You species purists will definately want this one as part of your collection. Hedychium flavescens is one of the parents of many modern hybrids. It brings to the mix a tall, fragrant plant with light yellow flowers responsible for many of the pastels in the Hedychium hybrid world. There has been much confusion between this species and one with a similar name - Hedychium flavum. I have distinguished the two by the shape and color of the bracts - H. flavescens with dark colored, wide bracts and H. Flavum with green narrow bracts.
In my garden, H. flavescens grows to a towering 8 ft. tall with dark green tropical-looking foliage and an interesting flower cone of a darker grey-green color. The flowers appear late in the season, pale yellow and fragrant.
I must share with you an amusing story about this plant. A few months ago I was passing by this plant and was perplexed by a strange shaking and bouncing movement. There was no wind at the time so I could not imagine what it was, causing this plant to bob up and down. It turned out it was visited by a hawk moth that got its proboscis stuck in the flower. I finally set it free but had to surgically remove the flower from the moth. You can see a little pictorial of this event at http://www.gingersrus.com/images/moth/
Hedychium flavescens is rated as hardy in zone 7 by Plant Delights, and I know Tony carefully tests his offerings in Raleigh before putting the number on them. Other references I have seen only give it an 8. It is perfectly hardy in my garden, but I can only test to the upper teens here.
The habit is much like H. thyrsiforme, with a leaning or arching growth that some would want to put to the stake. I prefer to let it lean, and simply plant it in a spot that takes advantage of that kind of architecture.
Hedychium flavescens should be planted in part shade, probably will not take full sun as many Hedychiums do. It does need the standard Hedychium soil - rich, moist and organic.