Malus ioensis (Alph. Wood) Britt.

The Prairie Crab belongs to the complex centred on Malus coronaria, intergrading and possibly hybridizing with that species (Dickson 2015). It differs from both M. coronaria and M. angustifolia in its leaves being persistently downy beneath; the branchlets are also conspicuously hairy. Increased hairiness is a frequent character in the westernmost forms of Eastern North American trees (Bean 1981): this might correlate with a drier climate. M. ioensis has a more westerly distribution than these other species, centred on the Upper Mississippi Valley and extending well across the Great Plains (Dickson 2015; Kartesz 2015). Alphonso Wood’s epithet (originally published as Pyrus coronaria var. ioensis, in 1861) indicates the state of Iowa, where it is native. While polyploids have been reported (Dickson 2015) it has been suggested that this is primarily a diploid, sexual species (Fiala 1994).

It is chiefly grown for its flowers, scented and usefully late. In older specimens the attractively peeling bark can be a bonus, and it is capable of good orange-red autumn colour (Edwards & Marshall 2019; Lady Bird Johnson Wildflower Center 2020). The small, astringent fruits were made into jelly and dried for winter use by the Meskwaki, who also used some part of the plant as a smallpox treatment in the 19th Century (Moerman 2020). Early settlers east of the Appalachians also made use of this hardy, deep rooting tree, making preserves and cider (Yatskievych 2013).

As a more western species, Prairie Crab reached European cultivation much later than its close relatives, being introduced to Kew only in 1906 (Elwes & Henry 1912). Unselected examples remain uncommon. In Britain there are two older specimens at Westonbirt, Gloucestershire (Forestry England 2020) and The Tree Register (2020) records of trees 4 and 5 m tall in two private Kent gardens. In Ireland a tree at the National Botanic Gardens, Glasnevin planted in 1969 was measured at 5 m × 42 cm in 2012 (The Tree Register 2020). There are specimens of wild origin at Gothenburg Botanic Garden, Sweden, and Meise Botanic Garden, Belgium, from 1989 and 2010 accessions respectively (Gothenburg Botanical Garden 2020, Meise Botanic Garden 2020).

In North America too it is not often grown, except as its cultivars (Jacobson 1996). There are several specimens of Illinois provenance at the Morton Arboretum, IL, and young trees of both Illinois and Iowa provenance at the Arnold Arboretum, MA (Morton Arboretum 2020, Arnold Arboretum 2020). The American champion, within its natural range at Callaway, MO, is far from shrubby, with a stout, curving trunk and spreading branches (7 m × 99 cm in 2010 – American Forests 2020).

Like M. coronaria, M. ioensis is susceptible to rust, although it is very resistant to scab (Dirr 2009). Cedar-apple rust (Gymnosporangium juniperi-virginianae) has Juniperus virginiana as an alternate host, and the two species should be well separated in North American plantings.

Where M. ioensis and M. domestica meet, the hybrid M. × soulardii (q.v.) may arise.

Cultivars of Prairie Crab have been selected for more intensely pink petals, for fimbriate petals, and for semi- or fully-double flowers. Some are far more commonly grown than the unselected species.