Saxifraga is the largest genus in the family Saxifragaceae, containing about 473 species of holarcticperennial plants, known as saxifrages[1][2] or rockfoils.[3] The Latin word saxifraga means literally "stone-breaker", from Latinsaxum ("rock" or "stone") + frangere ("to break"). It is usually thought to indicate a medicinal use for treatment of urinary calculi (known as kidney or bladder stones), rather than breaking rocks apart.[2][4]
The inflorescence or single flower clusters rise above the main plant body on naked stalks. The small actinomorphichermaphrodite flowers have five petals and sepals and are usually white, but red to yellow in some species. Stamens, usually 10, rarely 8, insert at the junction of the floral tube and ovary wall, with filaments subulate or clavate. As in other primitive eudicots, some of the 5 or 10 stamens may appear petal-like.[citation needed] and it lives in tundral ecosystems.[5][8][6]
Taxonomyedit
A genus of about 473 species.[1] The former monotypic genus Saxifragella has been submersed within Saxifraga, the largest genus in Saxifragaceae, as Saxifraga bicuspidata.[9][5] Also the genus Saxifragopsis (strawberry saxifrage) was previously included in Saxifraga.[10]
Subdivisionedit
Based on morphological criteria, up to 15 sections were recognised.[11] Subsequent molecular phylogenetic studies reduced this to 13 sections with 9 subsections. The former sections Micranthes and Merkianae are more closely related to the Boykinia and Heucheraclades.[12] Modern floras separate these groups as the genus Micranthes.[13][6]
Pepper-saxifrage, Silaum silaus. The name "silaum" comes from the Latin word sil, which means yellow ochre. This refers to the sulphurous yellow colour of the flowers.[17]
Some plants refer to Saxifraga in their generic names or specific epithets, either because they are also "rock-breaking" or because they resemble members of the saxifrage genus:[citation needed]
Saxifrages are typical inhabitants of Arctic–alpineecosystems, and are hardly ever found outside the temperate parts of the Northern Hemisphere; most members of this genus are found in subarctic climates. A good number of species grow in glacial habitats, such as S. biflora which can be found some 4,000 m (13,000 ft) above sea level in the Alps, or the East Greenland saxifrage (S. nathorstii). The genus is also abundant in the Eastern and Western Himalayan alpine shrub and meadows. Though the archetypal saxifrage is a small plant huddling between rocks high up on a mountain, many species do not occur in such a habitat and are larger (though still rather delicate) plants found on wet meadows.
Charles Darwin – erroneously believing Saxifraga to be allied to the sundew family (Droseraceae) – suspected the sticky-leaved round-leaved saxifrage (S. rotundifolia), rue-leaved saxifrage (S. tridactylites) and Pyrenean saxifrage (S. umbrosa) to be protocarnivorous plants, and conducted some experiments whose results supported his observations,[19] but the matter has apparently not been studied since his time.
Cultivationedit
Numerous species and cultivars of saxifrage are cultivated as ornamental garden plants, valued particularly as groundcover or as cushion plants in rock gardens and alpine gardens. Many require alkaline or neutral soil to thrive.[7]
S. × urbium (London pride), a hybrid between Pyrenean saxifrage (S. umbrosa) and St. Patrick's cabbage (S. spathularis), is commonly grown as an ornamental plant.[2] Another horticultural hybrid is Robertsoniana saxifrage (S. × geum), derived from kidney saxifrage (S. hirsuta) and Pyrenean saxifrage.[citation needed] Some wild species are also used in gardening. Cambridge University Botanic Garden hosts the United Kingdom's national collection of saxifrages.[2]
The leaves of some saxifrage species, such as creeping saxifrage (S. stolonifera) and S. pensylvanica,[51] are edible. The former is a food in Korea[52] and Japan.[citation needed] The flowers of purple saxifrage (S. oppositifolia) are eaten in Nunavut, Canada and the leaves and stems brewed as a tea.[53]
Species are also used in traditional medicine, such as creeping saxifrage in East Asia[54] and round-leaved saxifrage (S. rotundifolia) in Europe.[55]
Two species—purple saxifrage and creeping saxifrage—are popular floral emblems. They are official flowers for:
^ abcdefghijklmnopqrstuvwxUmberto Quattrocchi. CRC World Dictionary of Plant Names: Common Names, Scientific Names, Eponyms. Synonyms, and Etymology. CRC Press, 1999. p.2395-2396. ISBN 9780849326738
^Knaben, G. (1934). "Saxifraga osloensis n. sp., a tetraploid species of the Tridactylites section". Nytt Magasin for Botanikk: 117–138.
^Reader's Digest Nature Lover's Library Wild Flowers of Britain, page 192, published 1988
^Ivo Novák (1980). A Field Guide in Colour to Butterflies and Moths. Octopus Books. ISBN 0-7064-1293-1.
^Charles Darwin (1875). "Drosophyllum – Roridula – Byblis – glandular hairs of other plants – concluding remarks on the Droseraceae". Insectivorous Plants (1st ed.). London: J. Murray. pp. 332–367.
^"AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 95. Retrieved 1 November 2018.
^"RHS Plantfinder - Saxifraga 'Angelina Johnson'". Retrieved 1 November 2018.
^"RHS Plantfinder - Saxifraga 'Blackberry and Apple Pie'". Retrieved 1 November 2018.
^"RHS Plant Selector - Saxifraga callosa". Retrieved 5 March 2021.
^"RHS Plantfinder - Saxifraga 'Conwy Snow'". Retrieved 1 November 2018.
^"RHS Plantfinder - Saxifraga 'Coolock Kate'". Retrieved 1 November 2018.
^"RHS Plantfinder - Saxifraga 'Cumulus'". Retrieved 1 November 2018.
^"RHS Plant Selector - Saxifraga fortunei". Retrieved 5 March 2021.
^"RHS Plantfinder - Saxifraga 'Venetia' (paniculata)". Retrieved 1 November 2018.
^"RHS Plantfinder - Saxifraga 'Whitehill'". Retrieved 1 November 2018.
^Niering, William A.; Olmstead, Nancy C. (1985) [1979]. The Audubon Society Field Guide to North American Wildflowers, Eastern Region. Knopf. p. 780. ISBN 0-394-50432-1.
^Chon, Sang-Uk; Heo, Buk-Gu; Park, Yong-Seo; Cho, Ja-Yong; Gorinstein, Shela (2008). "Characteristics of the leaf parts of some traditional Korean salad plants used for food". Journal of the Science of Food and Agriculture. 88 (11): 1963–1968. Bibcode:2008JSFA...88.1963C. doi:10.1002/jsfa.3304. ISSN 1097-0010.
^Ji-xian Guo, Ki Sung Chung, Paul Pui-hay But, Takeatsu Kimura (1996). International Collation Of Traditional And Folk Medicine, Vol 2: Northeast Asia Part 2. World Scientific Publishing Company. p. 65.{{cite book}}: CS1 maint: multiple names: authors list (link)
^Pieroni, Andrea; Quave, Cassandra L., eds. (2014). Ethnobotany and Biocultural Diversities in the Balkans. New York: Springer.
^"The Official Flower of Nunavut: Purple Saxifrage". Legislative Assembly of Nunavut. 2011. Retrieved July 31, 2011.
^County flowers in Britain Archived 14 February 2006 at the Wayback Machine www.plantlife.org.uk
^"City flower, bird and tree" (in Japanese). City of Tsukuba. Retrieved 17 June 2021.
Bibliographyedit
Books
Gornall, RJ (2011) [1984]. "Saxifraga". In Cullen, James; Knees, Sabina G.; Cubey, H. Suzanne (eds.). The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass. Vol. III Angoiospermae - Dicotyledons (Resedaceae - Cyrillaceae) (2nd ed.). Cambridge University Press. pp. 102–131. ISBN 978-0-521-76155-0.
Soltis, D E (2007). "Saxifragaceae". In Kubitzki, Klaus (ed.). Flowering Plants. Eudicots: Berberidopsidales, Buxales, Crossosomatales, Fabales p.p., Geraniales, Gunnerales, Myrtales p.p., Proteales, Saxifragales, Vitales, Zygophyllales, Clusiaceae Alliance, Passifloraceae Alliance, Dilleniaceae, Huaceae, Picramniaceae, Sabiaceae. The Families and Genera of Vascular Plants. Vol. IX. Springer. pp. 418–435. ISBN 978-3-540-32219-1.
Deng, Jia-bin; Drew, Bryan T.; Mavrodiev, Evgeny V.; Gitzendanner, Matthew A.; Soltis, Pamela S.; Soltis, Douglas E. (February 2015). "Phylogeny, divergence times, and historical biogeography of the angiosperm family Saxifragaceae". Molecular Phylogenetics and Evolution. 83: 86–98. doi:10.1016/j.ympev.2014.11.011. PMID 25479063.
Gornall, Richard J. (December 1987). "An outline of a revised classification of Saxifraga L.". Botanical Journal of the Linnean Society. 95 (4): 273–292. doi:10.1111/j.1095-8339.1987.tb01860.x.
Gornall, Richard J.; Ohba, Hideaki; Jintang, Pan (2000). "New Taxa, Names, and Combinations in the Saxifraga (Saxifragaceae) for the Flora of China". Novon. 10 (4): 375–377. doi:10.2307/3392990. JSTOR 3392990.
Soltis, Douglas E.; Kuzoff, Robert K.; Conti, Elena; Gornall, Richard; Ferguson, Keith (March 1996). "matK and rbcL Gene Sequence Data Indicate that Saxifraga (Saxifragaceae) is Polyphyletic". American Journal of Botany. 83 (3): 371. doi:10.2307/2446171. JSTOR 2446171.
Tkach, Natalia; Röser, Martin; Miehe, Georg; Muellner-Riehl, Alexandra N.; Ebersbach, Jana; Favre, Adrien; Hoffmann, Matthias H. (31 December 2015). "Molecular phylogenetics, morphology and a revised classification of the complex genus Saxifraga (Saxifragaceae)". Taxon. 64 (6): 1159–1187. doi:10.12705/646.4.
Websites
POWO (2019). "Saxifraga Tourn. ex L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 1 December 2019.
WFO (2020). "Saxifraga L." World Flora Online. Retrieved 9 January 2020.
"The Saxifrage Society". 2020. Retrieved 9 January 2020.
Floras
Jintang, Pan; Gornall, Richard; Ohba, Hideaki (2004). "Saxifraga Linnaeus, Sp. Pl. 1: 398. 1753 (虎耳草属hu er cao shu)". p. 280. Retrieved 9 January 2020., in Flora of China online vol. 8 see also PDF
Brouillet, Luc; Elvander, Patrick E. (2008). "Saxifraga Linnaeus, Sp. Pl. 1: 398. 1753; Gen. Pl. ed. 5, 189. 1754". Flora of North America vol. 8. New York: Oxford University Press. pp. 43–146. Retrieved 9 January 2020.