A study of the morphoanatomical characters of the leaves of Chamaecrista (L.) Moench sect. Apoucouita (Leguminosae-Caesalpinioideae)

Abstract

Little attention has been paid to species of Chamaecrista sect. Apoucouita (Leguminosae-Caesalpinioideae), especially regarding anatomical studies. When only vegetative material is available, the identifi cation of such species may be diffi cult. Additionally, vegetative material of some species of C. sect. Apoucouita may be even harder to identify because they can resemble species of Inga Mill. (Leguminosae-Mimosoideae). Th e present study focused on recognizing morphoanatomical characters of leaves that are taxonomically useful for the species of C. sect. Apoucouita by employing standard anatomical techniques. Th e arrangement of the vascular system in the petiole/rachis, dorsiventral mesophyll, mucilage idioblasts in the epidermis of leafl ets and hypostomatic leaves were some of the characters shared by all species studied. Length of the petiole, position and type of extrafl oral nectaries, leafl et venation, presence and type of papillae on the epidermis of the leafl et blades and sclereids in the mesophyll were some of the characters useful in the distinction of taxa. Th e vascular arrangement of the petiole/rachis is a promising character in the distinction of species of C. sect. Apoucouita and Inga. Based on morphoanatomical data, the taxonomic revision of some species and varieties ascribed to C. sect. Apoucouita is suggested.