If you want to start your own Christia obcordatas, you'll need to buy some seeds first. These will germinate easily once sown in warm, bright light.  Sow seeds directly onto the surface of dampened potting mix, cover with plastic wrap, and leave in a warm room until seedlings start to appear. Lift the plastic daily to give it some oxygen and ventilation.  When you're ready to transplant your seedlings outside, use only fresh potting mix and place them into larger pots filled with fresh potting mix. Water thoroughly before placing the pots in a warm and humid location.