Mishnah Kil'ayim 1:4 mentions different pairs of trees, such as the peach tree (Prunus persica) and the almond tree (Amygdalus communis; syn. Prunus amygdalus), and the trees known in Hebrew as shizǝfīn (Ziziphus jujuba) and rīmmīn (Ziziphus spina-christi), saying that "although they are like each other, they are considered diverse kinds (kil'ayim)." On the identification of these species of trees, see: Zohar Amar, Flora and Fauna in Maimonides' Teachings, Kfar Darom (2015), pp. 133, 150, 157, 161. OCLC783455868.