Fig 1. Pictures of some plant organs used in experiments.

(a) leaves. 1 is the leaves of Ginkgo biloba, which is sector, yellow and leathery; 2 is the leaves of Diospyros rhombifolia, which is oval, green and paper-like. (b) Flowers. 1 is the flower of Cercis chinensis, with is raceme and purple; 2 is the flower of Michelia maudiae, which is solitary and white. (c) Fruits. 1 is the fruit of Punica granatum, which is spherical, berry, red and large; 2 is the fruit of Pinus thunbergii, which is oval, cone, green and medium.