Fig. 1From: Transcriptomic and microstructural analyses in Liriodendron tulipifera Linn. reveal candidate genes involved in nectary development and nectar secretionThe development process of petals in Liriodendron. S1: stage1, all floral organs elongated; S2: stage2, the petal was over twice the size of the petal in stage 1 and the base was fleshy and white; S3: stage3, each petal present three colors obviously, with green on the top, yellow in the middle part, and white at base; S4: stage4, the petal color changed from yellow to orange in the middle part; S5: stage 5, the color of the middle part deepened; S6: stage 6, the petal fall; n: nectar; p: pllenBack to article page