A helical spiral may be placed on a surface of revolution of a 2D profile. Simply use Transform > Deform > Twist. An egg profile was used for testing, also a "vase" profile.

Another method is to use Construct > Curve > Isect of a Helicoid with a larger radius than the 2D profile, with the surface of revolution. The Helicoid is created by two rail sweep of a radial line segment, on a Helix rail, and the revolve axis as a rail. The Helix needs to have parameters compatible with the Twist method, which can then result in curves which appear to be the same.

Using method 2 with a variable pitch helix, from the VarPitchHelixExtremes script, can create a variable pitch spiral on the surface of revolution. This may be useful to create pseudo-fibonacci spiral phyllotaxus models. It may be useful to make Onion dome architecture. The VarPitch script seems to be limited to a portion of 1 turn, and I think the Verbose mode has start and end values reversed(?)
VarPitchHelixExtremes script link:
https://moi3d.com/forum/index.php?webtag=MOI&msg=6697.13

The following link uses surface area density of various surfaces of revolution, to create more realistic phyllotaxis models, but the math is difficult...
There are different groupings of perceived spirals, not just a helical spiral.

https://blog.wolfram.com/2011/07/28/how-i-made-wine-glasses-from-sunflowers/

With a Javascript surface integration method, it may be possible to reproduce his spiral groupings on the surfaces.(?)
https://math.stackexchange.com/questions/707268/area-of-a-surface-of-revolution-integration

There are quite a few Finials with spiral patterns.
Some represent artichokes, etc. The agave core seems to have rhombus patterns. On an ovoid, as opposed to a cylinder, the spiral pattern groups seem to get offset. One link said that only one of 27 pineapples had the 3,5,8 patterns, a la hexagon.
I wonder what the "pitches" would be for these various phyllotaxis patterns. Flowers are modified leaves.

- Brian

The Variable pitch parameters were:
Axis Length 10
Start Radius 5
End Radius 5
Initial Pitch 5, or 7.5
Terminal Pitch 32.5 or 40
Some other values yield weird curves...