The World of Apples

Wild apples

Malus fusca (Raf.) Raf.

Oregon crabapple; Pacific crabapple; Western crabapple

Description

Malus fusca is a tree or large shrub, usually 5 to 10 m tall and occasionally 20 m, with bark that is smooth when young and becomes scaly and deeply fissured. Its leaves are ovate to lanceolate, 3–9 cm long, unlobed or three-lobed. The flowers are small, 1.5–2 cm across, white or sometimes pink, with white anthers and usually three hairless styles. The fruit is yellow to purplish red, oblong and only 6–10 mm across, sometimes 13 mm, and its sepals usually fall before it ripens. It has 34 chromosomes in its body cells1. It grows slowly and lives long for an apple, 100 to 150 years2.

In its native range it flowers from April to early July and fruits from June to November1.

Range and habitat

The Oregon crab apple grows along the Pacific coast from Alaska through British Columbia, Washington and Oregon to California1,3, from the Cascades westward and often by the sea2. It is a plant of moist, open places: open Sitka spruce forest, forest edges and clearings, the edges of beaches, sea cliffs, swamps, bogs and brackish marshes, from sea level to 600 m. It tolerates occasional exposure to salt water1. The IUCN Red List assessed it in 2014 as Least Concern, with a stable population4.

Uses

The fruit is tart but edible, and grows sweeter with keeping1. Indigenous peoples throughout its range ate it and preserved it in various ways, and made tools from its hard wood, among them seal spears, digging sticks and splitting wedges2. Western coastal peoples prepared its bark as a medicine1. The botanical explorers Archibald Menzies and David Douglas knew it, Rafinesque first named it, as a Pyrus, in 1830, and Douglas introduced it to Britain in the 1830s2.

Relationship to the cultivated apple

The Oregon crab apple stands apart from the apples of eastern North America. Elizabeth Dickson found it closer, in form and in its lineage, to Asian species1, and a 2015 review describes it as apparently more closely related to several Chinese species than to the other three North American species5. In Oregon and Washington it crosses with the orchard apple; the hybrid is named Malus × dawsoniana1.

Where the sources disagree

  • Its relatives. Most taxonomists have looked for its relatives among East Asian apples such as Malus kansuensis, but molecular studies have not given a consistent picture2. In a 2017 genome study it grouped with the other North American species, closest to the pear6.
  • Authority. Plants of the World Online cites the name as Malus fusca (Raf.) Raf.3; the Flora of North America and Trees and Shrubs Online give the combination to C. K. Schneider1,2.

Sources

  1. Malus fusca, Flora of North America vol. 9, Elizabeth E. Dickson, Flora of North America, eFloras.org. Supports: the description (trees or shrubs 5–10(–20) m, bark scaly and fissured with age, leaves unlobed or 3-lobed, flowers 15–20 mm, white or pink, anthers white, 3 glabrous styles, pome yellow to purplish red, oblong, 6–10(–13) mm, sepals deciduous, 2n = 34); flowering April–early July and fruiting June–November; habitats and elevation 0–600 m; British Columbia, Alaska, California, Oregon and Washington; tolerance of salt water; edible, tart fruit sweetening with time; bark used as medicine by western coastal Native Americans; closer to Asian species than to eastern North American ones (Dickson 1995); hybrid with M. domestica in Oregon and Washington, M. × dawsoniana; authority given as (Rafinesque) C. K. Schneider; the common names.
  2. Malus fusca, Julian Sutton and Nick Dunn, Trees and Shrubs Online (International Dendrology Society), 2021. Supports: the name given as Malus fusca (Raf.) Schneid.; range far to the west of the other North American species; often coastal, from the Cascades west; a wetland plant with some salt tolerance; slow-growing and long-lived for an apple, 100–150 years; first named as a Pyrus by Rafinesque in 1830; known to Menzies and Douglas; introduced to Britain by Douglas in the 1830s; fruit eaten and preserved by indigenous peoples, who used the hard wood for tools such as seal spears, digging sticks and wedges; relatives sought among East Asian species such as M. kansuensis, with no consistent picture from molecular studies.
  3. Malus fusca (Raf.) Raf., Plants of the World Online, Royal Botanic Gardens, Kew. Supports: accepted name with the authority (Raf.) Raf.; native range "Alaska to California"; Sinomalus fusca among the synonyms.
  4. Malus fusca, The IUCN Red List of Threatened Species 2016: e.T61855167A61855173, L. Rhodes and N. Maxted, 2016. Supports: Least Concern, assessed 1 July 2014; population stable; native to Canada (British Columbia) and the United States (Alaska, California, Oregon, Washington); forest, shrubland and inland wetland habitats; the common name Oregon crab apple.
  5. The vulnerability of US apple (Malus) genetic resources, Gayle M. Volk and others, Genetic Resources and Crop Evolution 62: 765–794; USDA GRIN, 2015. Supports: M. fusca appearing more closely related to several Chinese species than to the other three North American species.
  6. Genome re-sequencing reveals the history of apple and supports a two-stage model for fruit enlargement, Naibin Duan and others, Nature Communications 8: 249, 2017. Supports: the North American species, M. fusca among them, placed closest to pear in the phylogenetic tree.