Just an update to say I couldn't find an illustration of this shape in my books, however Decelle, in Opalescenece Le Verre Moulée des Annees 1920-30, does mention an Etling 'Assiette aux eucalyptus' which likely refers to this pattern. He doesn't attribute it to a specific designer, but many of the plant and floral designs produced for Etling were created by Georges Béal.