Cacti are some of the hardiest plants. They last decades on minimal water.
These markers measure approximately 7/16" (11 mm) long by 1/4" (5 mm) wide, and weigh less than a gram.
They are shown on a 6 mm ring and a 12 mm lobster clasp. The 6 mm ring comfortably fits knitting needles size US4 and smaller. The 8 mm ring comfortably fits knitting needles size US6 and smaller.