The tulip is a cup-shaped flower originally from Persia, and brought to Europe in the 16th Century; though it was cultivated in many countries, its strongest association is with Holland [EB XXVII:366]. Because of its late introduction to Europe, it’s not surprising that no examples of tulips have been found in period armory.
Like most cup-shaped flowers, the tulip is shown in profile by Society default. The petals should be shown opened: the use of the tulip bud, like the rose bud, is not permitted. The illustration shows a tulip slipped and leaved; it’s taken from Conrad Gesner’s De Hortis Germaniae Liber Recens, 1561. See also iris, lily.
Dai of the Tulips bears: Argent, a tulip gules slipped and leaved vert.
Anna de Brabant bears: Per saltire argent and Or, a tulip flower sable.
Beatrix van der See bears: Per fess wavy vert and barry wavy argent and azure, in chief three tulips Or.