I found a website www.foxearth.org.uk that has documents in East Anglia England. If you search the site for Rison or Ryson or Risen you find documents for a John Rison in the 1580s as a baliff and a William and Thomas Risen in the 1830s winning a ploughing contest as well as a John Risen later in the 1800s accused of stealing rabbit skins. Maybe this is where the Maryland Risens came from?