Morphological, anatomical, and cytological characters in the lower epidermis of the leaf in Rubiaceae

Abstract

The author establishes twenty four morphological, anatomical, and cytological characters which occur in the lower epidermis of the leaf of the 517 species of Rubiaceae (distributed among 108 genera). He thought it appropriate to draw up two tables showing the ocurrence of these characters. The first table refers to the entire group of species, the second to the genera. The letters of the alphabet indicate the characters investigated. By examining the tables it becomes obvious that the genera Augusta, Bertiera, Chytropsis, and Macrocnemum have the lowest ocurrence of the characters investigated, i.e. 8.33% whereas the genera with the highest occurrence of the characters investigated are the following: Psychotria with 70.83%, Palicourea with 75%, and Rudgea with 79.16%. The characters found least frequently in the species investigated are n (wax in the epidermis in the accessory cells), and m (fatty substances) which occur in 0.58 respectively 1.35% of the species. The most frequently observed characters are b (epidermis with hairs) and j (maroon, brown etc. contents), which occur in 42.74%, respectively 58.86% of the species investigated.