Rubus spp.

Blackberry, raspberry, dewberry, bramble

Rosaceae

      
The common blackberry, raspberry, and dewberry are well-known plants prized for their sweet, fleshy fruit.

 

Description

       Rubus spp. nutlets or achenes generally have an ovate or half-circular shape. One side is usually more or less straight, while the rest is curved. Most species share a distinctive reticulated surface pattern on the endocarp with a straight, smooth “seam” around the perimeter of the seed. The surface patterning appears as a series of irregularly shaped cells separated by high ridges. This pattern makes identification of even fragments of “seeds” possible. However, although many species of Rubus share this surface pattern, a few species, like Rubus acaulis and Rubus chaemorus, have the same overall seed shape but smooth surfaces. Because of the similarity in seed morphology, it would be very difficult, if not impossible to distinguish a seed to the species level. (See Figure. 1)

       There is a true inner seed under the relatively thick (approximately .3 mm) true endocarp. On rare occasions, the endocarp could break releasing or exposing the seed. This seed is plump, ovate and with a smooth seedcoat. (See Figure. 2)

 

Archaeological Distribution

       Like the modern distribution of the plant, the distribution of Rubus spp. seeds in the archaeological record is widespread. Rubus spp. seeds have been identified from archaeological sites throughout the Midwest. These sites include Cahokia Mounds in the Mississippi Valley (Lopinot 1991), the Icehouse Bottom Site (Cridlebaugh 1981), the Carrier Mills site in central Illinois (Lopinot 1982), the Rhoad and Olin sites in Illinois, and Utz and King Hill sites in Missouri (Cutler and Blake 1976). At the Smiling Dan site, a Middle Woodland site in the Illinois River Valley, Asch and Asch (1985:358) found 29 Rubus spp. seeds. Rubus spp. seeds have also been found in the Toltec Mounds site in Arkansas (Fritz and Powell 1998:135), and in Copple Mound at the Spiro site in Oklahoma (Fritz 1989).

       When Rubus spp. seeds are found in archaeological context, usually only a few are found at a time. Some archaeologists would dismiss the presence of only one or two seeds as implying that the Rubus spp. fruits were of little importance (Lopinot 1982:765). In the report on the Cahokia Mounds ICT-II excavations, however, Lopinot (1991:91) pointed out that the small Rubus spp. seeds are typically consumed with the fruit and “even a limited presence could signify that they were frequently exploited and consumed.”

       A very important site in the Midwest where Rubus spp. seeds have been found is Salts Cave in Kentucky. Yarnell found Rubus spp. seeds in two paleofeces from the cave. In one paleofecal specimen, Rubus spp. was found in “moderate abundance” (440 seeds) and in the other in “scanty abundance” (180 seeds) (Yarnell 1969:42-43,46). The high number of seeds in this fecal material is a graphic demonstration that while it is rare to find more than a few Rubus seeds in most archaeological contexts, it could partially be because most of the seeds were being consumed and deposited in fecal matter. At the same time, however, the presence of Rubus in only two specimens indicates that it was probably only eaten in large quantities for brief periods of the year, usually mid to late summer, when the fruits were most abundant. For this reason Yarnell uses Rubus and strawberries as seasonal indicators to argue that maygrass (Phalaris caroliniana) was used mostly when it was most abundant (late spring to midsummer) and not stored (Yarnell 1969:47).

The Modern Plant and Its Distribution

       Fairly common perennial plants, thirteen species of Rubus native to North America are found in southern Illinois (Lopinot 1982:765). The plants are typically a group of canes sprouting from a common root system. The canes are biennial. During the first year of growth they produce only leaves, but in the second year they produce flowers and fruit. The canes, which tend to be semi-erect, arching, sprawling, or trailing, can become quite tall and are usually covered in throns. The fleshy fruits are compound drupes, red to purplish-black in color, of varying sweetness and size. Identification to species can be quite difficult and requires the collection of both vegetative and flower and fruiting stalks (Steyermark 1963:834-842; see Figure. 3).

       Rubus spp. often grow on the edges of fields or roads, in thickets, forests, meadow, prairies, or abandoned fields (Steyermark 1963; Lopinot 1982:765; Phillips 1979:25). They typically flower between May and June. Fruits are generally ripe and ready for collection in June or July to August (Steyermark 1963:834-842). Ranges vary by species but generally cover most of eastern North America. The northern border of most species is in Quebec or Maine. The southern border can extend as far as Florida or Texas, although some species are found no farther south than Virginia, Kentucky, and Missouri, or northern Arkansas, Alabama, and Georgia. From the east coast, the range of most eastern Rubus species typically extends no farther west than Oklahoma.

 

Discussion

       The sweet, fleshy fruit of blackberries and raspberries are easily collected in large quantities in late summer if one is careful of the multitude of thorns on the canes. The fruit can be eaten fresh or dried and saved for later. In modern times, blackberries and raspberries are often made into an assortment of pies, jellies, jams, syrups, wines, liqueurs, puddings, cakes, cobblers, etc. The young cane sprouts are also edible when peeled (Phillips 1979:23). Young leaves and sometimes root bark are sometimes made into tea (Phillips 1979:24,27; King 1984:157). There are also a number of ethnographically-documented medical uses for Rubus species. Teas or other concoctions made from the roots of several species have been used to treat diarrhea, a variety of digestive troubles, sore eyes, tuberculosis, and female troubles (King 1984:157).

 

References

Asch, D. L. and N. B. Asch

    1985   Archeobotany. In Smiling Dan: Structure and Function at a Middle Woodland Settlement in
            the Illinois Valley edited by B. D. Stafford and M. B. Sant, pp. 327-400. Kampsville
            Archaeological Center Research Series Vol. 2. Center for American Archaeology, Kampsville
            Archaeological Center: Kampsville, Illinois.

Cridlebaugh, P. A.

    1981   The Icehouse Bottom Site (40MR23) 1977 Excavations. Univ. of Tennessee, Dept. of
            Anthropology Report of Investigations #35. Tennessee Valley Authority Publication in
            Anthropology #34. Tennessee Valley Authority, Chattanooga.

Cutler, H. C., and L. W. Blake

    1976   Plants from Archaeological Sites East of the Rockies. Missouri Archaeological Society, 15
            Switzler Hall, Univ. of Missouri in Columbia, Missouri 65201. Printed in microfiche L.C. No.
            76-49422 (Corrected and updated version of the 1973 edition.)
Fritz, G. J.
    1989   Evidence of Plant Use from Copple Mound at the Spiro Site. In Contributions to Spiro
            Archaeology: Mound Excavations and Regional Perspectives, edited by J. D. Rogers, D. G.
            Wyckoff, and D. L. Peterson, pp. 65-87. Oklahoma Archaeological Survey, Studies in
            Oklahoma Past 16. Norman.
Fritz, G. and G. Powell
    1998   Seeds, Plants, and Cultigens. In Toltec Mounds and Plum Bauou Culture: Mound D
            Excavations, by M. A. Rolingson, pp. 135-137. Arkansas Archeological Survey Research
            Series 54. Fayetteville.

King, F. B.

    1984   Plants, People, and Paleoecology. Illinois State Museum Scientific Papers, Vol. XX.

Lopinot, N. H.

    1991   Archaeobotanical Remains. In The Archaeology of the Cahokia Mounds ICT0II: Biological
            Remains, pp. 1-253. Illinois Cultural Resources Study No. 13. Illinois Historic Agency,
            Springfield.

    1982   Plant Macroremains and Paleoethnobotanical Implications. In The Carrier Mills
            Archaeological Project edited by B. M. Butler, pp. 671-860. Center for Archaeological
            Investigations Research paper No. 33. Southern Illinois University of Carbondale, Carbondale.

Martin, A. C., and W. D. Barkley

    1961   Seed Identification Manual. University of California Press.

Phillips, J.

    1979   Wild Edibles of Missouri. Edited by B. Prydon.  Missouri Department of Conservation.

Steyermark, J. A.

    1963   Flora of Missouri. Iowa State University Press: Ames, Iowa.

Yarnell, R. A.

    1969   Contents of Human Paleofeces. In The Prehistory of Salts Cave, Kentucky by P. J. Watson.
            Reports of Investigation No. 16. Illinois State Museum: Springfield, Illinois.

Young, J. A.

    1992   Seeds of Woody Plants in North America. Disocorides Press, Portland.

Written by: Kimberly Schaefe