Can't create selectmenu dynamically

Consider the example in which we create a selectmenu from javascript:

#!text/html
<script type="text/javascript">

var selhtml = `<select id="sel1">
   <option value="1">Apples</option>
   <option value="2">Orange</option>
   <option value="3">Peach</option>
</select>`

var sel = $(selhtml)
var parent = $("div#mysel")
parent.append(sel.selectmenu())
// or
// sel.selectmenu({appendTo: parent}) 
</script>

This does not work. It wont throw the selectmenu into the dom. This is a problem when a selectmenu is part of a larger javascript component. On this case the parent node may not even exists but we should be able to create the menu in order to attach it at a later point, when the parent is created.