(bottom, left) In a pineapple, a random primordium (n, grey) has some neighbors. Concider unit n and each of the upper neighbors (yellow, magenta and cyan).
(top) Skin, virtually unwrapped.

Connect the grey with the cyan unit, and extend to both sides to get a chain. You may count 8 cyan chains, or parastichies. Furthermore, there are 13 yellow, and 21 magenta ones.

(bottom, right) If you permit jumps, you might define 5 green chains, virtually 3, 2, and even 1, the generative helix. Within each of f chains, neighbours have ordinals with difference f.
Note, that primordial numbers indicate the theoretical point in time of arising of primordia during the development of the pattern. Each of the primordia is part of the generative helix.