If you don't know the spidrons, go to the site of Dániel Erdély, there are fabulous things.




A spidron         is the sum of 2 half-spidrons     




Afterwards I shall arbitrarily call half-spidron of rank 0 the half-spidron above.

We go from an half-spidron to the half-spidron of higher rank by multiplying its dimensions by .
 

                 

    rank 0                            rank 1                                                 rank 2                      rank -1   rank -2

Associating 2 half-spidrons of rank 0 we can obtain :



a spidron of rank 0                    or an "hornflake" of rank 0         





Let us look at an half-spidron closely :        

It  can be breaked up into 3 parts with same area ; the 2 first are the triangles that we used to make the polyiapons ; the third is in fact an hal-spidron of rank -1 : I shall call it head of spidron. 

I call polyspidron every assemblage of several of these 3 forms.


examples :   a tetraspidron                   and a pentaspidron          




The spidron and the "hornflake" of rank 0 are both hexaspidrons.

Let us look closely at the "little" polyspidrons :


So there are 3 monospidrons :           



There are 10 bispidrons :              


The 4 first, above, are bispidrons without head ; they are also biiapons.

                                  
There are 3 bispidrons with 1 head                                   and 3 bispidrons with 2 heads.
The 3 bispidrons with 2 heads are "pure" bispidrons ; they are :
a) an "hornflake" of rank -1          b) a spidron of rank -1         c) a "rolled up" bispidron

There are 41 trispidrons :









12 trispidrons without head or triiapons

12 trispidrons with 1 head



12 trispidrons with 2 heads



5 trispidrons with 3 heads or "pure" trispidrons ; the third is a "rolled up" trispidron

The head of spidron, the rolled up bispidron and the rolled up trispidron together form a node of spidrons :



            positive node           negative node



We need 6 heads of spidron to do a node of  spidrons.

Polyspidrons                                                   Bonvenon