Many discoveries have been made recently concerning prehistoric agriculture in
North America.  Gayle Fritz's recent work has shown that the cushaw squash (<i>
Cucurbita argyrosperma</i>) was part of the native crop complex before 1000
A.D. in the eastern Woodlands.  It had previously been considered a
Southwestern/Mesoamerican domesticate brought to the midwest by the
Spaniards.<br>
See:
<pre>Fritz, Gayle J.
   1994   Precolumbian <i>Cucurbita argyrosperma </i>ssp. <i>argyrosperma</i> in the
     Eastern Woodlands of North America.  <b>Economic Botany</b>48(3):280-292.
</pre>

<center> <img src="cushaw1.jpg"> <font size=-1><br> The distinctive <i>C.
argyrosperma</i> plant is depicted in Birger Figurine from Cahokia (left);
remains of the same plant from Ozark Rockshelter in NW Arkansas, ca. 1450
A.D.</font></center> <hr> <p> She is convinced that knotweed (<i>Polygonum
erectum</i>) was also a prehistoric Midwestern crop, although it is not yet
clear if this plant was fully domesticated.<p>

<center>
<img src="sem1.jpg">
<font size=-1>
<br>
S.E.M. image of a <i>P. erectum</i> achene from the Spiro Site, Oklahoma, ca. 800
B.P.
</font>
</center>