Mentha spicata × M. suaveolens (M.
× villosa var. alopecuroides (Hull)
Briq.) Garden Apple-mint
Account Summary
Introduction, neophyte, very rare.
1997; Wolfe-Murphy, S.A.; Colebrooke River, unspecified site.
Growth form and preferred habitats
M. × villosa is an extremely variable, rhizomatous, perennial, completely sterile hybrid between two widely cultivated mints, the introduced Spear Mint (M. spicata) and the perhaps partially native Round-leaved Mint (M. suaveolens). [See the species account on this webpage.] There is a history of taxonomic confusion associated with this hybrid thanks to its extreme variability, the extent of which is demonstrated by the fact that Crawley (2005) provides a synonymy with no less than seven alternative names. M. × villosa is so very variable, four varieties of it are recognised and named in the flora of B & I. Of these four, M. × villosa var. alopecuroides, which is definitely of garden origin, appears to be, and probably is, the most widespread form (Sell & Murrell 2009; R.M. Harley, in: Stace et al. 2015).
Unlike the other three taxonomic varieties, var. alopecuroides is a uniform hybrid, probably represented in B & I by a single clone. It has been known in Britain since at least the 18th century, but is frequently mistaken for M. suaveolens (R.M. Harley, in: Stace et al. 2015). In this variety, the stem has middle stem leaves 4-8 cm long, broadly ovate, sub-rotund or orbicular, softly hairy, margins serrate and with teeth large, patent (ie directed outwards, ± at 90°). There are punctate glands on both leaf surfaces that give the variety its sweet fragrance similar to Spear Mint. The inflorescence is robust, calyx 2 mm and the corolla is pink.
M. × villosa var. alopecuroides is, however, frequently confused with other forms of round-leaved mint, including M. spicata (Spear Mint) itself and, unsurprisingly, also with M. × rotundifolia (False Apple-mint), which is the hybrid between M. longifolia (Horse Mint), a European species not recorded in Britain (Stace 2019) and M. suaveolens.
Other forms of M. × villosa are usually more narrow-leaved than var. alopecuroides, with a generally oblong or oblong-ovate to lanceolate outline.
For this reason, and because the whole Mentha genus is difficult to unravel, largely due to an absence of genetic barriers to hybridisation, M. × villosa var. alopecuroides is certainly unevenly recorded throughout B & I and is very probably under-recorded in the wild.
Fermanagh occurrence
The solitary record of this mint hybrid listed above is from the typical 'rough grassland near water' habitat that so regularly provides the necessary conditions for sustained survival of garden escapes within this genus. This hybrid often forms small patches near water, but can also occur in drier sites, where it is generally associated with fly-tipping of garden waste or excess.
Irish occurrence
The Cat Alien Pl Ir indicates that this hybrid has been recorded in ten other Irish VCs (not including Fermanagh), seven of them with post-1980 records. It may be that Garden Apple-mint is becoming more popular with gardeners and cooks and could therefore perhaps be making more appearances in the wild than before, but the present state of knowledge does not support this contention. It merely indicates or reflects the need for more active recording of this rather difficult group of plants.
British occurrence
The hectad map in Stace et al. (2015) shows that M. × villosa is a very widespread hybrid throughout lowland Britain, and since var. alopecuroides is very commonly grown in gardens, it is by far the most frequently recorded variety of the four in the wild. The map shows M. × villosa throughout Britain from S to N, from the Channel Isles to Shetland. In Scotland, northwards of the Glasgow-Edinburgh conurbations, it quite quickly becomes somewhat confined to coastal areas. The map in Stace et al. (2015) contains records of M. × villosa from a total of 1,222 hectads in Britain. In Ireland, by comparison, the same map displays symbols from just 24 hectads.
As with other garden mints, this sterile hybrid is very vigorous, spreading rapidly in fertile cultivated ground by underground rhizomes and above ground stolons to form large colonies. It can thus quite quickly become invasive and outgrow the space allocated to it, resulting in excess material being dug out and dumped, sometimes illegally in waste ground or along roadsides or on riverbanks (K. Walker, in: Preston et al. 2002; R.M. Harley, in: Stace et al. 2015).
European and world occurrence
This hybrid mint is widely naturalised in mainland Europe.