Page 02 – Leaves

Page 02 – Leaves

c. 1940

Fig. 3 . Leaves. A. The leaves of the plant before floral differentiation form a dense rosette which is approximately heart-shaped in longitudinal section (see broken line). The numbered leaves correspond to the leaf form types shown in B. (Approximately 1/24 actual size). B. Outlines of representative leaves from an average plant just befor floral differentiation (i.e., a plant 15 to 16 months old) to show the variation in form. The leaves were removed and numbered in sequence, beginning at the base of the stem with the first green leaf (i.e., the oldest or first formed); this was numbered no. 1. Outlines of leaf nos. 1, 14, 25, and38 represent variations within a group of fully differentiated (i.e. older) leaves. Notice the expanded base and "neck", i.e., the transition zone between the base and the leaf blade proper, in these leaves. Outlines of leaves no. 40, 59, and 74 represent variations within the group of the not fully differentiated (i.e., younger) leaves. Notice the non-expanded base and the absence of a "neck" in the youngest leaves (nos. 59 and 74). See text, pages 9-12, for a description of these leaves. (Reduction of outlines of leaves to 1/6 acutal size.)