Étude biomathématique du nombre de glandes peltées des feuilles de Mentha ×piperita
The enumeration of peltate glands on Mentha ×piperata leaves was carried out with respect to the date of leaf initiation and the state of its development. For this purpose, observations were made using scanning electron microscopy associated with a mathematical method based on a precise description of gland dispersal on the leaf blade surface. The number of glands can thus be estimated by using only a few photographs of the foliar region located at 2/5 of the leaf length, measuring from the base. The analyses demonstrate a consistency in the number of peltate glands for a given foliar verticil, when the leaf height is equal to or greater than 10 mm. Furthermore, these analyses indicate that the number of peltate glands vary as a function of the level of the foliar verticil. This number increases progressively in verticils 1 to 10, stabilizes, and then decreases in the last verticils produced. This reduction may originate in the meristematic activity that is gradually oriented towards efflorescence. Key words: Mentha, glandular trichomes, enumeration, spatial distribution, leaves, scanning electron microscopy. [Journal translation]