Malva moschata L., Musk-mallow
Account Summary
Introduced, neophyte, a rare garden escape or 'wild-flower' seed plantation; probably only casual. European temperate, widely naturalised in N Europe, N America, Tasmania and New Zealand.
1950; MCM & D; Cornaleck, Upper Lough Erne.
July to November.
Growth form and preferred habitats
Musk-mallow is a medium tall (30-80 cm), herbaceous perennial bearing several erect, often purple-spotted stems from a thick, branching rootstock. The alternate leaves are rounded or kidney-shaped in outline, long stalked, 3-7-lobed and extremely variable, but often deeply cut into ± linear ultimate segments. Just below the flower calyx there are three small bracts, free for their entire length, which constitute an epicalyx, a useful identification feature for the genus.
M. moschata is a plant of dry or well-drained, sunny or lightly shaded, open or somewhat neglected grasslands, preferring, but not restricted to, light sandy loam soils of medium to high fertility. It can tolerate, or may actually require, moderate levels of disturbance, which helps to keep aggressive competition from taller and more vigorous species in check. Disturbance may take the form of light grazing or mowing on the margins of woodland and scrub, pastures, meadows, field margins, roadside verges, hedge banks, river banks, lake shores and grassy waste ground (Sinker et al. 1985; J.H.S. Cox, in: Preston et al. 2002; Sell & Murrrell 2018).
Variation
M. moschata is very variable, especially with respect to leaves and their degree of dissection, degree of stem and leaf hairiness, types of hairs and shade of flower colour. Despite this, most Floras do not distinguish varieties. However, Sell & Murrell (2018) have recently described no less than four varieties, two of which occur in only a few scattered locations. Of the other two more widespread forms, var. tenuifolia Guss. is probably the native plant throughout England, Wales and coastal Scotland, while var. undulata Sims was probably introduced in the last 40 years, mainly as a component of wild-flower seed (Sell & Murrell 2018).
Flowering reproduction
M. moschata produces attractive, 3-6 cm diameter, rose-pink or white, musk-scented flowers in clusters at the tops of stems from June to August. Flowers attract bees and other insect pollinators, but they can also self-fertilise. As in other members of the genus, the fruit is a dry schizocarp, ie it consists of a single ring of numerous (around 15) mericarp segments or nutlets, which split from one another when mature, each portion containing a single kidney-shaped seed (Stace 2010; Sell & Murrell 2018). Seed can remain viable in the soil for many years (Thompson et al. 1997).
Seed dispersal
While in Fermanagh and most of Ireland, M. moschata is only a rare, casual plant in the wild, the really interesting fact is that despite the lack of any obvious dispersal mechanism, the dry fruit mericarps which split off the disc-shaped schizocarp fruit, somehow manage to 'jump the garden wall'. The transport mechanism or vector enabling this is certainly not obvious. It is possible to imagine wind and rain-wash might together move the relatively large fruit segment and its contained seed a metre or so from the parent plant, but it would require a very exposed plant and a real gale or flood to move the propagule any greater distance right into the wild.
Considering seed dispersion in this genus, Ridley (1930, p. 361) relied mainly on cattle or other ungulates ingesting and transporting the fruit in their gut for his most probable mechanism. However, this solution would not apply in a garden setting. Ridley also mentioned work on the American Crow, Corvus brachyrhyncos, which is a major consumer of soft-fruit, yet which also eats many dry fruits and grains, including those of Malva species. Most seeds are probably destroyed by digestion, but some might survive and appear in the bird's pellets.
Does anyone know of a bird taking an interest in Mallow fruits in B & I, thus serving as an occasional seed vector? The only other vector the current author can suggest is human, possibly transporting the fruit unknowingly in mud on boots, trouser bottoms, tyres, or amongst discarded garden rubbish. I await with interest any helpful observations throwing light on the mystery of Malva dispersal.
Fermanagh occurrence
In the Revised Typescript Flora, Meikle et al. (1975) noted that Musk-mallow was not uncommon in Fermanagh gardens. Their solitary 1950 record at Cornaleck on the shore of Upper Lough Erne (not given in the 1951 Typescript Flora) was of a white-flowered garden form. Although it is a perennial, none of the plants at four of the five recent additional stations, all recorded by RHN, has persisted for long. They are also assumed to be garden escapes, although apparently M. moschata is now sometimes (regularly) associated with wild-flower seed mixtures (often of imported origin), increasingly sown in both public amenity areas and in garden settings. We are not as yet aware of any such source of Musk-mallow in Fermanagh.
The remaining details of the five later Fermanagh stations are: roadside on the Enniskillen-Belfast road near Boyhill, 1 July 1997;RHN; waste ground, Enniskillen town, 22 November 1998; RHN; waste ground, Drumawill, Sligo Road, Enniskillen, 11 October 2003; RHN; near farm yard, Cam, 1.5 km W of Corraslough Point, Upper Lough Erne, 17 August 2004; RHN; and by wall on N side of Mill Lough near Ballanaleck, 13 October 2010; RHN.
British occurrence
In England, Wales and S Scotland, M. moschata is a common and widespread perennial of lowland grassy places, generally regarded as native. In Scotland, north of a line between Girvan and Berwick-upon-Tweed, it is increasingly rare and is considered an escaped garden introduction (J.H.S. Cox, in: Preston et al. 2002).
Irish occurrence
In Ireland, by contrast, M. moschata is not usually a persistent plant. Nowadays it is recognised as an alien introduction, generally of garden origin (Reynolds 2002). In the mid-west of the island, where it typically is a rare roadside occurrence, the authors of the Flora of Connemara and the Burren commented, "scarcely more than a casual; it is only in SE Ireland that this species is firmly established". (Webb & Scannell 1983).The longest known persistence of any Musk-mallow colony in the wild in N Ireland is approximately 40 years, which happened along the banks of the Crumlin River near Lough Neagh, Co Antrim (H39) (Harron 1986; Hackney et al. 1992).
European and world occurrence
M. moschata originates from the Mediterranean region and probably parts of C Europe from England and Poland southwards (Tutin et al. 1968). It is widely cultivated in gardens and has spread well beyond its area of natural distribution to S Scandinavia, N Africa, N America, New Zealand and Tasmania (Hultén & Fries 1986, Map 1304).
Threats
None.