Ueca
2017年08月04日, 975人气
It has gained a nice upward-curving shape from being in the sun. Also, a pup is emerging from underneath.
meriunkat赞了
共1条评论
Ueca
2017-08-08
0
I've read up on a plausible explanation for this: A compound in plants called auxin, which triggers a plant's tissue growth, tends to move away from the sun. Since it ends up moving to the bottom of a leaf away from the sun, there is eventually more plant tissue growing from the bottom than the top, which causes the leaf to curl upwards.
I think this also explains etiolation. The auxin occurs all over the plant since there is no sun to repel it, and thus the entire stem elongates.
