by Robert Connell Clarke
Leaf Traits
Leaf traits vary greatly from strain to strain. In addition to these regularly occurring variations in leaves, there are a number of mutations and possible traits in leaf shape. It may turn out that leaf shape is correlated with other traits in Cannabis. Broad leaflets might be associated with a low calyx-to-leaf ratio and narrow leaflets might be associated with a high calyx-to-leaf ratio. If this is the case, early selection of seedlings by leaflet shape could determine the character of the flowering clusters at harvest. Both compound and webbed leaf variations seem to be hereditary, as are general leaf characteristics. A breeder may wish to develop a unique leaf shape for an ornamental strain or increase leaf yield for pulp production.
A peculiar leaf mutation was reported from an F1 Colombian plant in which two leaves on the plant, at the time of flowering, developed floral clusters of 5-10 pistillate calyxes at the intersection of the leaflet array and the petiole attachment, on the adaxial (top) side of the leaf. One of these clusters developed a partial staminate flower but fertilization was unsuccessful. It is unknown if this mutation is hereditary. From Afghanistan, another example has been observed with several small floral clusters along the petioles of many of the large primary leaves.