Pacific crab apple
Malus fusca (Raf) Schneid.
Pacific crab apple is a small tree or multi-stemmed shrub that grows up to 12 m tall. It is found along the coast, from sea level to mid elevations, on moist sites and along rivers (Parish et al. 1994). The species has no commercial uses and information about it is limited. Malus fusca possesses valuable polygenic resistance to fireblight (Erwinia amylovora) (Aldwinckle and Van Der Zwet 1979), an important disease on commercial apple varieties, as well as a high resistance to mildew (Podosphaera leucotricha) (Vujanic-Varga and Ognjanov 1988). As such, it is of interest for apple breeding. The hard, resilient wood was used by first peoples for making implements (Turner 1979). The apples, stored in water for preservation, were an important food. Some apple trees grew in carefully tended orchards. Imported apples were readily adopted and cultivated (Turner 1995).
The natural range of Pacific crab apple consists of a coastal belt from South Alaska to Northwest California. Somewhat less than half of the total range is located in British Columbia (Little 1976).
Distribution and Protected Areas – from Hamann et.al. 2005
In situ Conservation Status Summary – from Chourmouzis et.al. 2009
“Pacific crab apple occurs in coastal British Columbia, mainly in the CDF and CWH zones, with some extension into the ICH zone on the north coast. It is well protected in the CWH zone. While protection is low in both the ICH and CDF zones, Pacific crab apple is identified as a potential species of concern and is recommended for ground truthing only in the ICH zone. A comprehensive re-evaluation of protection status and needs for this species in the CDF zone is recommended prior to field verification in the zone.”
Ex situ collections
Ex situ collections are likely present in the form of germplasm collections for horticulture breeding programs (Paulin et al. 1983; Fischer 1994) but how extensive these are and how relevant to conservation of the native species as a whole, remains to be investigated.
The interval between good seed crops is two to four years (Banerjee et al. 2001).
Isozyme analysis has revealed large genetic differences between Pacific crab apple and the eastern North American apples, as well as between native and cultivated apples, indicating little gene flow from cultivated apples into native Malus (Dickson et al. 1991).
Resource management and seed transfer
No information available.