Helianthemum
Helianthemum nummularium
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Malvales Family: Cistaceae Genus: Helianthemum Miller
Species
See text.

Helianthemem canum plant

Helianthemum (rockrose, sunroses, rushrose, or helianthemum) is a genus of about 110 species of evergreen or semi-evergreen subshrubs. They are widely distributed in the Americas, Europe, and from North Africa to Asia Minor and Central Asia, with the centre of diversity in the Mediterranean region.

The leaves are opposite, simple oval, 1-4 cm long and 0.5-2 cm broad, varying from glossy green to tomentose grey-green. The flowers are 2-4 cm diameter, with five petals, white or yellow, occasionally tinged pink; in some species the flowers are bicoloured with a brighter yellow centre to act as a 'target' for pollinating insects.

Helianthemum species are used as food plants by the larvae of some Lepidoptera species including Large Grizzled Skipper and the bucculatricid leaf-miners Bucculatrix helianthemi and Bucculatrix regaella (which both feed exclusively on Helianthemum sessiliflorum) and the Coleophora case-bearers C. bilineella, C. eupreta (feeds exclusively on H. sessiliflorum), C. ochrea (feeds exclusively on Helianthemum) and C. potentillae.

Selected species

• Helianthemum aegyptiacum
• Helianthemum almeriense
• Helianthemum apenninum - White Rockrose
• Helianthemum asperum
• Helianthemum bicknellii
• Helianthemum canadense - Frostweed
• Helianthemum canum - Hoary Rockrose
• Helianthemum caput-felis
• Helianthemum cinereum
• Helianthemum corymbosum
• Helianthemum croceum
• Helianthemum greenei - Island Rushrose
• Helianthemum hirsutissimum
• Helianthemum hirtum
• Helianthemum hymettium
• Helianthemum jonium
• Helianthemum lavandulifolium
• Helianthemum ledifolium
• Helianthemum leptophyllum
• Helianthemum lunulatum
• Helianthemum marifolium
• Helianthemum morisianum
• Helianthemum nummularium - Common Rockrose
• Helianthemum oelandicum - Alpine Rockrose (syn. Helianthemum montanum)
  • Helianthemum oelandicum subsp. oelandicum
  • Helianthemum oelandicum subsp. alpestre (syn. Helianthemum alpestre)
  • Helianthemum oelandicum subsp. italicum (syn. Helianthemum italicum)
  • Helianthemum oelandicum subsp. orientale (syn. Helianthemum orientale)
  • Helianthemum oelandicum subsp. rupifragum (syn. Helianthemum rupifragum)
• Helianthemum origanifolium
• Helianthemum pannosum
• Helianthemum papillare
• Helianthemum piliferum
• Helianthemum pilosum
• Helianthemum rossmaessler
• Helianthemum salicifolium
• Helianthemum sanguineum
• Helianthemum scoparium - Rushrose
• Helianthemum sessiliflorum
• Helianthemum songaricum
• Helianthemum spartioides
• Helianthemum squamatum
• Helianthemum stipulatum
• Helianthemum suffrutescens - Amador Rushrose
• Helianthemum villosum
• Helianthemum virgatum
• Helianthemum viscarium
• Helianthemum viscidulum

Cultivation and uses

Several Helianthemum species, and the numerous hybrids and cultivars derived from them, are widely grown as ornamental plants, popular in rockeries. A broader range of colours is available among the cultivars, including bright salmon-pink to dark red.

References

• Flora Europaea: Helianthemum
• eFloras search results for Helianthemum

External Links

• Helianthemums.co.uk for further information

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