Nhu wrote, >Alstroemeria and Bomarea are relatives, they share a common ancestor. >Bomarea stems climb on other plants and if you look closely they actually >twist their leaves so that the leaves face the sun (I went out to look at >my plant just now and it did exactly that!). As a result, some of the >leaves will be resupinate (twisted), others will be non-resupinate >(regular). This may be the case with Alstroemeria too, but they don't climb >and the chances of them falling over isn't too great. Alstroemeria species are varied in size and growth habit, and although they have no active climbing mechanism such as grasping tendrils and petioles or twining scapes, in nature some of the larger ones grow among shrubs and ascend through the shrubs, leaning on them (scandent). I have seen Alstroemeria aurea emerging from a thicket of introduced Himalayan blackberry in Chile at a height almost 2 meters, although A. aurea more typically grows in woodland and open hillsides and is shorter. The flowering stems, which have more scale-like leaves, usually are stiffer and longer than the sterile, leafy stems, and thus better able to get the flowers up where pollinators (which include hummingbirds) will be attracted to them. In species where the leaves are resupinate, this twisting sometimes is at the base and sometimes more toward the mid part of the leaf. It's a diagnostic feature (if we can regress to morphology!). I don't think it changes depending on the site where the plant is growing. The reverse of the leaf, which turns upward when the leaf is resupinate, tends to have a lighter appearance than the upper surface; I think this is from very short, fine hairs. Would this interact with climatic factors, such as high insolation and drought? Jane McGary Portland, Oregon, USA