Sidalcea Explained

Sidalcea is a genus (approx. 25 species^[1]) of the botanical family Malvaceae. It contains several species of flowering plants known generally as checkerblooms or checkermallows, or prairie mallows in the United Kingdom. They can be annuals or perennials, some rhizomatous. They are native to West and Central North America.

In mid- to late summer the clumps of toothed basal leaves produce erect flowering stems, with 5-petalled mallow-type flowers in terminal racemes, in shades of pink, white and purple.^[2]

Sidalcea is generally diploid (2n = 20), but polyploidy (4n, 6n) also occurs.^[3]

Annuality appears to have evolved multiple times (4+) within this genus, although an ancestral annual state with annual paraphyly is also possible. Further, evolution rates within annual Sidalcea lineages appear to be faster than those of perennial lineages, at least when examining nuclear ribosomal DNA (internal and external transcribed spacer regions).^[1]

Selected species:

(A = annual, P = perennial^[3])

• Sidalcea asprella^[3] (P)
• Sidalcea calycosa – annual checkerbloom (A)
• Sidalcea campestris – meadow checkermallow (P)
• Sidalcea candida – white checkerbloom (P)
• Sidalcea covillei – Owens Valley sidalcea (P)
• Sidalcea cusickii – Cusick's checkermallow (P)
• Sidalcea diploscypha – fringed checkerbloom (A)
• Sidalcea glaucescens – waxy checkerbloom (P)
• Sidalcea gigantea^[3] (P)
• Sidalcea hartwegii – valley checkerbloom (A)
• Sidalcea hendersonii – Henderson's checkermallow (P)
• Sidalcea hickmanii – chaparral checkerbloom (P)
• Sidalcea hirsuta – hairy checkerbloom (A)
• Sidalcea hirtipes^[3] - hairy-stemmed checker-mallow^[4] (P)
• Sidalcea keckii – Keck's checkerbloom (A)
• Sidalcea malachroides – mapleleaf checkerbloom (P)
• Sidalcea malviflora – dwarf checkerbloom
• Sidalcea multifida^[3] (P)
• Sidalcea nelsoniana – Nelson's checkermallow (threatened)
• Sidalcea neomexicana – Salt Spring checkerbloom (P)
• Sidalcea oregana – Oregon checkerbloom (miniature hollyhock)
  • Sidalcea oregana var. calva – Wenatchee Mountains checkermallow
• Sidalcea pedata – birdfooted checkerbloom, Big Bear checkerbloom (P)
• Sidalcea ranunculacea – marsh checkerbloom
• Sidalcea reptans – Sierra checkerbloom
• Sidalcea robusta – Butte County checkerbloom (P)
• Sidalcea stipularis – Scadden Flat checkerbloom (P)
• Sidalcea virgata (P)

Garden cultivars are hybrids between S. candida and S. malviflora. The perennial cultivars "Elsie Heugh",^[5] 'Oberon'^[6] and "William Smith"^[7] have gained the Royal Horticultural Society's Award of Garden Merit.^[8]

References

• Book: Pink, A. . Gardening for the Million. 2004 . Project Gutenberg Literary Archive Foundation.
• US Fish and Wildlife page on Sidalcea nelsoniana.

External links

• • List of Sidalcea species in California at Calflora

Notes and References

1. Andreasen. K.. Baldwin. B. G.. 2001-06-01. Unequal evolutionary rates between annual and perennial lineages of checker mallows (Sidalcea, Malvaceae): evidence from 18S-26S rDNA internal and external transcribed spacers. Molecular Biology and Evolution. 18. 6. 936–944. 0737-4038. 11371581. 10.1093/oxfordjournals.molbev.a003894. free.
2. Book: RHS A-Z encyclopedia of garden plants. 2008. Dorling Kindersley. United Kingdom. 978-1405332965. 1136.
3. Andreasen. Katarina. Baldwin. Bruce G.. 2003-03-01. Reexamination of relationships, habital evolution, and phylogeography of checker mallows (Sidalcea; Malvaceae) based on molecular phylogenetic data. American Journal of Botany. en. 90. 3. 436–444. 10.3732/ajb.90.3.436. 0002-9122. 21659137.
4. Web site: Sidalcea hirtipes C.L. Hitchc. hairy-stemmed checker-mallow. Washington State Department of Natural Resources. Hitchcock 1957 referenced. March 3, 2016.
5. Web site: RHS Plant Selector Sidalcea 'Elsie Heugh' AGM / RHS Gardening . Apps.rhs.org.uk . 2021-03-09.
6. Web site: Sidalcea 'Oberon' . RHS . 5 March 2021.
7. Web site: RHS Plant Selector Sidalcea 'William Smith' AGM / RHS Gardening . Apps.rhs.org.uk . 2021-03-09.
8. Web site: AGM Plants - Ornamental . July 2017 . 97 . Royal Horticultural Society . 11 November 2018.