Branch of a Six Months Old Chestnut
The picture shows the way in which the chestnut burs form in relation to the catkins. Many of the hybrid chestnuts have the peculiar quality of putting forth blossoms at almost every season, so that flower buds and blossoms and mature fruit, may be found on the same branch.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 11 Chapter 4