In Section 5.6.1 we started a discussion on Fujita's diagrams. It was stated that many possible sources of errors leading to these diagrams can be identified. They are, for example, Fujita's use of contact parastichies, and the way he determined them from transverse sections and from direct observations, the presence of triple contact points, the number of species he considered, the levels at which the transverse sections were made, the way he measured the divergence angles, the relative ease with which the parastichies can be observed, and the determination of the axis of the plants (see in Section 5.6.2 the discussion on Fig. 5.2). Let us look into these statements.

The absence of distinctions between contact, conspicuous, and visible opposed parastichy pairs, and the presence of a large quantity of such pairs in the same system (see Section 2.2) weighed heavily on the subject of phyllotaxis since its very beginning (see Section 2.1). The lack of a clear understanding of them has indeed created since the 1830s a long history of confusion and obstruction, inducing serious errors in the conclusions of the investigators. These clarifying notions were introduced by Adler (1974, 1977a) after Fujita's papers were published.

The notion of contact parastichies, used by Fujita (1938, 1939) to determine which pattern was under observation, is intuitively good to some extent.