Hello Jim For me there is no doubt that Clusius (written 1592, publised 1601, page 139-140) received seeds too from Busbecq in 1573. He describes in detail that he obtained flowering plants in the 6th 7th and 8th year (repeated on p 143and already stated in 1583 "Austriam Historia"). In his publication of 1576 Clusius writes ((.........))Ex seminibus vero qua fit propagatio, plane (uti dixi) incerto est. Freely translated: (((A bulblet in the axil of the leaf gives the same color as the mother)) Grown from seed the resulting (color) is uncertain. He also mentions droppers , most typically for young seedlings. He also states that seeds is best sown fresh in autumn. He also says that the seedlings often give flowers differing from their parents, in color and in flowering time and so on SO clearly he was experienced in growing tulips from seed. In Chitral it is said by Dasgupta 1985 that T clusiana grows in several colors Lastly I have seen T schrenkii in the wild with 40 % white 40% yellow and 20 % all other colors from pink to red with or without a different colored edge. By the way: no need to explain genetics for me, I am a geneticist.