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Atriplex patula L., Common Orache

Account Summary

Native, frequent and locally abundant. Eurosiberian wide-temperate, widely introduced in both hemispheres.

1900; Praeger, R.Ll.; Co Fermanagh.

June to December.

Growth form and preferred habitats

This very variable, phenotypically plastic, ruderal summer annual is a fairly common pioneer colonist on a variety of lowland, open, artificial habitats (ie created or heavily influenced by man). The large triangular or rhombic paired vertical bracteoles clasping the fruit on mature plants of A. patula are very obvious and enable its ready distinction from Chenopodium album (Fat hen), a related species with which it very often occurs.

Like all members of this family, A. patula prefers loose, nutrient-rich, loamy substrates, which is why it is so prevalent in gardens and in arable fields. Examples of the latter habitat are now few and far between in Co Fermanagh. Otherwise, Common Orache crops up in fertile or nutrient-enriched situations, including around rubbish tips, manure heaps, margins of farm yards and, in this area, occasionally in disturbed trampled ground or exposed mud around eutrophic lakes and ponds. Other disturbed habitats include quarries, sand-pits, roadsides and car parks. Like other Atriplex species, it is frequent and sometimes locally abundant in maritime habitats (Grime et al. 2005).

Given a moderate degree of surface disturbance, A. patula occurs on a wide range of substrate textures, from sand and gravel to loam and clay, but it avoids strongly acid peatland. Around Sheffield, Grime et al. (1988) found it ± restricted to soils of pH above 5.0.

Flowering reproduction

A. patula is most conspicuous in late summer and early autumn when it reaches the flowering and fruiting stages (June to November). Unlike Chenopodium species, which have perfect flowers each containing both male and female parts, Atriplex flowers are unisexual. The monoecious plants have dense male and female flower clusters arranged on the same spike. The male Atriplex flowers have a small perianth of five tepals or segments, unlike the female ones which completely lack a perianth, the naked ovary being simply enclosed within a pair of small, leaf-like bracteoles. In A. patula, the margins of these bracteoles are united almost to midway along their length, a feature which distinguishes this species from the only other, locally very much rarer Atriplex in Fermanagh, A. prostrata (Spear-leaved Orache). The latter has bracteoles united only at the base.

Being facultatively autogamous, the tiny green flowers are pollinated either commonly by wind, or rarely by insect, or if these both fail it can self-pollinate, thus ensuring a good seed-set. Again like Chenopodium species, A. patula has the potential to seed quite prolifically, the average plant producing around 6,000 seeds. The seed is shed still enclosed by the two fleshy bracteoles.

Other biological similarities exist between this species and C. album in that both these weedy ruderals produce two types of seed: larger brown non- or less-dormant ones, and small, black, shiny seeds that are long-persistent in the soil seed bank. About 90% of A. patula seeds were of the latter type, and even after three experimental cultivations of the soil each year for five years, quite a high proportion of the seed remained dormant and viable (ie between 8.6% and 19.2% of three separate sowings) (Roberts & Neilson 1980). It has also been shown that A. patula seed are capable of surviving dormant in undisturbed soil for three decades or more (Brenchley 1918).

Native status

The Irish Census Catalogue regards the status of A. patula as "possibly introduced" (Scannell & Synnott 1987). There appears to be sufficient British fossil records from two earlier interglacials, plus evidence of persistence during the last glacial period, to suggest that a similar pattern of behaviour and survival would be even more likely in Ireland. This would make the species, despite its current weedy nature, more probably indigenous than an ancient introduction of Bronze Age or later date (Godwin 1975).

Fermanagh occurrence

It is widespread in lowland Fermanagh having been recorded in 139 tetrads, representing 26.3% of those in the VC. A. patula is about twice as frequent and widespread in the county as the ecologically and biologically rather similar Chenopodium album (Fat-hen), with which it can readily be confused.

British and Irish occurrence

Common Orache is common and widespread throughout most of Britain & Ireland, becoming less so in N Scotland and W Ireland, a distribution pattern often assumed to reflect avoidance of wetter, cooler, more acidic soil conditions (Preston et al. 2002).

European and world occurrence

A. patula is widespread in Europe except the far north. It is also present in N Africa and W Asia and is naturalised in N America. It has also been introduced in parts of the southern hemisphere, including S America, S Australia and New Zealand (Hülten & Fries 1986, Map 694).

Uses

Common Orache is described by Grigson (1987) as "a poor man's pot-herb", like Chenopodium bonus-henricus (Good-King-Henry) or C. album, and close enough related to both plants to share the common names of 'Fat Hen' and 'Lamb's Quarters'. These three plants were collected, boiled, pounded and mixed with butter and served in the same manner as Spinach is to this day.

Names

The genus name 'Atriplex' is the classical Latin name of a plant in Pliny, now applied to this group of species. One suggestion for the derivation (however fanciful, or not), is from the Greek 'a' meaning 'no' and 'traphein' meaning 'nourishment', several species of the genus known to be capable of growing in arid, desert soils (Johnson & Smith 1946; Gilbert-Carter 1964). The Latin species name 'patula' means 'spreading', which could apply equally to any of the species in the genus. The English common name 'Orach' or 'Orache' again refers to any member of the genus, all of which can be, and were in the past, boiled and used as leafy vegetables in the manner of spinach. The name 'orache' or 'arach' comes through French 'arroche' directly from the Latin genus name 'atriplex' (or 'atriplice') (Prior 1879), and this in turn is from the Greek 'atraphaxis' in Dioscorides (the father of medicine) (Grigson 1987). It has also been suggested that 'orache' is a corruption of 'aurum' meaning 'gold', because the seeds, mixed with wine, were supposed to cure yellow jaundice (Watts 2000).

Other English common names include 'Lamb's Quarter' or 'Lamb's Quarters', a corruption of 'Lammas quarter', from its supposed blossoming about the first of August, old style, the day of a church festival instituted as a thanksgiving for the first fruits of the harvest, when an oblation or offering was made of loaves baked with the new season's corn (Prior 1879). Yet another name, 'Hard Iron', is applied to three quite different unrelated species Centaurea nigra (Common Knapweed), Ranunculus arvensis (Corn Buttercup) and Atriplex patula). In A. patula, the attribution is said to refer to the root, which is described as being as hard as iron, while in the other two species, the name refers to the flower buds or flowerheads (Watts 2000). Personally speaking, I find this supposed root property, of what is after all a summer annual, to be highly fanciful. However, I have no alternative explanation to offer as to the origin of this peculiar common name.

Threats

None.