FWIW, and not saying it's relevant in this case, but it is possible for a plant not propagated asexually to be considered a cultivar under the International Code of Nomenclature for Cultivated Plants. As just one example from the code:
"2.12. An assemblage of individual plants grown from seed derived from uncontrolled pollination may form a cultivar when it meets the criteria laid down in Art. 2.3 and when it can be distinguished consistently by one or more characters even though the individual plants of the assemblage may not be genetically uniform."
Some of the examples given under this section are Lavatera 'Ice Cool', Millium effusum 'Aureum', Viola 'Penny Black' - "are cultivars which are propagated from seed".
The criteria in Art. 2.3 referred to in the above is that "A cultivar is an assemblage of plants that (a) has been selected for a particular character or combination of characters (b) is distinct, uniform and stable in these characters, and (c) when propagated by appropriate means, retains those characters..."
