''Malus'' ( or ) is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
of about 30–55
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
of small
deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...
trees or
shrubs in the family
Rosaceae, including the domesticated orchard
apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ancest ...
, crab apples,
wild apples, and rainberries.
The genus is
native
Native may refer to:
People
* Jus soli, citizenship by right of birth
* Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory
** Native Americans (disambiguation)
In arts and entert ...
to the
temperate zone of the
Northern Hemisphere.
Description
Apple trees are typically talI at maturity, with a dense, twiggy crown. The
leaves are long, alternate, simple, with a serrated margin. The
flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanis ...
s 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).
Many apples require
cross-pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, bird ...
between individuals by
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...
s (typically
bee
Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfami ...
s, which freely visit the flowers for both
nectar and
pollen); these are called self-sterile, so self-pollination is impossible, making pollinating insects essential.
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.
Several ''Malus'' species, including domestic apples,
hybridize freely.
The
fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...
is a globose
pome, varying in size from in diameter in most of the wild species, to in ''M. sylvestris sieversii'', 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
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...
s.
Subdivisions and species
About 42 to 55 species and natural hybrids are known, with about 25 from China, of which 15 are endemic. The genus ''Malus'' is subdivided into eight sections (six, with two added in 2006 and 2008). The genus ''
Docynia
''Docynia'' (栘𣐿属, ''yí yī shǔ'') is a genus of flowering trees, evergreen or semi-evergreen, in the family Rosaceae. The fruit is a pome. The tree is endemic to Southeast Asia, including Myanmar
Myanmar, ; UK pronunciations: U ...
'' has been shown to be nested within ''Malus'' in molecular phylogenies. The oldest fossils of the genus date to the
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...
(
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.
Natural hybrids
* ''
Malus × micromalus'' – midget crabapple
Fossil species
After
* ''Malus collardii'' Axelrod, North America (Idaho),
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...
* ''Malus kingiensis'' Budants, Kamchatka Peninsula, Russia, Eocene
* ''Malus florissantensis'' (Cockerell) MacGinitie
Green River Formation
The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very f ...
, North America (Colorado) Eocene
* ''Malus pseudocredneria'' (Cockerell) MacGinitie Green River Formation, North America (Colorado) Eocene
* ''Malus idahoensis'' R.W.Br. North America (Idaho),
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...
* ''Malus parahupehensis'' J.Hsu and R.W.Chaney
Shanwang, Shandong, China, Miocene
* ''Malus antiqua'' Doweld Romania,
Pliocene
* ''Malus pseudoangustifolia'' E.W.Berry North America (South Carolina),
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
Cultivation
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.
Some crabapples are used as
rootstocks for domestic apples to add beneficial characteristics. 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.
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.
Because of the plentiful blossoms and small fruit, crabapples are popular for use in
bonsai culture.
Cultivars
These cultivars have won the
Royal Horticultural Society's
Award of Garden Merit:-
*'Adirondack'
*'Butterball'
* 'Comtesse de Paris'
*'Evereste'
*'Jelly King'='Mattfru'
*'Laura'
*''
Malus × robusta'' 'Red Sentinel'
*'Sun Rival'
Other varieties are dealt with under their species names.
Toxicity
The seeds contain
cyanide
Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms.
In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...
compounds.
Uses
Crabapple fruit is not an important
crop
A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydropon ...
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 Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainland ...
n cultures, they are valued as a sour
condiment, sometimes eaten with salt and
chilli or
shrimp paste.
Some crabapple varieties are an exception to the reputation of being sour, and can be very sweet, such as the 'Chestnut' cultivar.
Crabapples are an excellent source of
pectin, and their
juice can be made into a ruby-coloured
preserve
The word preserve may refer to:
Common uses
* Fruit preserves, a type of sweet spread or condiment
* Nature reserve, an area of importance for wildlife, flora, fauna or other special interest, usually protected
Arts, entertainment, and medi ...
with a full, spicy flavour. A small percentage of crabapples in
cider makes a more interesting flavour.
As
Old English
Old English (, ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the early Middle Ages. It was brought to Great Britain by Anglo-Saxon settlers in the mid-5th ...
''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.
It is easier to cut when green; dry applewood is exceedingly difficult to carve by hand.
[ It is a good wood for cooking fires because it burns hot and slow, without producing much flame.][
]
Gallery
File:Apple blossom. Eastern Siberia.jpg, Apple blossom. Eastern Siberia
File:Crabapples.jpg, Ripe wild crab apples (''Malus sylvestris'')
File:Lee-Russell-Farm-Security-Administration-1939-Crab-Apples.jpg, Baskets of crab apples for sale in Connecticut in 1939
File:20071103Tradkrafta1.JPG, Trunk
References
External links
Germplasm Resources Information Network: ''Malus''
Flora of China: ''Malus''
a cooperative among Purdue University
Purdue University is a public land-grant research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and ...
, Rutgers University
Rutgers University (; RU), officially Rutgers, The State University of New Jersey, is a public land-grant research university consisting of four campuses in New Jersey. Chartered in 1766, Rutgers was originally called Queen's College, and was ...
, and the University of Illinois.
{{Authority control
Rosaceae genera
Plants used in bonsai
Fruit trees
Taxa named by Philip Miller