SECTION 4.5 CHARRED
PLANT MACROFOSSILS
by Vanessa Straker, Martin Jones and Ann Perry
INTRODUCTION AND METHODOLOGY
THE MIDDLE IRON AGE, PHASE 1 (3rd - 1st
Century BC)
THE LATE IRON AGE AND ROMAN PERIODS (Phases
2-4)
Phase 2 c AD 25-125 Late Iron Age – early Roman
Phase 3 c AD 125 - early 4th century AD (Roman settlement
complex)
Phase 3D/4A late third – early/mid 4th century
AD
Phase 4 4th century AD (The late Roman Villa)
SUMMARY AND DISCUSSION
The crops
Weed communities
Sowing and harvesting
Differences in agricultural and domestic activity
over time
Multiple samples from linear features – macrofossil
concentrations
Crop processing and harvesting: recent and new models
for interpretation
ACKNOWLEDGEMENTS
BIBLIOGRAPHY
Introduction and methodology
The sites comprise a variety of late prehistoric and Romano-British
settlements, fields and trackways and straddle the first gravel terrace
near the confluence of the Coln and Thames c. 3km west of Lechlade and
c. 18km east of Cirencester. The gravel terrace was dissected by watercourses
and marshes with tongues of gravel providing better drained sites suitable
for settlement. The low-lying nature of the site provided good conditions
for the preservation of both waterlogged and charred plant macrofossils
as well as pollen, insects and snails. Robinson (this vol.) reports on
all of these apart from the charred remains, which are the subject of
this report.
The Middle Iron Age site was excavated in 1979-81 and the
charred plant macrofossils result from an extensive sieving programme
designed by Martin Jones and Anne Perry to extract material from the non-waterlogged
deposits. Perry and Jones carried out the identifications (Perry for her
3rd year placement as part of a course at Bradford University).
The samples were checked and a report written in 1984 (Jones, Perry and
Straker, 1984).
The late Iron Age and Roman phases (first to 4th
century AD) were excavated in 1980-4 and a similar sampling programme
to that for the Middle Iron Age settlement was implemented for the later
phases. The charred plant macrofossils were identified and reported on
by V.Straker (Straker, 1988).
Since the 1980’s, further post excavation analysis has resulted
in changes to the phasing and as a result it has proved necessary to re-make
all the species identification tables and this report attempts to interpret
the results of that work. No doubt if time allowed, further interpretation
would be possible, but the data in its current form (Tables 1-20) allows
other specialists to draw their own conclusions should they wish to. The
Claydon Pike data is published in full for the first time in this report.
The very thorough sample processing records made in the
early 1980’s have enabled macrofossil concentrations to be calculated
for all the samples. Methodology for post excavation analysis has developed
since the 1980s and if the project was carried out today the floats would
first be subjected to a post excavation assessment. As Tables 1-20 show,
plant macrofossil concentrations are generally low. If the project took
place today, many samples would not go on to receive full analysis. A
further point is that by the standards of today the samples are small,
many being c. 10 litres in volume. A sampling programme would collect
samples in the order of 40 litres in volume, where this is possible, to
attempt to recover assemblages of a useful size (English Heritage, 2002).
Linear features (ditches and house gullies) had 2-3 random
samples taken along a 15-metre length, and selective samples were taken
from pits, post-holes and other non-linear features. In general the samples
represented about 20% of each feature with slightly less for the larger
than average features. The importance of multiple samples from linear
features is commented on in the discussion section at the end of this
report.
The sample summary information is presented in Table
18 and Figure
4.5.1: Phases 1-4: sample summary. Seventy four samples (832 litres
soil) were analysed from Phase 1 and 40 (271 litres), 50 (465 litres)
13 (121 litres) and 19 (180 litres) from phases 2, 3, 3D/4A and 4 respectively.
Originally, about 300 samples had been collected from the Late Iron Age
and Roman phases. Some, with the benefit of hindsight, were regarded as
dubious stratigraphically and excluded from further consideration, and
a few others contained no plant remains. The remaining selection was made
so that a wide a range of context types within each phase was examined,
and where there were large numbers of samples, as in the case of gullies
and ditches, random numbers were used to select those for analysis.
Floats were recovered on a 0.5mm mesh and residues on a
2mm mesh. Flotation was effective and the residues were sorted principally
to recover small bones (M Robinson pers. comm.).
Cereal identifications are only made to species when the
presence of chaff allows. Some grains with a distinctive morphology have
been tentatively (using cf.) assigned to a particular taxon, but it is
recognised that grain morphology is variable and not reliable for close
determinations. The summary information presented in the Figures classifies
all wheat grains as Triticum species, apart from Figure
4.5.3: Percentage presence of crops (excluding chaff) where some
grains are assigned to T. cf. aestivum type.
Nomenclature and habitat information for weed species follows
Clapham et al. 1987 as this was used in the original report and
is the same reference used by Robinson (this vol.). Nomenclature for crops
follows Zohary and Hopf 1994, Tables 3 and 5and the rationale
for wheat identification is based on Hillman et al., 1995.
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The Middle Iron Age, Phase 1 (3rd
– 1st century BC) (Table 1 a-d, Figures 1-8)
The Warrens Field settlement was located on 3 gravels islands
and consisted of round houses, typically sited inside a circular drainage
gully with an entrance to the south east. The plant macrofossils were
recovered from gullies (mainly) and some ditches and clay-lined pits excavated
in trenches 6 (Island 1), 8 and 12 (Island 2) and 14 (Island 3).
The assemblages are very small and are dominated by weed
seeds and chaff rather than cereal grain. Plant macrofossil concentrations
(number of items per litre of soil) are shown in Tables 1 and 17,
19 and Figure
4.5.2: Plant macrofossil concentrations . They are low, with a
mean of 1.5 for gullies and 1.3 for ditches. As in all phases, pits have
a slightly higher density with a mean of 3.8 for the Middle Iron Age,
which is still very low. These sorts of figures are difficult to interpret
but relate to the nature of the activities taking place in the vicinity.
They can also show the patchy nature of deposition in linear features
as demonstrated by gully context 21a with over 6 items per litre compared
with 0.6 for context 21c.
The assemblages tend to be dominated by crop processing
waste (chaff and weed seeds). The information from grain and chaff shows
that of the crops, wheat was more commonly present in contexts than barley
(see Table 20 for percentage presence
of different components). The wheat chaff allows identification of hulled
wheats suggesting that spelt wheat predominated, though a single rachis
internode of free threshing wheat, probably hexaploid Triticum aestivum
sl. (bread wheat) was also identified. This is the only example of
free threshing wheat rachis node from a Middle Iron Age context in the
south of England (Campbell and Straker, 2003). It is likely that emmer
wheat and bread wheat were minor components of the wheat crop. The barley
was not well preserved, rarely allowing distinction of the (more likely)
hulled from naked form, but the absence of twisted grains suggests that
the 2-row form with 2 as opposed to 3 grains maturing at each rachis node
predominated.
Most of the charred weed seeds are associated with arable
land or grassland, though some will live in a more varied range of habitats.
Numbers of weed seeds are generally low though a fairly wide range of
taxa was identified. Members of the Caryophyllaceae (e.g. Stellaria
media agg., chickweed) were among the most numerous and are associated
with arable or disturbed conditions. Spike rush (Eleocharis spp.),
was also common; this plant is associated with soils experiencing at least
spring waterlogging (Walters, 1949) and pond margins. Scentless mayweed
(Tripleurospermum maritimum) is an arable weed, but prefers lighter,
drier cultivated soils and was found more commonly at Ashville (Jones,
1978). Sheep's sorrel (Rumex acetosella agg.) has a competitive
advantage over many other species in acid soil conditions but also grows
on the largely calcareous gravels of the Thames Valley today (M.Robinson,
pers. comm.).
Cleavers (Galium aparine) was quite common at Claydon
Pike, as it also was at Ashville, and is regarded as a weed of winter-sown
cereals. Taxa associated with open grassy habitats are numerous and include
Clover (Trifolium sp.), Vetches (Vicia/Lathyrus), Eyebright
or Bartsia (Euphrasia/Odontites) as well as several different grass
taxa.
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The Late Iron Age and Roman periods
(Phases 2-4) (Tables 2 to 17)
A range of contexts (gullies, ditches, pits, wells, layers,
ovens and hearths) was examined from the three platforms, rectangular
temenos and circular shrine excavated between 1980 and 1984. The dating
available for the late Iron Age and Roman periods allows the main phases
to be subdivided, as shown in the Tables. Brief summaries of the results
for each phase are presented below. A general summary of the crops and
weeds is presented in the final discussion section.
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Phase 2 c AD 25-125 Late Iron Age
– early Roman (Tables 2, 3, 4, 5 and 6)
40 samples were analysed from 10 circular gullies, 17 ditches,
3 pits and 1 layer which comprised what was thought to be a nucleated
settlement, though no directly structural remains were identified from
it. This may be reflected in the very small assemblages and low concentration
of macrofossils (Figure
4.5.2: Plant macrofossil concentrations ), with only the assemblage
from gully 1645a of more than 50 items. Cultivated plants include emmer
(Triticum dicoccum), spelt (Triticum spelta) and breadwheat
(Triticum aestivum sl) and the wild species are all from
open and disturbed habitats. They include Field madder (Sherardia arvensis),
sheep's sorrel (Rumex acetosella agg.) and Brome (Bromus,
probably B. mollis or secalinus) clover (Trifolium sp.)
and self heal (Prunella vulgaris). However, the range of wild plants
is smaller than in both the Middle Iron Age and later in the Roman period.
The impression, with the exception of gully 1645 where grain predominates,
is of occasional discarding of waste from the later stages of crop processing
where small chaff such as glume bases and weed seeds predominate.
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Phase 3 c AD 125 - early 4th
century AD (Roman settlement complex) Tables 7, 8, 9,
10, 11, 12 and 13)
In this phase the settlement was reorganised with large
rectilinear ditched enclosures, 2 aisled buildings, fence lines and a
cobbled trackway. Fifty samples were analysed from 3 gullies, 15 ditches,
5 pits, 4 wells, 2 layers and 4 ovens, distributed over the sub phases
as shown in Table 18.
The range of farming and domestic activities taking place
at the settlement throughout the early second to early 4th
centuries was probably varied and is reflected by the heterogenous distribution
of grain, chaff and weeds in the samples and the much greater concentration
of plant macrofossils than in earlier phases (Table 19; Figures
4.5.2: Plant macrofossil concentrations and
4.5.7: Percentage presence of grassland plants). The 50 samples
from phase 3 compare with 40 from phase 2 and 19 from phase 4, with more
samples in phase 3 from a range of features other than ditches. Some individual
features (e.g. oven 2103, see below) are very rich, but the mean macrofossil
concentration is also greater. The figure for phase 3 pits, for example,
at 117.5 items /litre is noticeably greater than for phases 2 and 4 (1.7
and 10.2 respectively).
The range of crops is similar to earlier phases but the
very rare occurrences of beans (Vicia faba var minor) and
flax (Linum usitatissumum) are found in phases 3A and 3D respectively.
Neither of these crops is as likely to become accidentally charred as
the hulled wheats, which benefit from heat to render the chaff brittle
and facilitate dehusking.
Oven 2103 (not allocated to a subphase within 3) is very
rich in chaff, notably emmer and spelt glume bases and spikelet forks
which comprise over 80% of the large assemblage. These are the remnants
of the oven fuel which was probably also disposed of in ditches, pits
etc. Many of the other features from phase 3 are also chaff-rich and some
could have originated from oven cleanings, rather than the direct burning
of crop cleanings. However, as well as chaff, the oven assemblage also
contains small weed seeds including over 100 seeds of stinking chamomile
(Anthemis cotula) and occasional ribwort plantain (Plantago
lanceolata) and sedges (Carex spp.). This is most likely to
represent processing waste from a late stage in cleaning to free the grain
from the spikelets and remove weed seeds. The damp ground plants could
be from damp field margins or burnt animal fodder, but also from the heart
of the arable fields, which often suffered from poor drainage in the Iron
Age and Roman periods (Jones 1988).
Another large assemblage from pit 1398 is composed mainly
of wheat grain, probably spelt, as suggested by the chaff, with some indeterminate
wheat and barley grain and chaff. Among the accompanying list of taxa
is a wide range of wild plants, and a relatively high number of clover
seeds, perhaps indicative of animal fodder or hay as a source.
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Phase 3D/4A late third – early/mid
4th century AD (Table 14)
Fifteen samples from 1 gully, 4 ditches and 6 pits fall
within this phase. Macrofossil concentrations vary as shown in Figure
4.5.2: Plant macrofossil concentrations , ranging from 0.6 for
ditch 1201k to 50.3 items per litre for pit 2385. Composition is also
variable with over 80% chaff in ditches 667f and pit 1250, 55% in ditch
section 1201j and over 70 % weeds in pit 1219 which suggests that a range
of different crop processing activities was probably taking place and
/ or that crop processing waste is mixed with burnt plant debris from
other sources, such as animal fodder and roofing or flooring material.
Figure
4.5.4: Percentage presence of chaff shows a greater percentage
presence of chaff than for other phases, but unusually, these samples
are from ditches and pits rather than hearths or ovens where chaff is
often found having been used as tinder.
Pit fill context 2385 was rich in plant macrofossils. Wheat
and barley grain was mixed with hulled wheat (mainly spelt where identification
was possible) glume bases and spikelet forks, but there were also small
numbers of a range of weeds or arable land and grassland such as corn
cockle, knotgrass, black bindweed, stinking chamomile and buttercups,
clover and tormentil. There were also some sedges and spike-rushes characteristic
of damp ground. This is a good example of a rubbish pit where waste from
processing crops to release grain for consumption was dumped probably
after being burnt on a domestic hearth.
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Phase 4 4th century
AD (The late Roman Villa) (Tables 15, 16 and 17)
The villa estate consisted of a masonry-footed villa and
associated buildings, a small cemetery and a circular shrine. By the later
4th century (phase 4C) the villa was enclosed by the first
of two ditched enclosures. Seventeen samples were analysed from 5 ditches,
2 pits, 1 layer, 1 oven and 1 hearth. The breakdown by sub phase is shown
in Table 18.
Spelt and emmer wheats are still consumed, as was barley.
There are internode fragments of neither barley nor free-threshing wheat.
Bread type wheat may still have been a minor component of the cereal fields
but there is certainly no evidence from Claydon Pike to show that it was
increasing in importance.
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Summary and discussion
The crops
Wheat and barley are identified from all phases on the basis
of grains and chaff with the exception of barley rachis internodes, which
were not recorded in phase 4. The figures for percentage presence (based
on the percentage of samples in each phase in which the taxon occurs)
(shown in Table 20 and Figures
4.5.3: Percentage presence of crops (excluding chaff) and
4.5.4: Percentage presence of chaff), demonstrate that as for
the Middle Iron Age, wheat macrofossils occur more commonly than barley.
Triticum sp. Wheat
On the basis of percentage presence in samples as outlined above, spelt
wheat (Triticum spelta) is the species most commonly found in all
the phases. This hulled wheat is largely identified by its distinctive
chaff, principally glume bases. Some wheat grains have been tentatively
assigned to species, but grain morphology is notoriously variable between
as well as within species. Emmer chaff (T. dicoccum) is present
as a minor component in phases 2C, 3 and 3/4. Although present in the
Thames Valley, the archaeological evidence shows that emmer has completely
disappeared from the Hampshire chalklands by the beginning of the Iron
Age, which demonstrates the local distinctiveness of farming practices.
In other parts of southern England however, emmer was probably a more
important component of Roman farming (Campbell and Straker, 2003).
Some rounded caryopses typical of a free threshing bread
wheat type were noted occasionally in all phases but the presence of free
threshing wheat is only confirmed by the presence of a small number of
tough rachis internodes (probably hexaploid, bread wheat type) in phases
2C and 3.
The significant presence of spelt, with emmer and smaller
amounts of breadwheat is typical of Roman assemblages. There may be an
exception at Barton Court Farm (Jones 1984) but some of the material may
have been wrongly assigned (Campbell and Straker 2003). However, free
threshing cereals are likely to be under represented in the charred macrofossil
record in relation to hulled wheats as they do not require exposure to
heat to facilitate dehusking and can be removed at an early stage of crop
processing (Hillman, 1984).
Hordeum sp. Barley
Most of the barley grains (as with the wheat) are poorly preserved and
cannot be identified very closely. Some can be identified as hulled barley.
Both twisted and straight grains were noted, but the twisted grains were
uncommon and only present in phases 2 and 3. In six-row barley, the grains
in the lateral florets have a twisted ventral furrow whereas the grains
in the middle floret have a straight furrow. The ratio of twisted to straight
grains for six-row barley is 1.5:1 or less, as it is quite usual for some
lateral florets to fail to develop. In two-row barley, twisted (asymmetrical)
grains do not generally occur. However, as so many of the grains are indeterminate,
it is only possible to say that hulled six-row barley was consumed and
hulled two-row barley may also have been. No naked barley was observed.
Avena sp. Oats
Oats are very scarce in all phases and it is not possible to tell from
the grain alone whether a cultivated or wild form is present. The only
floret base is from Phase 3 and identifiable to a fatua or ludoviciana
wild form. It is likely that the oats are simply a minor weed component
which, like the large-seeded Bromus (brome), are difficult to separate
from the grain during winnowing and sieving in post-harvest crop processing.
This means they often become accidentally charred with the prime product.
It has been pointed out that the large seeded grasses may well have been
intentionally used as a famine food, but Jones (1988, 90) notes that sometime
after the Iron Age, wild grasses become much less numerous in charred
macrofossil assemblages.
Other crops
Flax is known to have been an important crop in the Thames
valley and it grows well rotated with other crops on wet ground. Its seeds
have been found at Barton Court Farm and Farmoor (Jones 1984, and Lambrick
and Robinson 1979). Only one carbonised seed was found at Claydon Pike,
from an oven (Phase 3B 2113/3) but it is more plentiful in the waterlogged
assemblage (Robinson, this volume). It is a useful crop for as well as
providing bast fibres for textiles, its seeds are oil rich and can be
used for the oil or as cattle feed.
Legumes are usually under represented in charred macrofossil
assemblages as they, like free threshing cereals, do not require exposure
to heat after harvest. Legumes identified as vetch or pea (Vicia/Pisum)
were found in phases 2,3 and 4 but unfortunately the hila were not well
preserved enough for precise identification to be made. Legumes identified
as vetch or pea were also very scarce but noted in phases 2 and 3. The
only example of a Celtic bean (Vicia faba var. minor) was
found in ditch sample 547E from phase 3A. It is very likely that pulses
were a much more important component of the diet than it would appear
from the archaeological record alone and may have been an important source
of plant protein. Beans, peas and other legumes are nitrogen fixing and
if grown as part of a rotation, help to maintain soil fertility. Roman
peas were identified from the Warwickshire gravel site at Tiddington (Moffett
1986).
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Weed communities
The ecological analysis of weeds can either proceed through
a single species (indicator) or plant community (phytosociological) approach.
The latter relies largely upon observations of modern plant communities.
Some reservation in the use of this approach is advisable for two reasons.
First, it may be that the ecological preferences and tolerances of weeds
have changed somewhat over the last few thousand years. Second, and more
importantly, the actual soil environment of arable agriculture has radically
changed with each change in cultivation technology, and such innovations
as the mouldboard plough transformed the selection pressure on arable
weeds. Indeed that was the central purpose of such innovations (Jones
1988).
In relation to the first of these points, the oceanic climate
of Britain reduces the clarity of distinctions observable on the continent,
between, for instance, weed communities of spring and winter-sown cereals.
This said, many of the arable weeds from Claydon Pike (shown by phase
in Figure
4.5.5: Percentage presence of plants of disturbed ground and arable),
do correspond with the taxa included in the Class Stellarietea, described
by Silverside (1977) to which most present-day arable communities are
referable. Some species, such as Lapsana communis, Anthemis cotula,
Atriplex patula and Odontites verna are more particularly characteristic
of cereals (the order Centauretalia cyani). In recent years, a
series of volumes describing British Vegetation Communities has been published.
Volume 5 (Rodwell, 2000) describes the vegetation communities of open
habitats including arable land and waste ground. It is clear from this
that aspects of the Claydon Pike weed flora are reminiscent of several
of the communities described (e.g. OV3, 0V7, 0V9, OV10, OV13), but close
comparisons are not possible. This may be largely due to the increasing
use of herbicides on open ground vegetation in the 20th century,
especially in arable fields, which is a major contrast with former farming
methods.
In relation to the second of these points, certain taxa
appearing first in phase 3 have been associated by one of us with the
transition from shallow ard cultivation to deep ploughing (Jones 1988).
Stinking chamomile (Anthemis cotula), a cornfield weed typical
of heavy soils, makes its first appearance in Phase 3 and another introduction,
corn cockle (Agrostemma githago) is first seen in phase 3D/4A.
More widely in Britain, these two species together with Centaurea cyanus/nigra,
become visible in the late Roman period at a time when metal items associated
with heavier ploughs appear in the archaeological record (Jones 1988).
It is interesting to note that three taxa conversely associated with shallow
ard cultivation are at their most frequent, and their most abundant, in
the earliest phase of the site, phase 1.
The range of arable weeds is most diverse in phase 3, as
shown in Figure
4.5.5: Percentage presence of plants of disturbed ground and arable,
but there are some notable differences in phase 4 with the presence of
corn gromwell (Lithospermum arvense) and particular abundance of
field madder (Sherardia arvensis) and stinking chamomile.
The last two plants prefer slightly different growing conditions, with
field madder typical of dry soils such as sands and gravels whereas stinking
chamomile is most common on heavy soils. This suggests that the crops
processed at the late Roman villa were grown on a wider range of soil
types than those exploited by the earlier communities.
A single seed of ground elder (Aegopodium podograria)
was found in pit 1398 in phase 3. Although now regarded as a pernicious
garden weed, this species is long thought to have been a Roman introduction
and can be used as a pot herb (Clapham et al. 1989, 283; Godwin,
1975, 225). The Claydon Pike example appears to be the sole archaeological
record for the period.
Clovers (Trifolium spp.), black medick (Medicago
cf. lupulina), buttercups (Ranunculus acris/repens or bulbosus)
and yellow rattle Rhinanthus sp.) increase from phase 3 onwards
(Figure
4.5.7: Percentage presence of grassland plants). All of these
taxa (and others) are recorded by Mark Robinson in the waterlogged assemblages.
From his waterlogged data, he infers that grassland was managed and included
the production of sedge hay. The plants of damp soils such as the sedges
may have formed part of a burnt grassland assemblage, however the wide
range of taxa that survives in the waterlogged assemblages is not reflected
by the charred plant remains although the percentage presence analysis
does show a wider range of weed species in Phase 3 than in earlier and
later phases. The integration of the different strands of evidence in
the waterlogged assemblages led Robinson (this vol) to the conclusion
that large quantities of arable products must have been brought to the
site, as they did not appear to have been grown locally. Certainly the
evidence for the use of arable crops is much better in phase 3 than in
the preceding periods or the 4th century villa complex. As
large areas were excavated, the increase in evidence for phase 3 should
be a reasonable reflection of the activities taking place rather than
being biased through sampling of features closer to the main areas of
activity in one phase compared with another.
Plants of damp ground such as sedges and spike-rushes in
particular are rather more commonly found in phases 3D/4A and 4 than elsewhere
(Figure
4.5.6: Percentage presence of damp ground plants). As suggested
above, these may relate to a variety of sources, and as Robinson (this
volume) has shown, damp grassland was a major feature of the local environment.
However, the association of seeds of plants today associated with damp
and wet ground, with crop and arable weed communities has been noted for
a number of Iron Age and Roman sites in the Thames Valley (e.g. Ashville,
Jones 1978, and Barton Court Farm, Jones 1984) as well as being noted
among cereals on the continent (Groenman van Waateringe and Pals, 1983).
It has been suggested (e.g. Jones 1988) that the frequent finding of the
seeds of these types of plants charred with arable weeds seeds provides
evidence that fields were being cultivated in areas that became increasingly
subjected to flooding. This may be the case for the fields of the villa
estate, alongside the possibility of other taphonomic routes from neighbouring
grassland.
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As far as time of sowing can be ascertained, the presence
of species such as Galium aparine (cleavers), an autumn germinating
plant, suggests that at least some autumn sowing of crops was taking place
from the Middle Iron Age onwards. Black bindweed (Fallopia convolvulus),
chickweed and stitchwort (Cerastium sp. and Stellaria media
agg.) are typical indicators of spring sowing. Many of the weeds are
low-growing species suggesting that reaping was low on the straw. Examples
include eyebright or red bartsia (Euphrasia sp. / Odontites
verna), and members of the Caryophyllaceae family such as chickweed
and stitchwort. The Caryophyllaceae are particularly frequent in the Middle
Iron Age samples, as shown in Figure
4.5.5: Percentage presence of plants of disturbed ground and arable.
In contrast, black bindweed seeds would have been harvested with the ears
or ears and straw.
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Differences in agricultural and domestic
activity over time
Pie diagrams divided to show the proportions of grain, chaff
and weeds were constructed for all assemblages with more than 50 items
and were matched by eye to their locations on the respective site plans
to see any parts of the site may have specialised in particular activities
at any time. The diagrams are deposited with the site archive. No particular
spatial patterns could be seen in either concentration or composition
with the exception of oven 2103 in phase 3, which has been discussed.
Many samples probably result from the mixing of waste from different activities
or storage practices leading to charring and as Stevens (2003) suggests,
this could have taken place over months or years.
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Multiple samples from linear features – macrofossil
concentrations
The figures for macrofossil concentration given in Tables
1 to 17 for the multiple samples from different l5 metre stretches within
the linear features, demonstrate well the patchy nature of deposition
in ditches and gullies. This was more noticeable for the Roman than earlier
periods. These differences may have been more noticeable had larger samples
been taken; the results obtained here cannot be used to infer differences
in farming or domestic practices in different areas. However, the data
serves as a reminder that sampling strategies for sites with large numbers
of linear features should include multiple samples, each kept and processed
separately, in order to ensure that assemblages are as representative
of what was originally present as possible. This is summarised well by
Orton (2000, chapter 6) who noted the lack of homogeneity within features
and examined the approaches to sampling by several specialists. He comments
that in order for calculations made should be valid, several samples from
the same feature are preferable to one large one from a single location.
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Crop processing and harvesting:
recent and new models for interpretation
Since the excavations at Claydon Pike in the late 1970’s
and early 1980’s, there has been much discussion on the use of charred
plant macrofossil assemblages to try to identify the sorts of post-harvest
crop processing activities that have taken place in the past and establish
the existence of specialist farming settlements of an arable or pastoral
nature.
The first model to be put forward was by Hillman (1981,
1984), and a further model also based on ethnographic evidence but using
the characteristics of weed seeds, was published by G.Jones (1984). In
1985, M. Jones published a model for the interaction of Iron Age communities
in this part of the Thames valley based on the composition of archaeobotanical
assemblages. He suggested that sites dominated by fine chaff and weed
seeds (presumed to be derived from final cleaning of partially cleaned
spikelets), rather than large quantities of grain, could represent ‘consumer’
economies of predominantly pastoral groups. He suggested that the Middle
Iron Age assemblage from Claydon Pike was an example of this, as was Smith’s
Field. Both sites were located at the junction of the river floodplain
and first gravel terraces. Subsequently (Jones 1993), the settlement at
Mingies Ditch was also interpreted as a ‘consumer’ site. Settlements such
as Ashville and Mount Farm, located on the second (higher) terrace more
suitable for arable cultivation, were grain rich and could be viewed as
‘producer’ settlements.
Van der Veen (1991, 1992) pointed out that the approaches
of Hillman and M. Jones were in conflict and went some way to try to resolve
the differences. She concluded that the ‘producer and consumer’ model
was rather too simplistic and suggested at least four types of settlement.
These were those engaging in subsistence production, production for a
surplus, small consumer sites and large urban complexes. Van der Veen
suggested that there would be a continuum between these types of site.
Van der Veen’s surplus production, typified by large, grain rich assemblages,
would look similar to assemblages thought to represent a producer settlement
using M.Jones’s interpretation (Van der Veen 1991, Fig 27.2 and 355, 357).
Assemblages from small consumer sites however, could look very like production
on a small scale.
A recent paper by Stevens (2003) summarises the discussion
in some detail and the reader is referred to it for further information.
Stevens (2003) re-worked some of M. Jones original data from Ashville,
Mount Farm, Mingies Ditch and the Middle Iron Age samples from Claydon
Pike. He also used data from Gravelly Guy (Moffett 1989) and Yarnton.
He used a different approach to interpreting charred assemblages and also
suggested that social organisation including the availability of post
harvest and pre storage labour, could have played a part in different
storage practices, which in turn affect the composition of the charred
assemblages. Stevens used two different methods to analyse the data from
the sites. One of these (the percentage of large weed seeds from all classified
seeds plotted against the percentage of weed seeds to grain, Stevens,
2003, Fig 6) produced clear variations between the sites included in his
study. The interpretation he proposed was that waste from a number of
crop processing stages, including processing of spikelets, was present
at Claydon Pike, with a similar situation for Abingdon, Yarnton, Gravelly
Guy and Mingies Ditch. Stevens comments that different storage practices
could also produce the observed pattern. In contrast, the assemblages
from Ashville, Mount Farm and Danebury, were dominated by grain as opposed
to weeds and of the weeds, large seeds in preference to small and intermediate-sized
ones. This fitted the expected pattern from his model for waste produced
from the processing of semi-cleaned spikelets.
The method of analysis described above has been applied
to the data from each of the different phases at Claydon Pike, Stevens
(2003) having only applied it to the Middle Iron Age data. The number
of large seeds is expressed as a percentage of all the seeds classified
as large to small, plotted against the number of all weed seeds expressed
as a percentage of weed seeds plus grain. The results are presented in
Figure
4.5.8: Weeds as % of weeds and grain plotted against large weed seeds
as % all classified seeds . Stevens’s methodology was followed
in terms of using samples with the minimum required diagnostic components
(15) per assemblage. Time has not permitted development of the technique
to include other large or small weed taxa which would be diagnostic for
Claydon Pike. The information presented in Figure
4.5.8 is therefore limited in this respect and for most phases
there are very few ‘qualifying’ assemblages. Further analysis of the data
would add to the number of assemblages that could be included and probably
also identify further ‘large’ weed seeds which would change the emphasis
somewhat. Using Stevens interpretation, in very broad terms, the analysis
suggests that over all the phases, more of the waste is likely to result
from crops stored ‘uncleaned’ i.e. as sheaves or partially threshed ears,
rather than from clean grain or semi cleaned spikelets and that waste
from a number of processing stages may be represented. There is a little
more indication from phase 3 of clean grain or semi-cleaned spikelets.
A potential problem with this (and other models) is that,
inevitably, plants which may or may not have been growing as arable weeds
(such as some damp ground and grassland taxa) will be included in the
analysis and all or some of them may have originated from other activities
and circumstances, such as roofing or flooring debris. A further problem
with all the models is that they cannot take into account that chaff and
/ or stable waste such as straw could have been present on the site from
the outset, but used as fuel or simply burnt deliberately to dispose of
it. With Stevens’s model, if this had taken place, interpretation of crops
stored as sheaves or partially threshed ears could actually be the result
of deliberate burning of chaff as fuel. These
qualifications must be borne in mind when exploring Stevens’ model.
One approach to the use of models is to use them to develop
a hypothesis about possible status and activities, which can then be considered
in relation to all the other forms of bioarchaeological data from a site.
This emphasises the importance of a multidisciplinary approach to bioarchaeological
studies. At Claydon Pike, we are fortunate to have waterlogged preservation
of plant macrofossils and insects, as well as animal bones. The importance
of management of wet grassland at Claydon Pike is well demonstrated by
these studies. It still remains the case as Jones (1985) originally postulated
for the Middle Iron Age, that pastoralism, rather than arable is likely
to have been the main emphasis of local agriculture with semi-cleaned
crops brought in, even if only from a short distance away, necessitating
some processing in the form of dehusking and cleaning to remove chaff
and smaller weed seeds. The crops might well have been in sheaf form at
times, or straw may have been supplied separately as required. This does
not exclude the possibility that small-scale arable plots were also cultivated
on occasion at the settlements, with additional supplies brought in from
outside suppliers when needed. Some of the damp ground plants so often
noted above as possibly originating from animal fodder or even roofing
waste, could have grown on the edges of small plots at Claydon Pike.
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Acknowledgements
We are very grateful to Ann Perry for her work on the Middle
Iron Age macrofossils, and Mark Robinson for assistance with the identification
of some seeds and Gill Campbell and Mark Robinson for helpful comments
on an earlier version of this report. Sheila kindly reformatted the tables.
Top of Page
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