I like heli's elegant shape. Can I grow it together with my highlander nepenthese? The humidity around my highlander nepenthese pots is about 40% during the noon, and 60%-70% during other daytime, and 80%-90% during the nighttime. Temperature is 80 F during the daytime and 60F during the nighttime. Can receive about 3 hours of direct sunlight in the morning and 2 hours of direct sunlight in the evening, and indirect bright shade during other daytime.
If you do want to try, start out with a relatively cheap species that adapts more easily (Heliamphora nutans, H. minor) and acclimate it to lower humidity. Definitely, they will enjoy the temperature swings that H/L Neps get, but the humidity may be a factor you don't want to overlook.
You can try placing the plant in your greenhouse, but with a cover on top to maintain a high humidity level. Dr. Barry Rice describes a cheap Bottle Terrarium which sounds perfect for your situation. Over the course of days or weeks, lower the humidity inside of the terrarium, until the plant is acclimated to your conditions. Beware, though - you'll probably lose some leaves in this process, but if the plant lives, it will replace them with more.
Thank you for your suggestions. I finally bought one H.minor. And the lowest humidity during the daytime is around 60%. But the daytime temperature may achieve 85F during a short time. I hope this is not a big problem to it.
Thank you, Jeff. The temperature is of the summer time. In Fall, Winter, and Spring the night temperature will be down to 55F - 50F. Hope my minor can survive the summer. But I may buy a hybrid of heterodoxa if I could not let the H.minor grow well.