Malva neglecta Wallr., Dwarf Mallow
Account Summary
Archaeophyte, casual, probably extinct. European temperate, widely naturalised beyond its native range in Europe and introduced in N America and Australia.
1900; West, W.; Levally House, 1 km SE of Roosky.
A habitually self-pollinating annual, Dwarf Mallow grows in the same sort of dry, sandy or gravelly, ecologically open situations which other Malva species typically frequent in B & I, either on inland waste ground or disturbed grassy roadsides, often near habitation, as well as in open, coastal sites.
It is an archaeophyte dating from Roman times in Britain and although it is fairly well established in a few places further south in Ireland, eg around Galway Bay and in the Dublin-Wicklow areas, it is a merely casual introduction in the rest of Ireland. Throughout Ireland, the majority of the widely scattered stations are coastal, the plant often growing along the drift-line (Webb & Scannell 1983; New Atlas).
M. neglecta has not been seen in Fermanagh for over 50 years and we therefore regard it as locally extinct. The only record in the Fermanagh Flora Database additional to the first listed above is: on a rubbish tip, Enniskillen town, 1947, MCM & D.
In N Ireland, the only recent record of M. neglecta was made around 1999 by Ian McNeill, on waste ground on the coast at Portstewart, Co Londonderry (H40) (Reynolds 2002).
In Britain, Dwarf Mallow is widespread, frequent and established in S England, but elsewhere it again is mainly a casual species, decreasing northwards and becoming increasingly confined to the E coast, although the New Atlas map shows it stretches north beyond Inverness.
Growth form and preferred habitats
A colourful, if rather untidy, straggling, decumbent or nearly erect, 45-90(-150) cm tall, variably hairy, introduced garden perennial or biennial, M. sylvestris has palmate stem leaves, each with 5-7 deep lobes, indented about a third the way to their stalked base.
Like most mallow species in B & I, M. sylvestris tends to occupy fairly dry, even droughted, well-drained sites. It prefers moderately fertile or nutrient-enriched soils and sunny or only lightly shaded situations on grassy waste ground, hedge banks, field margins and the like, often near houses or ruins (J.H.S. Cox, in: Preston et al. 2002). It has a deep, thick, woody taproot which allows it to tolerate dry soils and drought remarkably well, considering the large amount of aerial tissue it usually supports.
Mallows are not very competitive and they all tolerate or appreciate some habitat disturbance, helping to keep the ground open and limiting competition. Usually this involves grazing, trampling or mowing, but in this specific instance, on account of the proximity of many of our Fermanagh records to lakeshores, seasonal flooding may help create suitable conditions.
Flowering reproduction
Flowers are produced from June to September, either singly or in small clusters in the leaf axils at the tip of the stem, forming an irregular raceme. Only one or two flowers are in bloom at any time. Individual flowers have five connivent sepals that fail to enlarge in fruit, so they never overlap. The five notched petals, 20-30 mm long, are 2-4 times the size of the sepals and are bright pinkish-purple with darker stripes. The calyx is furnished with an epicalyx of three bracteoles beneath it. Pollination is by bees and other insects searching for nectar; the fruit is a schizocarp composed of a single ring of wedge-shaped carpels around a central axis that eventually splits into separate mericarps or nutlets, each containing a single seed (Sell & Murrell 2018). Other than this, there is no special dispersal mechanism (see below).
Fruit dispersal
Although like all members of the family Malvaceae, M. sylvestris is not long-lived and it readily reproduces, flowers and seeds freely. The fact that it is occasionally observed growing in wall crevices high above the ground proves that Common Mallow must have definite powers of dispersal to reach such sites (Ridley 1930, p. 27). However, unless strong winds or birds transport the fruit nutlets, it is difficult to imagine a reliable seed dispersal mechanism. Praeger (1913) experimentally showed that seeds retain their viability in water for up to 36 hours, so they may also disperse along streams and around sheltered lake shorelines by flotation (Ridley 1930, p. 201).
Variation
Although previously regarded as a single species (Stace 2010), or with a single variety with hairy mericarps (var. lasiocarpa Druce) (Clapham et al. 1987), three varieties are now recognised by Sell & Murrell (2018). Var. sylvestris is either perennial or biennial and has erect stems and glabrous mericarps; var. socialis Griseb. is perennial and has spreading or prostrate stems, a densely hairy inflorescence and mericarps with simple eglandular hairs. Finally, var. incanescens Griseb. is an erect biennial with small leaves covered with stellate hairs beneath; it also has mericarps with simple eglandular hairs.
Fermanagh occurrence
The Revised Typescript Flora commented that Common Mallow was, "still cultivated in cottage gardens, and probably always is a recent escape elsewhere". In Fermanagh, M. sylvestris has been recorded in a total of 18 tetrads (3.4%) and is occasional about Upper Lough Erne and rare and thinly spread elsewhere. Nine of the 17 post-1975 records were made on lakeshores (or possibly on nearby access roads and fields), during the 1986-7 DOE survey of Upper Lough Erne. Two of the most interesting stations are the Green Lough limestone turloughs near Fardrum, where R.S. Weyl recorded it on 20 June 1985, and Trien Mountain, a limestone hill above the Florencecourt estate, where A. Waterman discovered it on 11 October 1989. Other Fermanagh sites are on roadsides and waste ground, generally near habitation.
Irish occurrence
M. sylvestris has long been considered a probable introduction in Ireland (Scannell & Synnott 1987; Parnell & Curtis 2012), but in more recent years it has been recognised as a definite garden introduction (Preston et al. 2002; Stace 2010). In parts of the N & W of Ireland, Common Mallow shows a very definite coastal affinity, colonising and persisting in sandy and gravelly situations. On the shore of Co Down M. sylvestris is a regular member of the upper littoral plant community (Hackney et al. 1992; NI Flora Website 2006).
British occurrence
While M. sylvestris is common and widespread in most of lowland England and Wales, the New Atlas hectad map indicates it has a definite southern and eastern predominance. Previously the species was regarded as native in Britain (eg Stace 1997), but it is now recognised as an ancient garden introduction (an archaeophyte) (Preston et al. 2002; Stace 2010). In Scotland, the species is much more thinly scattered, becoming confined to coastal areas, mainly in the east of the country as one travels northwards. It is absent from the Outer Hebrides, Orkney and Shetland (Preston et al. 2002).
European and world occurrence
The original distribution of M. sylvestris was probably restricted to mainland Europe, N Africa and W Asia. However, it has long been cultivated as a garden subject and has been introduced to many countries around the world, including N & S America, S Africa, E Asia, S Australia and New Zealand (Hultén & Fries 1986, Map 1302).
Threats
None.