Wikipedia list 7 different species of Afzelia, one of which is Afzelia Xylocarpa.
http://en.wikipedia.org/wiki/Afzelia
All of the Afzelia species are in the Fabaceae falmily, which also includes all of the Mesquites, Acacias, Carobs, and Tamarinds, all of which produce edible seeds. Also included in the Fabaceae family are peas, peanuts, beans, and lentils.
What you have is more than likely an exceptional piece of what turners normally refer to as XY Afzelia, XYlay Afzelia, or Snakeskin Afzelia. You will probably have a hard time finding a piece with the intense figure you've shown above but there are sources available:
http://www.pennstateind.com/store/wxafzlx.html
http://www.arizonasilhouetteinc.com/cart/index.php?main_page=product_info&cPath=86&products_id=726
http://cgi.ebay.com/Afzelia-Xylay-Pen-Blanks-Intense_W0QQitemZ280134616372QQihZ018QQcategoryZ71234QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
http://www.woodturnerscatalog.com/store/Turning_Materials___Pen_Blanks___Exotic_Pen_Blank___exotic_blank?Args=
(No photo but listed as item 206-9308 Afzilia Lay)
Below is a pen I found in the SOYP forum that appears to be from XY Afzelia:
http://www.penturners.org/forum/topic.asp?TOPIC_ID=22976&SearchTerms=afzelia
Jason