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Sedum is a large genus of flowering plants in the family Crassulaceae, members of which are commonly known as stonecrops. The genus has been described as containing up to 600 species, subsequently reduced to 400–500. They are leaf succulents found primarily in the Northern Hemisphere, but extending into the southern hemisphere in Africa and South America. The plants vary from annual and creeping herbs to shrubs. The plants have water-storing leaves. The flowers usually have five petals, seldom four or six. There are typically twice as many stamens as petals. Various species formerly classified as Sedum are now in the segregate genera Hylotelephium and Rhodiola.

Sedum
Biting stonecrop close 800.jpg
Biting stonecrop (Sedum acre)
Scientific classification e
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Order: Saxifragales
Family: Crassulaceae
Subfamily: Sempervivoideae
Genus: Sedum
L.[1]
Type species
Sedum acre L.
Subgenus
  • Gormania
  • Sedum
Synonyms

Well-known European species of Sedum are Sedum acre, Sedum album, Sedum dasyphyllum, Sedum reflexum (also known as Sedum rupestre) and Sedum hispanicum.

DescriptionEdit

Sedum is a genus that includes annual, biennial, and perennial herbs. They are characterised by succulent leaves and stems.[2] The extent of morphological diversity and homoplasy make it impossible to characterise Sedum phenotypicaly.[3]

TaxonomyEdit

Sedum was first formally described by Linnaeus in 1753, with 16 species, and hence bears his name as the botanical authority (L.).[4] Of the genera encompassed by the Crassulaceae (stonecrop) family, Sedum is the most species rich, the most morphologically diverse and most complex taxonomically. Of the three subfamilies of the Crassulaceae, Sedum is placed in the subfamily Sempervivoideae. Although molecular phylogeny research has greatly reduced the genus, from about 600[5] to 420–470 species,[6] it still constitutes a third of the family and is polyphyletic.

The Crassulaceae clades are alocated to tribes, as follows:[7]

Clades and tribes within Sempervivoideae
Clade Tribe
Hylotelephium Telephieae
Rhodiola Umbiliceae
Sempervivum Semperviveae
Aeonium Aeonieae
Acre Sedeae
Leucosedum
Note

Clades containing Sedum, shown in blue

Species allocated to Sedum are found within four of the six separate Crassulceae clades in the Sempervivoideae (Acre, Leucosedum, Aeonium and Sempervivum), while other distinct genera appear to be nested within Sedum. However the number of species found outside of the first two clades (Tribe Sedeae) are only a small fraction of the whole genus. Therefore the current circumscription, which is somewhat artificial and catch-all must be considered unstable.[8] The relationships between the tribes of Sempervivoideae is shown in the cladogram.

Cladogram of Sempervivoideae tribes[7]
Sempervivoideae

Telephieae

Umbilicieae

Semperviveae

Aeonieae

Sedeae (Leucosedum+Acre)

There are now thought to be approximately 55 European species. Sedum demonstrates a wide variation in chromosome numbers, and polyploidy is common. Chromosome number is considered an important taxonomic feature.[9]

SubdivisionEdit

Various attempts have been made to subdivide this large genus, in addition to segregating separate genera, including creation of informal groups, sections, series and subgenera. Gray (1821) divided the 13 species known in Britain at that time into five sections:[10]

  • Rhodiola
  • Telephium
  • Sedum
  • (unamed)
  • Aizoon

Berger (1930) defined 22 subdivisions, which he called Reihe (series). Some later authors have added other series, and combined some of the series into groups.[8][2]

Sections and series include:[8]

  • Alsenifolia
  • Caerulea
  • Monanthoidea
  • Caerulea
  • Rupestria
  • Telephium

Later authors have recognised two subgenera, Gormania and Sedum.[8]

  • Gormania: (Britton) Clausen. 110 species from Sempervivum, Aeonium and Leucosedum clades, from Europe and North America.
  • Sedum: 320 species from Acre clade, from Asia and the Americas.

Nikulin and colleagues (2016) have recommended that, given the monophyly of Aeonieae and Semperviveae, species of Sedum outside of the tribe Sedeae (all in subgenus Gormania) be removed from the genus and reallocated. However this does not resolve the problem of other genera embedded within Sedum, in Sedeae.[8]

CladesEdit

Species and series include[7]

Subgenus GormaniaEdit
Semperviveae
  • S. series Rupestria (Eurasia)
  • S. assyriacum (Near East)
  • S. mooneyi M.Gilbert (NE Africa)

Of about 80 Eurasian species, series Rupestria forms a distinct monophyletic group of about ten taxa, which some authors have considered a separate genus, Petrosedum.[11][12][13] It was series 20 in Berger's classification. Native to Europe it has escaped cultivation and become naturalized in North America.[14]

Aeonieae (N Africa)
  • S. series Pubescens
  • S. series Caerulea
  • S. series Monanthoidea

Embedded within series Monanthoidea are three Macaronesian segregate genera, Aichryson, Monanthes and Aeonium.[7]

Sedeae - Leucosedum (Europe/Mediterranean/Near East/Central Asia)

Embedded within the Leucosedum clade are the following genera: Rosularia, Prometheum, Sedella and Dudleya.[7]

Subgenus SedumEdit
Sedeae - Acre (Asia/Europe/Macronesia/N. America)
  • S. farinosum Lowe (Macaronesia)
  • S. furfuraceum Moran (N. America)
  • S. hemsleanum Rose (N. America)
  • S. series Macaronesica (Macaronesia)
  • S. oaxacanum Rose (N. America)
  • S. obcordatum R.T. Clausen (N. America)
  • S. section Pachysedum (N. America)
  • S. sexangulare L. (Europe)
  • S. ternatum Michx. (N. America)

Embedded within the Acre clade are the following genera: Villadia, Lenophyllum, Graptopetalum, Thompsonella, Echeveria and Pachyphytum.[7]

List of selected speciesEdit

Distribution and habitatEdit

Distributed in mainly in temperate to subtropical climates the Northern hemisphere, extending to the Southern hemisphere in Africa and South America,[6] being most diverse in the Mediterranean,[15] Central America, Himalayas, and East Asia.[2]

EcologyEdit

Sedum species are used as food plants by the larvae of some Lepidoptera species including the grey chi moth. In particular, Sedum spathulifolium is the host plant of the endangered San Bruno elfin butterfly of San Mateo County, California.[citation needed] Sedum lanceolatum is the host plant of the more common Parnassius smintheus found in the Rocky Mountains.[16] As well as Sedum spathulifolium, many other species of Sedum serve the environmental role of host plants for butterflies. For example, the butterfly Callophrys xami uses several species of Sedum, such as Sedum allantoides, for suitable host plants.[17][18]

UsesEdit

OrnamentalEdit

Many sedums are cultivated as ornamental garden plants, due to their interesting and attractive appearance and hardiness. The various species differ in their requirements; some are cold-hardy but do not tolerate heat, some require heat but do not tolerate cold.

Numerous hybrid cultivars have been developed, of which the following have gained the Royal Horticultural Society's Award of Garden Merit:[a]

  • 'Herbstfreude' ('Autumn Joy')[19]
  • 'Bertram Anderson'[20]
  • 'Matrona'[21]
  • 'Ruby Glow'[22]

As foodEdit

The leaves of most stonecrops are edible,[23] excepting Sedum rubrotinctum, although toxicity has also been reported in some other species.[24]

Sedum reflexum, known as "prickmadam", "stone orpine", or "crooked yellow stonecrop", is occasionally used as a salad leaf or herb in Europe, including the United Kingdom.[25] It has a slightly astringent sour taste.

Sedum divergens, known as "spreading stonecrop", was eaten by First Nations people in northwest British Columbia. The plant is used as a salad herb by the Haida and the Nisga'a people. It is common in the Nass Valley of British Columbia.[26]

Biting stonecrop (Sedum acre) contains high quantities of piperidine alkaloids (namely (+)-sedridine, (−)-sedamine, sedinone and isopelletierine), which give it a sharp, peppery, acrid taste and make it somewhat toxic.

RoofingEdit

Sedum can be used to provide a roof covering in green roofs,[27][28] where they are preferred to grasses.[29] Ford's Dearborn Truck Plant's living roof has 454,000 square feet (42,200 m2) of sedum[30]. Rolls-Royce Motor Cars plant in Goodwood, England, has a 242,000 square feet (22,500 m2) roof complex covered in Sedum, the largest in the United Kingdom.[31] Nintendo of America's roof is covered in some 75,000 square feet (7,000 m2) of Sedum.[32] The Javits Center in New York City is covered with 292,000 square feet (27,100 m2) of Sedum.[33]

GalleryEdit

NotesEdit

  1. ^ Hylotelephium often considered a separate genus

ReferencesEdit

  1. ^ GRIN 2019.
  2. ^ a b c Ito et al 2017.
  3. ^ Nikulin & Gontcharov 2017.
  4. ^ Hart & Jarvis 1993.
  5. ^ Ohba 1977.
  6. ^ a b Fu et al 2004.
  7. ^ a b c d e f Thiede & Eggli 2007.
  8. ^ a b c d e Nikulin et al 2016.
  9. ^ Hart 1985.
  10. ^ Gray 1821.
  11. ^ van Ham et al 1994.
  12. ^ Gallo 2017.
  13. ^ Gallo 2017a.
  14. ^ Gallo & Zika 2014.
  15. ^ Hart 1997.
  16. ^ Doyle 2011.
  17. ^ Opler 1999.
  18. ^ Ziegler & Escalante 1964.
  19. ^ RHS 2019, Hylotelephium 'Herbstfreude'
  20. ^ RHS 2019, Hylotelephium 'Bertram Anderson'
  21. ^ RHS 2019, Hylotelephium 'Matrona'
  22. ^ RHS 2019, Hylotelephium 'Ruby Glow'
  23. ^ Pojar & MacKinnon 2004, p. 157.
  24. ^ NCSU 2016.
  25. ^ PFAF 2012.
  26. ^ Pojar & MacKinnon 2004, p. 156.
  27. ^ NCSU 2019.
  28. ^ Monterusso et al 2005.
  29. ^ Kalinowski 2009.
  30. ^ "Ford Motor Company's River Rouge Truck Plant".
  31. ^ "Rolls-Royce - Made in Sussex". Sussex Life. October 25, 2010. Retrieved 2010-11-19.
  32. ^ Stephen Totilo (August 25, 2011). "The Coolest Things in Nintendo's American Headquarters (And One Uncool Thing)". Kotaku.
  33. ^ "NYREJ Project of the Month: FXFOWLE, Epstein and Tishman complete renovation/ expansion of $465 million Jacob K. Javits Convention Center". New York Real Estate Journal. December 9, 2013.

BibliographyEdit

Books and thesesEdit

ArticlesEdit

WebsitesEdit

External linksEdit