Answer: Qiao Ben or shrub, evergreen or deciduous, single leaf, entire or divided. Flowers are unisexual, often the same plant, the male flowers are often arranged in catkins, the female flowers are in dichotomous cymes, and there are carpules formed by involucres outside. The carpules are arranged in various ways, with appendages on them, which are spiny or scaly, spiral or annular. There are 4 ~ 8 perianth, 4 ~ 20 stamens, and the pollen is often three-furrowed. The ovary is inferior, 3-6 locules, and the style stigma is divided. When the fruit is in fruit, the husk completely or half surrounds the fruit, and the fruit often contains 1 seeds, and the cotyledons of the seeds are thick, powdery or oily. Five common undergraduate plants are Castanea mollissima, Cyclobalanopsis glauca, Quercus microphylla, Quercus variabilis and Nicotiana tabacum.