EDIT

If a PKN has a feature and not a statement it is repeated multiple times for the child alternatives. A better layout is show the feature once and then have a line break and start with the statements of the alternatives.

An example is here but probably this link will change in future:

http://test.e-taxonomy.eu/dataportal/preview/greece_bupleurum/cdm_dataportal/polytomousKey/2e37d588-16c9-4e57-8b77-c33d3a63990a