5 out of 5 stars. Oxalis oks-AL-iss Info Species. Good Luck Plant Iron Cross Oxalis Tetraphylla Plants Inside Garden Wood Sorrel For a start is has the attractive common names of the Good Luck Plant or Lucky Clover. Oxalis tetraphylla iron cross . One of the common names is also Iron Cross because that name became what it was called by people passing it around. In spring to summer it bears pink funnel-shaped flowers. Exceptionally rewarding Oxalis tetraphylla Iron Cross Good Luck Plant is a bulbous perennial forming a lush mound of rich green leaves composed of 4 heart-shaped leaflets each with a dark purplish blotch at its base. Just the mention of Oxalis conjours up visions of invasive weed problems. Iron Cross Shamrock Bulbs - 10 Bulbs to Plant - Iron Cross Shamrocks - Fast Growing Year Round Color Indoors or Outdoors - Oxalis Shamrock Bulbs - Ships from Iowa Made in USA. In spring when new. The foiage is also striking with a dark purple cross on the 4 heart sh...