|Helianthemum subsp. var.|
Plant description here...
|Standard Cyclopedia of Horticulture|
Helianthemum (Greek for sun flower). Including Halimium, Tuberaria and Fumana. Cistaceae. Sun Rose. Ornamental woody or herbaceous plants grown chiefly for their showy flowers.
Half-evergreen or evergreen low, upright or prostrate shrubs or perennial herbs, rarely annual: lvs. usually opposite, or the upper ones alternate, rarely all alternate, small, entire, with or without stipules: fls. in terminal racemose, umbellate or subcapitatc cymes, rarely solitary, mostly yellow, sometimes of 2 kinds, earlier fls. with large petals and later fls. with small or without petals; sepals 3, or 5 and unequal; petals 5; stamens many; ovary 1 - celled or imperfectly 3-celled, with slender or short style; caps. 3-valved with many or several seeds; embryo curved like a ring or hook (subgen. Halimium), or straight or folded (Helianthemum proper).—About 110 species in N. Amer. (and 3 in. S. Amer.), Eu., N. Afr. and W. Asia. Monograph by Grosser in Engler, Das Pflanzenreich, hft. 14. Cistacesr, pp. 33-131 (1903); another important work is Sweet's Cistineso (1825-30) where many species are figured, quoted below as S. C.
The helianthemums are mostly suffruticose or shrubby, less often herbaceous plants, either upright and low, or cespitose or prostrate, with small and usually narrow, often grayish foliage and with yellow or white, less often pink or red, usually profusely produced flowers in terminal racemes or clusters, rarely solitary, appearing during the summer and followed by a capsular fruit inclosed or surrounded by the persistent sepals; the flowers open only in the sun and the delicate petals soon drop. Most of the species are not hardy- North without protection and are particularly suited to warmer and drier climates, but H. charmecistus is fairly hardy North, though in exposed situations it also profits by a protection of mulch: the hardiest of the species mentioned below is H. canadense, but it is at the same time the least attractive. They all thrive well in poor sandy or rocky soil, most of them being partial to limestone soil, and demand a sunny position to bloom profusely. They are especially adapted for rockeries and borders particularly the numerous forms of H. chamseciistus which form dense mats; most of the other species are of low twiggy habit. Propagation is mostly by division, also by greenwood cuttings and by seeds which germinate readily, but if several species are grown together the seeds are liable to produce hybrids.
Pests and diseases
algarvense, 2. hyssopifolium, 1, rhodanthum , 6. angustifolium, 7. lasianthum. 3. roseum, 6, 7, 8. appeninum, 6. macranthum, 7. stramineum, 7. canadense, 1. multiplex. 7. sulphureum, 8. chamaecistus, 7. mutabile, 7. tomentosum, 7. cupreum, 7, 8. ocymoides, 2. umbellatum, 4. diversifolium, 7. pilosum, 5. variabile, 7. formosum, 3. polifolium, 6, 7. venustum, 7. grandiflorum, 7. pulverulentum, 6. vulgare, 7.
H. alpestre., Dun. (H. oelandicum var. alpeetre, Bentb.). Cespitose subshrub: lvs. ovate-lanceolate to lanceolate, hairy or glabrescent, ½ - ¾ in. long: fl. yellow, ½ in. across. Mountains of S. Eu. S.C. 2.—H. globulariaefolium. Pere. (Tuberaria globulariifolia, Willk.). Perennial; lvs. mostly radical, long-stalked, ovate, hairy, 1-2 in. long: Ms. in simple or branched racemes, yellow with purple eye, 1 ¾ in. across. S. Eu., N. Afr. B.M. 4873 (as H. tuberaria).H. lunulatum. Lam. Cespitose subshrub: lvs. elliptic-oblong, green on both aides, glabrescent or sparingly hairy, 1/3 – ½ in, long: fls. solitary, yellow, ½ in. across; petals with crescent- shaped spot at the base. Italy. R.F.G. 3:26 (4529).—H. tuberaria, Mill. (Tuberaria vulgaris, Will.). Perennial: lvs. mostly radical, oval-lanceolate to obovate, grayish tomentose beneath, 1-3 in. long: 3s. in simple or branched racemes, yellow, 1 ½ in. across. S. Eu., Afr. S.C. 18.—H. Tuberaria, Hook. f.=H. globulariaefolium.CH
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963