Seed number is often used as a measure of fitness; however, situations exist where there is a discrepancy in the relationship between seed number and fitness In Chapter 1, I identify eight main scenarios in nature where fitness is not well represented by seed count, and review existing empirical research that have used seed count under these specific scenarios. Results suggest that the validity of seed number as a measure of fitness is largely under studied and should be supplemented with alternative metrics to appropriately quantify fitness. In Chapter 2, I use the monocarpic herbaceous plant Lobelia inflata to assess whether variable seasonal constraints can disrupt the relationship between seed count and fitness under controlled growth chamber conditions. Interestingly, the relative per-seed fitness is 0.774±0.034 under constrained season length conditions; higher total fitness is observed under a constrained season using simple seed count, but not after accounting for seedling viability.