CHARRED TUBERS : RANUNCULUS FICARIA
Ranunculus ficaria L.
Common Name: Lesser Celandine, Pilewort
Ranunculus ficaria is a small low-growing perennial plant with yellow flowers and dark green inverted heart shaped leaves. The roots form tubers with rounded ends and, on subspecies bulbilifer and ficariiformis, bulbils develop in the leaf axils after the flowering period ends. Ranunculus ficaria flowers in spring and in summer the above ground tissue disappears and the tubers lie dormant until winter when the leaves emerge (Halket 1927). Lesser celandine grows in damp meadows, woods, streambanks, hedgebanks, and lawns throughout the UK, Europe and Western Asia. In the past it was used as a remedy for piles since the tubers were thought to resemble piles and that is where the common name ‘Pilewort’ originates.
Root tubers of Lesser Celandine form at the base of the stem. There can be as many as 20 tubers per plant although on average 7 – 12 tubers per plant is more common (Hather 1993). The tubers can be between 5mm and 8cm long and 5-7mm wide at their widest point (Hather 1993). They tend to swell towards the base of the tuber and form a rounded end.
Ranunculus ficaria tubers have been identified in Mesolithic Hardinxveld-Giessendam Polderweg in the Netherlands (Bakels and van Beurden 2001) and in large quantities at Staosnaig on Colonsay in western Scotland (Mason and Hather 2000; Mithen et al 2001). Remains from the Neolithic have been found at Hekelingen (Bakels 1988) and Warmond Park Klinkenberg (van Beurden and van Waijjen 2006) in the Netherlands, a pit at Mortens Sande 2, Denmark (Robinson and Kempfner 1988), and at Windmill Hill in Wiltshire, UK (Fairbairn 1999). From later sites, Bronze Age tubers were noted at Mile Oak, Sussex. UK (Hather 2000) and in hearths, cooking pits and cultural layers at Ajvide, Denmark (Engelmark and Viklund 1988), in an Iron Age pit at Nettlebank Corpse, Danebury Environs, UK (Campbell 2000), and Dragonby, Humberside. UK (Van der Veen 1996).
In most instances, charred Ranunculus ficaria tubers are interpreted as human foods that have been accidently preserved through cooking or drying. Ranunculus species are known to contain a toxin, protoanemonin, that tastes acrid and burns the throat which necessitates the processing of tubers, either by boiling, roasting or drying, before they can be consumed (Kuhniein and Turner 1991). Ethnographic studies record the Snohomish of Canada cooking Ranunculus roots on hot rocks, then dipping them in whale and seal oil and eating them with salmon eggs (Mithen et al 2001). In Europe, Lesser Celandine tubers are known to have been being cooked and included in salads, in Sweden tubers were eaten after being boiled, dried and then ground into a flour and in eastern Netherlands tubers were cooked or baked and served like potatoes with meat (Mason and Hather 2000). The leaves were also eaten after boiling as a salad to combat scurvy (Mason and Hather 2000). Lesser Celandine tubers have also been used as a cure for piles.
The quantity and ubiquity of tubers found at both Staosnaig in Scotland and Hekelingen in the Netherlands, are taken to indicate the intentional collection and heating of tubers for human consumption (Mason and Hather 2000; Bakels 1988). At both locations the remains were thought to be the discard of over charred tubers rather than in situ remains in roasting pits. At Staosnaig, both tubers and bulbils were identified together with huge quantities of hazelnut shells. The presence of tubers and bulbils at Staosnaig indicates that the Ranunculus ficaria plants were collected in the spring, when both vegetative storage organs would have been present on the plants, and prior to the dying of above ground tissue in summer. The occasional presence of distorted and poorly preserved tubers, suggests that fresh tubers were being charred and provides an additional seasonal marker for occupation at Staosnaig in spring when Lesser Celandine had both tubers and bulbils (Mason and Hather 2000). Collection of tubers could itself have assisted in the spread of Lesser Celandine since digging would have disturbed the ground, fragmented the tubers and encouraged more vegetative propagation (Bond, Davies and Turner 2007).
- Bakels, C. C. (1988) Hekelingen, a Neolithic site in the swamps of the Maas estuary, in: H. Küster (ed.), Der prähistorische Mensch und seine Umwelt, Festschrift U. Körber-Grohne zum 65. Geburtstag, Stuttgart (Forschungen und Berichte zur Vor- und Frühgeschichte in Baden-Württemberg 31), 155-161.
- Bakels, C. C., and L. M. van Beurden. (2001). Archeobotanie. In Archeologie in de Betuweroute Hardinxveld-Giesendam Polderweg een mesolithisch jachtkamp in het rivierengebied (5500–5000 v. Chr.), ed. L. P. Louwe Kooijmans, pp. 325–78. Amersfoort.
- Bond, W., Davies, G., and Turner, R. (2007) The biology and non-chemical control of Lesser Celandine (Ranunculus ficaria L.) HDRA. archived at gardenorgranic.org.uk
- Engelmark, R. and K. Viklund (1988). Förhistorisk "popcorn". Populär Arkeologi 6/2, 11.
- Halket, A. C. (1927) Observations on the Tubercules of Ranunculus ficaria, L. Annals of Botany 41 pp. 731 - 753.
- Mason, S. and Hather, J. (2000). Parenchymatous plant remains. in S. Mithen (ed.) Hunter-gatherer landscape archaeology: The Southern Hebrides Mesolithic Project 1988-98. Vol 2: Archaeological fieldwork on Colonsay, computer modelling, experimental archaeology, and final interpretations. Cambridge (McDonald Institute for Archaeological Research) pp. 415-425.