Helianthemum (),Sunset Western Garden Book. 1995. 606–07. known as rock rose, sunrose, rushrose, or frostweed,Helianthemum. Integrated Taxonomic Information System (ITIS). is a genus of about 114Helianthemum. Flora of China. species of flowering plants in the family Cistaceae. They are widely distributed throughout the Northern Hemisphere, especially in the Mediterranean.
New World species formerly classified as Helianthemum have been transferred to genus Crocanthemum.Sorrie, B. A. (2011). Transfer of North American Helianthemum to Crocanthemum (Cistaceae): New combinations. Phytologia 93(2), 270-71.
Description These are usually shrubs or subshrubs, and some are herbaceous annuals or perennials. The leaves are oppositely arranged, but some plants may have alternately arranged leaves along the upper stems. The flowers are solitary or borne in an array of inflorescence types, such as panicles, racemes, or headlike clusters. The flower has three inner sepals and two smaller outer sepals. It has five petals usually in shades of yellow, orange, or pink. The style at the center is tipped with a large stigma. The fruit is a capsule containing many seeds.
Ecology Helianthemum are known to form symbioses with mycorrhizal fungi. In the Mediterranean they are associated with Terfeziaceae, the desert truffles. Together, plant and fungus may have a beneficial effect on the arid local landscapes, preventing soil erosion and desertification. Some symbiotic pairs include Helianthemum salicifolium and the truffle Tirmania nivea, and H. guttatum and T. pinoyi.Díez, J., et al. (2002). Molecular phylogeny of the mycorrhizal desert truffles (Terfezia and Tirmania), host specificity and edaphic tolerance. Mycologia 94(2), 247-59.
One of the most commonly observed mycorrhizae on Helianthemum is a member of a different family, Cenococcum geophilum. This fungus is not host-specific, and it often associates with oaks, as well. Some studies suggest that Helianthemum and oaks growing together in a habitat may "share" their mycorrhizae.
Helianthemum are food plants for the larvae of some Lepidoptera species, such as the large grizzled skipper and the silver-studded blue. The leaf miners Bucculatrix helianthemi and B. regaella both feed exclusively on Helianthemum sessiliflorum, as does Coleophora eupreta. C. ochrea is limited to Helianthemum, and C. bilineella and C. potentillae have been observed on the genus.
Cultivation 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. They are best grown in well-draining soil in full sun, and have a long flowering period from spring to summer. Numerous cultivars have gained the Royal Horticultural Society's Award of Garden Merit:
'Amy Baring' (yellow) 'Fire Dragon' 'Henfield Brilliant' (scarlet) 'Jubilee' (pale yellow) 'Mrs C.W. Earle' (red) 'Rhodanthe Carneum' (pink) 'The Bride' (white) 'Wisley Primrose' (primrose yellow)
Species
The following species are accepted. Helianthemum abelardoi Helianthemum aegyptiacum Helianthemum aganae Helianthemum aguloi Helianthemum almeriense Helianthemum alypoides Helianthemum angustatum Helianthemum antitauricum Helianthemum apenninum – white rockrose Helianthemum × asperilanceolatum Helianthemum asperum Helianthemum assadii Helianthemum baschkirorum Helianthemum bilyanense Helianthemum bramwelliorum Helianthemum broussonetii Helianthemum buschii Helianthemum bystropogophyllum Helianthemum canariense Helianthemum canum Helianthemum capralense Helianthemum caput-felis Helianthemum × carmen-joanae Helianthemum × carolipaui Helianthemum cinereoflavescens Helianthemum cinereum Helianthemum cirae Helianthemum ciscaucasicum Helianthemum citrinum Helianthemum × conchitae Helianthemum concolor Helianthemum confertum Helianthemum × coronadoi Helianthemum coulteri Helianthemum crassifolium Helianthemum × crespoi Helianthemum croceum Helianthemum cylindrifolium Helianthemum dagestanicum Helianthemum dianicum Helianthemum × digeneum Helianthemum × doumerguei Helianthemum edetanum Helianthemum ellipticum Helianthemum eriocephalum Helianthemum × fabadoi Helianthemum × finestratense Helianthemum fontanesii Helianthemum geniorum Helianthemum germanicopolitanum Helianthemum getulum Helianthemum glaucescens Helianthemum gonzalezferreri Helianthemum gorgoneum Helianthemum grosii Helianthemum guerrae Helianthemum × guiraoi Helianthemum hadedense Helianthemum × heerii Helianthemum henriquezii Helianthemum hirtum Helianthemum × hispidum Helianthemum hymettium Helianthemum inaguae Helianthemum juliae Helianthemum kahiricum Helianthemum kotschyanum Helianthemum × lagunae Helianthemum ledifolium Helianthemum leptophyllum Helianthemum linii Helianthemum lippii Helianthemum × lucentinum Helianthemum lunulatum Helianthemum × mansanetianum Helianthemum × mariano-salvatoris Helianthemum marifolium Helianthemum maritimum Helianthemum marminorense Helianthemum marmoreum Helianthemum mathezii Helianthemum × monspessulanum Helianthemum × montis-bovis Helianthemum morisianum Helianthemum motae Helianthemum × moyense Helianthemum × murbeckii Helianthemum neopiliferum Helianthemum nummularium – common rockrose Helianthemum obtusifolium Helianthemum oelandicum – alpine rockrose, hoary rockrose (syn. Helianthemum montanum) Helianthemum oelandicum subsp. alpestre (syn. H. alpestre) Helianthemum oelandicum subsp. italicum (syn. H. italicum) Helianthemum oelandicum subsp. oelandicum Helianthemum oelandicum subsp. orientale (syn. H. orientale) Helianthemum oelandicum subsp. rupifragum (syn. H. rupifragum) Helianthemum oelandicum Helianthemum ordosicum Helianthemum origanifolium Helianthemum pannosum Helianthemum papillare Helianthemum patens Helianthemum pergamaceum Helianthemum × petrerense Helianthemum polyanthum Helianthemum polygonoides Helianthemum pomeridianum Helianthemum × protodianicum Helianthemum × pseudodianicum Helianthemum pugae Helianthemum raskebdanae Helianthemum × rigualii Helianthemum rossmaessleri Helianthemum rotundifolium Helianthemum ruficomum Helianthemum salicifolium Helianthemum sancti-antoni Helianthemum sanguineum Helianthemum sauvagei Helianthemum schweinfurthii Helianthemum scopulicola Helianthemum sessiliflorum Helianthemum sicanorum Helianthemum sinuspersicum Helianthemum somalense Helianthemum songaricum Helianthemum speciosum Helianthemum squamatum Helianthemum stipulatum Helianthemum strickeri Helianthemum × subhispidulum Helianthemum × subviscosum Helianthemum × sulphureum Helianthemum supramontanum Helianthemum syriacum Helianthemum syrticum Helianthemum teneriffae Helianthemum tholiforme Helianthemum thymiphyllum Helianthemum × triregnorum Helianthemum ventosum Helianthemum vesicarium Helianthemum violaceum Helianthemum virgatum Helianthemum viscarium Helianthemum viscidulum Helianthemum × xixonense Helianthemum zheguliense
References
External links
Flora Europaea: Helianthemum eFloras search results for Helianthemum