The flower snarks, denoted 
for 
, 7, 9, ..., are a family of graphs
discovered by Isaacs (1975) which are snarks. The construction
for flower snarks may be generalized to all (i.e., not just odd) integer 
. In this work, such graphs are termed flower
graphs.
appears in Scheinerman and Ullman
(2011, p. 96) as an example of a graph with edge
chromatic number and fractional
edge chromatic number (4 and 3, respectively) both integers but not equal.
Flower snarks are unit-distance. They are also maximally nonhamiltonian (Clark and Entringer 1983) as well as platypus graphs.
Precomputed properties of flower snarks are implemented in the Wolfram Language as GraphData[
"Flower", n
].
