube. D. Flowers usually solitary and lateral, rose-colored........... 3. mediterranea dd. Flowers clustered, pink, usually all lateral................. 4. carnea ddd. Flowers all clustered at the ends of the branches.............. 5. vagans cc. Anthers included in the corolla-tube. d. Flowers rose-violet or purplish.
e. The leaves verticillate in 3's.... 6. cinerea ee. The leaves verticillate in 4's.. 7. stricta dd. Flowers pale rose, in broad panicles.................. 8. lusitanica
AA. Heaths tender, S. African, always grown under glass in Amer. b. Flowers mostly showy, petal-like, scarcely greenish or sepal-like. c. Corolla tubular, the limb not spreading. d. Length of flowers usually more than 6 lines, in cult, specimens umbellate............ 9. verticillata dd. Length of flowers usually 10-12 lines, in 2's or 3's.........10. hyemalis cc. Corolla various, not tubular, the limb often spreading. d. The corolla-segments spreading, the tube mostly elongate. E. Length of corolla 6-8 lines; segments ovate, acute........11. ventricosa ee. Length of corolla 3-4 lines; segments ovate or sub-orbicular ...................12. praestans dd. The corolla-segments usually not spreading, the tube rarely over 4 lines long. e. Leaves channeled.
F. The leaves in 3's..........13. sicaefolia ff. The leaves in 4's..........14. propendens ee. Leaves not channeled, more or less open-backed and spreading. F. Infloresence variable, often terminal and axillary on the same plant........15. flacca ff. Infloresence always terminal.
G. Sepals about as long as the corolla-tube. H. Leaves rough or tuberculate............16. turrigera hh. Leaves not rough.
1. The leaves glabrous... 17. gracilis ii. The leaves usually pubescent.......18. persoluta
GG. Sepals about half as long as the corolla-tube ...............19. formosa bb. Flowers not so showy, calyx-like, the calyx often colored also.
c. Leaves in 3's: sepals colored.......20. melanthera cc. Leaves opposite: sepals green......21. fragrans
1. ciliaris, Linn. A much-branched nearly hardy shrub, 10-20 in. tall, the branches usually glandular: leaves small, but not as in typical heaths, ovate, mucro-nate: flowers about 4 lines long, or more, purplish, in spike-like, lateral clusters. Eu. June-Sept. B.M. 8443.
2. Tetralix, Linn. Bell Heather. Cross-leaved Heath. Leaves in 4's, margin folded back: flowers rosy; sepals ovate-lanceolate, ciliate; anthers awl-shaped or awned, included; ovary with short, soft hairs. W. Eu. - Foliage grayish. Height in England 6-12 in. With Manning, at Reading, Mass., about 8 in.
3. mediterranea, Linn. (E. carnea variety occidentdlis, Benth.). Fig. 1411. This is considered by Bentham a western form of E. carnea (No. 4), with a little smaller flowers, corolla a trifle wider at the apex, and anthers shortly exserted instead of included. E. mediterranea of the trade is hardy in England, and perhaps second only to E. carnea in popularity there. In Amer, it seems to be cult, only under glass but should be hardy from N. Y. southward with protection. B.M. 471. Gn. 54:263; 55, p. 403; 61, p. 431. G.M. 45:261; 55:315. variety alba, a white-flowered form is known. Gn. 59, p. 94.
4. carnea, Linn. (E. herbacea, Linn.). Height 6 in.: leaves in 4's: infloresence lateral; corolla broadly bell-shaped; anthers exserted; ovary glabrous. March-May. Alps. L.B.C. 15:1452. B.M. 11. Gn. 54:6 (a charming picture). - The bright rosy-flowered form is the best and most striking. There are pale red and pure white varieties. The most popular of all hardy ericas. Very easily prop, by division. E. mediterranea variety hybrida, Hort., is said to be a cross with E. carnea, and in England thriving almost as well in loam as in peat. See Gn. 54:262; 55, p. 127; 61, p. 399; 72, p. 176. G.M. 50: 39. J.H. 111.51:293.
5. vagans, Linn. Cornish Heath. Fig. 1412. Leaves in 4's or 5's: sepals small, ovate, obtuse; corolla ovate-bell-shaped; anthers ovate-oblong, 2-parted, exserted; ovary not hairy. W. Eu. and Medit. - Flowers pale purplish red. Grows 3-4 ft. in England; 1 ft. with J. W. Manning, Reading, Mass. variety alba has white flowers variety capitata, grows 1-2 ft. high with Meehan at Ger-mantown, 'Pa., and has "small whitish flowers with a purplish tip." F.E. 22:685.
6. cinerea, Linn. A twisted and much-branched shrub, 8-15 in. high: leaves verticillate, in 3's, narrow, glabrous, and usually not over 3 lines long: flowers showy, rose-violet, in usually verticillate clusters; corolla much contracted at apex, the lobes reflexed. June-Sept. Eu. variety alba, Hort., a white-flowered form, and variety coccinea, Hort., a scarlet form, are both in the trade. Gn. 61, p.
Fig. 1411. Erica mediterranea.
Fig. 1412. Erica vagans. (X 1/4)
433. - Hardy in U. S., with a little protection, from N. Y. southward.
7. stricta, Don. Corsican Heath. Leaves in 4's, a little more erect than in No. 2: sepals lanceolate, obtuse; corolla ovoid-oblong, narrowed at the throat; anthers awl-shaped or awned, included; flowers rosy purple; ovary densely covered with long, rough hairs. Corsica. - Summer. Attains 4 ft. in Eng., but grows 1-2 ft. high with Meehan, at German-town, Pa. Branches strict, rigid.
8. lusitanica, Rudolph (E. co-donodes, Lindl.). Spanish Heath. Branches tomentose - pubescent: leaves glabrous and ovary glabrous: flowers pale rose, in broad panicles. W.Eu. B.R.1698. G.C.II. 7:463; III. 19:487; 35:91. I.H. 43, p. 321. Gn. 54:263; 55, p. 125; 67, p. 328. B.M. 8018. G. 21:384; 30:130. - Hardy in England, but in U. S. only south of N. Y., and then must be protected.
9. verticillata, Berg. An erect shrub, 4-6 ft., with leaves 4-6 in a whorl: leaves densely imbricate, erect or spreading: flowers mostly in 4's in wild specimens, but, according to Andrews, umbellately 3-10-flowered in cultivation; corolla tubular, hairy, usually straight, bright rosy-scarlet, and very showy: caps, unique in splitting into 8 valves. Andr. Heathery, 58.
10. hyemalis, Hort. Fig. 1413. Written also hie-malis. Watson thinks it may be a winter-flowering form of E. perspicua, figured in L.B.C. 2:102 and 18: 1778 as. E. Linnaeana. Flowers rosy pink, tipped white. variety alba has white flowers With L. Dupuy, Whitestone, L. I., it flowers in Sept. G.F. 5:137. Gn. 41:420. G. 25:567. H. D. Darlington says it is very distinct from E. perspicua.
Fig. 1413. Erica hyemalis. Great numbers of this heath are sold in London every Christmas.