13-rayed

Updated: August 2, 2026

Next year I sowed a new mixture in order to isolate the reputed pure grandiflorum type. During the beginning of the flowering period I ruthlessly threw away all plants displaying less than 21 rays in the first or terminal head. But this selection was not to be considered as complete, because the 13-rayed race may eventually transgress its boundary and come over to the 21 and more.

Hugo de Vries - Species and Varieties, Their Origin by Mutation

The seeds which are offered for sale usually contain a mixture of both forms and their hybrids. So I had to isolate the pure types from this mixture and to ascertain their constancy and mutual independency. To this end I isolated from the mixture first the 13-rayed, and afterwards the 21-rayed types.

Hugo de Vries - Species and Varieties, Their Origin by Mutation