Asplenium rhizophyllum one collection on sandstone in the Shawnee Hills of Illinois. A triploid hybrid between walking fern and Tutwiler's spleenwort was accidentally produced in culture. A similar plant collected from limestone in Shepherdstown, West Virginia could have originated from the same parents, from an unreduced (diploid) gametophyte of Scott's spleenwort crossed with walking fern, or from an unreduced walking fern gametophyte crossed with ebony spleenwort. In 1813, Henry Muhlenberg listed lobed spleenwort as "Asplenium rhizophyllum" var. "pinnatifidum", although he did not provide a description distinguishing the variety from the typical species. It was described as the species "A. pinnatifidum" by Thomas
Type A (artist collective) Cantz published a monograph featuring this collaboration with the IMA in September 2009. From 2009 to 2011 Type A embarked on two projects exploring fear, safety and authority: "Barrier" (2009) and "Trigger" (2011). "Barrier" is a large scale concrete sculpture installation recreating Jersey highway barriers and "Trigger" explores America’s obsession with guns. For "Trigger," Type A created a series of photographs which are printed and sold as shooting targets by Law Enforcement Targets Inc. With this project they practice what they call "Interpropriation" or “the act of interjecting themselves and actively participating in cultures outside the art world.” In 2012