credit card: a card (usually plastic) that assures a seller that the person using it has a satisfactory credit rating and that the issuer will see to it that the seller receives payment for the merchandise delivered
positive identification: evidence proving that you are who you say you are; evidence establishing that you are among the group of people already known to the system; recognition by the system leads to acceptance
arabidopsis lyrata: a small noninvasive cross-pollinating plant with white flowers; closely related to Arabidopsis thaliana