Sunflowers placed into the world in snapshots 14w28b or prior uproot themselves or drop when upgrading directly to 14w30c. (Just my speculation, this bug possibly resulted from the fix to MC-57992)

Steps to Reproduce:

• Plant a 5x5 grid of sunflowers in 14w28b (Figure 1)
• Upgrade to 14w30c and observe the condition of the sunflowers then (Figure 2)

For me, all 25 sunflowers uprooted in the experiment (Figure 3), though the behaviour seems to be fairly inconsistent as in other cases, some sunflowers were left with only half their stem (i.e. flower texture missing) and in very rare cases, the sunflowers remained intact.