yams on the loose

i stopped by campus after work to drop a couple of things off and to plant the other half of my government potatoes...when i got to looking around the garden i noticed a yam plant had sprung up among the jerusalem artichokes ( second photo ) which are doing well with a bit of rain ad a warm day yesterday ( third photo )...both plants are pretty hardy critters ( the vines form the yam tubers i left in the ground are between twelve and twenty-four inches long now...they are dark and unfortunately blend into the background..the photos i took don't do them justice so i will leave that for a hopefully better shot later )...but the yam in the photo with the sunchokes is one that has grown form an aerial bulb that obviously got by e last autumn...i believe i will leave it be but i'm not sanguine about its chances...it won't have the root system or energy to vine they way the established plants will and the jerusalem artichokes, once they get going, will produce so much shade underneath themselves that they are pretty much self mulching...no weed, or possibly even an aggressive chinese yam, stands much of a chance of establishing itself there...more on this as it goes along...the bottom photo is of zea diploperennis...tell me teosinte doesn't look like maize and i won't believe you...absolutely has to be an ancestor ( or at least one of them depending on who you believe in the corn wars...and no, i am not inviting a debate...no iltus/eubanks comments, please...i will delete them )...so far so good...looking for potatoes soon.