Answer: Queen's tears (Billbergia nutans) is a type of bromeliad. It prefers bright light away from direct sunlight and average room temperatures. Keep the central "vase" filled with water, but water the soil sparingly.
By shamrock you are probably referring to Oxalis. This plant also prefers bright light, but also enjoys some direct sunlight. Keep the soil moist, but not saturated. Cut back on watering after blooming to give the plant a rest period.
I'm sorry, but I'm not sure what plant you are referring to by the name Exotica. If you can post another question via the web site with a detailed description of the plant, we'll try to identify it for you.
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