Malus
Temporal range: Eocene–Recent
Malus ‘Purple Prince'[1]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Rosaceae
Subfamily: Amygdaloideae
Tribe: Maleae
Subtribe: Malinae
Genus: Malus
Mill.
Type species
Malus sylvestris
Mill. (1768)
Species

See text

Synonyms[2]
  • Chloromeles (Decne.) Decne. (1882)
  • Docynia Decne. (1874)
  • Eriolobus (Ser.) M.Roem.(1847)
  • Prameles Rushforth (2018)
  • Sinomalus Koidz. (1932)
  • × Tormimalus Holub (1998)

Malus (/ˈmləs/[3] or /ˈmæləs/) is a genus of about 32–57 species[4] of small deciduous trees or shrubs in the family Rosaceae, including the domesticated orchard apple, crab apples and wild apples.

The genus is native to the temperate zone of the Northern Hemisphere.

Description

Flowering crabapple blooms

Apple trees are typically 4–12 metres (13–39 feet) talI at maturity, with a dense, twiggy crown. The leaves are 3–10 centimetres (1+14–4 inches) long, alternate, simple, with a serrated margin. The flowers are borne in corymbs, and have five petals, which may be white, pink, or red, and are perfect, with usually red stamens that produce copious pollen, and a half-inferior ovary; flowering occurs in the spring after 50–80 growing degree days (varying greatly according to subspecies and cultivar).[citation needed]

Many apples require cross-pollination between individuals by insects (typically bees, which freely visit the flowers for both nectar and pollen); these are called self-sterile, so self-pollination is impossible, making pollinating insects essential.[citation needed]

A number of cultivars are self-pollinating, such as 'Granny Smith' and 'Golden Delicious', but are considerably fewer in number compared to their cross-pollination dependent counterparts.[citation needed]

Several Malus species, including domestic apples, hybridize freely.[5]

The fruit is a globose pome, varying in size from 1–4 cm (121+12 in) in diameter in most of the wild species, to 6 cm (2+14 in) in M. sylvestris sieversii, 8 cm (3 in) in M. domestica, and even larger in certain cultivated orchard apples. The centre of the fruit contains five carpels arranged star-like, each containing one or two seeds.[citation needed]

Subdivisions and species

36 species and 4 hybrids are accepted.[2] The genus Malus is subdivided into eight sections (six, with two added in 2006 and 2008).[citation needed] The oldest fossils of the genus date to the Eocene (Lutetian), which are leaves belonging to the species Malus collardii and Malus kingiensis from western North America (Idaho) and the Russian Far East (Kamchatka), respectively.[6]

Species

36 species and four natural hybrids are accepted:[2]

Hybrids

Formerly placed here

Selected artificial hybrids

Fossil species

After[6]

Cultivation

See also: Fruit tree pollination

'Evereste' fruits
Crabapple bonsai tree taken in August

Crabapples are popular as compact ornamental trees, providing blossom in spring and colourful fruit in autumn. The fruits often persist throughout winter. Numerous hybrid cultivars have been selected.[citation needed]

Some crabapples are used as rootstocks for domestic apples to add beneficial characteristics.[7] For example, the rootstocks of Malus baccata varieties are used to give additional cold hardiness to the combined plants for orchards in cold northern areas.[8]

They are also used as pollinizers in apple orchards. Varieties of crabapple are selected to bloom contemporaneously with the apple variety in an orchard planting, and the crabs are planted every sixth or seventh tree, or limbs of a crab tree are grafted onto some of the apple trees. In emergencies, a bucket or drum bouquet of crabapple flowering branches is placed near the beehives as orchard pollenizers.[citation needed]

Because of the plentiful blossoms and small fruit, crabapples are popular for use in bonsai culture.[9][10][11]

Cultivars

These cultivars have won the Royal Horticultural Society's Award of Garden Merit:-[12]

Other varieties are dealt with under their species names.

Toxicity

The seeds contain cyanide compounds.[21]

Uses

Crabapple fruit is not an important crop in most areas, being extremely sour due to malic acid (which like the genus derives from the Latin name mālum), and in some species woody, so is rarely eaten raw. In some Southeast Asian cultures, they are valued as a sour condiment, sometimes eaten with salt and chilli or shrimp paste.[citation needed]

Some crabapple varieties are an exception to the reputation of being sour, and can be very sweet, such as the 'Chestnut' cultivar.[22]

Crabapples are an excellent source of pectin, and their juice can be made into a ruby-coloured preserve with a full, spicy flavour.[23] A small percentage of crabapples in cider makes a more interesting flavour.[24] As Old English Wergulu, the crab apple is one of the nine plants invoked in the pagan Anglo-Saxon Nine Herbs Charm, recorded in the 10th century.

Applewood gives off a pleasant scent when burned, and smoke from an applewood fire gives an excellent flavour to smoked foods.[25] It is easier to cut when green; dry applewood is exceedingly difficult to carve by hand.[25] It is a good wood for cooking fires because it burns hot and slow, without producing much flame.[25] Applewood is used to make handles of hand saws; in the early 1900s 2,000,000 board feet of applewood were used annually for this purpose.[26]

Gallery

References

  1. ^ Cirrus Digital Purple Prince Crabapple
  2. ^ a b c "Malus Mill". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 17 December 2023.
  3. ^ Sunset Western Garden Book, 1995:606–607
  4. ^ Phipps, James B.; Robertson, Kenneth R.; Smith, Paul G.; Rohrer, Joseph R. (1990). "A checklist of the subfamily Maloideae (Rosaceae)". Can. J. Bot. 68 (10): 2209–2269. doi:10.1139/b90-288.
  5. ^ Ken Wilson and D.C. Elfving. "Crabapple Pollenizers for Apples". Ontario Ministry of Agriculture and Food. Retrieved 12 Sep 2013.
  6. ^ a b Liu, Bin‐Bin; Ren, Chen; Kwak, Myounghai; Hodel, Richard G.J.; Xu, Chao; He, Jian; Zhou, Wen‐Bin; Huang, Chien‐Hsun; Ma, Hong; Qian, Guan‐Ze; Hong, De‐Yuan; Wen, Jun (May 2022). "Phylogenomic conflict analyses in the apple genus Malus s.l. reveal widespread hybridization and allopolyploidy driving diversification, with insights into the complex biogeographic history in the Northern Hemisphere". Journal of Integrative Plant Biology. 64 (5): 1020–1043. doi:10.1111/jipb.13246. ISSN 1672-9072. PMID 35274452. S2CID 247384781.
  7. ^ Apple Tree Rootstocks Ecogardening Factsheet #21, Summer 1999
  8. ^ Alaska Department of Natural Resources [https://web.archive.org/web/20080719050542/http://www.dnr.state.ak.us/ag/21Applerootstocks.pdf Archived 2008-07-19 at the Wayback Machine
  9. ^ Biel, John. "Collecting and Training Crab Apples | American Bonsai Society". www.absbonsai.org. American Bonsai Society. Archived from the original on 3 July 2016. Retrieved 2 August 2016.
  10. ^ "Crabapple (Malus) - Bonsai Empire". www.bonsaiempire.com. Retrieved 2 August 2016.
  11. ^ Walston, Brent. "Crabapples for Bonsai". evergreengardenworks.com. Retrieved 2 August 2016.
  12. ^ "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 63. Retrieved 2 April 2018.
  13. ^ "RHS Plantfinder - Malus 'Adirondack'". Retrieved 25 March 2018.
  14. ^ "RHS Plantfinder - Malus 'Butterball'". Retrieved 25 March 2018.
  15. ^ "Malus 'Comtesse de Paris'". RHS. Retrieved 6 January 2021.
  16. ^ "RHS Plantfinder -Malus 'Evereste'". Retrieved 25 March 2018.
  17. ^ "RHS Plantfinder - Malus Jelly King = 'Mattfru'". Retrieved 25 March 2018.
  18. ^ "RHS Plantfinder - Malus 'Laura'". Retrieved 25 March 2018.
  19. ^ "RHS Plantfinder - Malus × robusta 'Red Sentinel'". Retrieved 25 March 2018.
  20. ^ "RHS Plantfinder - Malus 'Sun Rival'". Retrieved 25 March 2018.
  21. ^ The Complete Guide to Edible Wild Plants. United States Department of the Army. New York: Skyhorse Publishing. 2009. p. 113. ISBN 978-1-60239-692-0. OCLC 277203364.((cite book)): CS1 maint: others (link)
  22. ^ "The Growing Guide". Stark Bro's Nurseries & Orchards Co. Archived from the original on 2014-07-26.
  23. ^ Rombauer, I.; Becker, M. R.; Becker, E. (2002) [2002]. All About Canning & Preserving (The Joy of Cooking series). New York: Scribner. p. 72. ISBN 0-7432-1502-8.
  24. ^ "The Science of Cidermaking". Andrew Lea. Retrieved November 14, 2013.
  25. ^ a b c Fraser, Anna (22 August 2005). "Properties of different trees as firewood". Retrieved 17 July 2008.
  26. ^ Burks, Jeff (2015). "Woods Used in Saw Handles". Lost Art Press, Traditional Hand-tool Skills. blog.lostartpress.com.