Prunus subg. Prunus is a
subgenus of Prunus. This subgenus includes
plums,
apricots and
bush cherries. Some species conventionally included in Prunus subg. Amygdalus are clustered with plum/apricot species according to
molecular phylogenetic studies.[1][2] Shi et al. (2013) has incorporated subg. Amygdalus into subg. Prunus, thereby including
almonds and
peaches in this subgenus.[1] The species in this subgenus have solitary flowers or 2–3 in a fascicle.[1][3]
Sections according to Shi et al. (2013)
Shi et al. (2013) divide subg. Prunus into seven sections: sect. Amygdalus, sect. Armeniaca, sect. Emplectocladus, sect. Microcerasus, sect. Persicae, sect. Prunocerasus and sect. Prunus. They form three clades. The basal clade is sect. Emplectocladus which is sometimes treated as a subgenus. The other two clades are the Amygdalus-Persicae clade (sometimes treated as subg. Amygdalus) and the Armeniaca-Microcerasus-Prunocerasus-Prunus clade (subg. Prunus in a narrow sense).[1]
Sect. Emplectocladus
Prunus sect. Emplectocladus (Torr.) A.Gray is the
sister group to all the other species in this subgenus,[1] and sometimes treated as a distinct subgenus, Prunus subg. Emplectocladus (Torr.) S.C.Mason. It includes six
New World species.[4][5]
Prunus sect. Amygdalus (L.) Benth. & Hook.f. and Prunus sect. Persica (Mill.) Nakai[a] sometimes constitute Prunus subg. Amygdalus (L.) Focke. They form a monophyletic clade together, but the boundary between them seems not very distinct. A few species, such as
P. spinosissima (thorny almond) and
P. kansuensis (Gansu peach), are clustered in either sect. Amygdalus or sect. Persica in different studies.[2][6] The word "ămygdălus" is Latin for the almond nut.[7]
Species of the following sections were not presented in the results of Shi et al. (2013). Therefore, their relationship with the sections proposed by Shi et al. (2013) is unclear.
Sect. Chamaeamygdalus
Prunus sect. Chamaeamygdalus (Spach) Dippel used to be included in the Amygdalus-Persica clade. However, molecular phylogenetic research indicates that it should be excluded from the Amygdalus-Persica clade.[2] The phylogenetic positions of the species in this section are still uncertain.
Prunus sect. Louiseania (Carrière) Yazbek includes two or three Asian species.[9] Although they are called flowering almond, they are more related to
bush cherries (sect. Microcerasus) and
apricots (sect. Armeniaca).[2][6][10][11][12][13][14][15][16] According to
nuclearphylogenomic analyses, the type species of sect. Louiseania, P. triloba, is embedded in sect. Microcerasus and closely related to the P. prostrata, the type species of sect. Microcerasus. However, in the phylogenetic tree based on
plastid genome, P. triloba together with P. tomentosa (also a member of sect. Microcerasus) and apricots is in a clade that is sister to the core part of sect. Microcerasus.[14][16]
Prunus sect. Penarmeniaca S.C.Mason is the sister group to New World plums, P. texana and probably the Old World species P. tenella.[2] It includes two New World species.[4][17]