I noticed something cool today. I am rooting this Hoya polyneura. The support stake was not tall enough, and the top of the stem happened to bend, backward, with the leaf undersides facing almost perfectly up. I did not think anything urgent of it, so I just let it be (lazy, I know). So, a new pair of leaves comes out, and they face the light!!! And there is no hint of a twist in the stem or in the petioles of any kind at all! Aren't these things amazing - orienting the new coming out leaves with their photosynthesizing surfaces to where the light is, right from the get-go!