<textarea name="text"><xsl:value-of select="/root/description"/></textarea>
but when it is parsed, as there is no /root/description element, or it's empty, it comes out like this:
<textarea name="text"/>

This should not happen if the output method was correctly set to HTML.
You should tell something more about your environment. Is the output
of the transformer really a stream?

The parser I am using is the Xalan Java processor.

This invites flames! :-) I don't think Xalan is a parser, nor does
it process Java.