This project sought to characterize plant defense investment in the castor bean (Ricinus communis L.), an exotic myrmecophyte in southern California, with respect to life history strategies. Experimental evidence suggests that exotic myrmecophytes can form mutually beneficial associations with exotic ants regardless of the differences in shared evolutionary histories. Castor bean plant investment in defense was evaluated by measuring the area on extra-floral nectary (EFN) glands. Life history strategies may change with respect to plant size and was therefore evaluated in terms of basal stem diameter (<50mm). We hypothesized that smaller and younger castor bean plants would have bigger EFN glands than larger and older plants. We found that EFN gland size was not correlated to castor bean class size. This suggests that in southern California, biotic plant defense is not optimized in castor bean plants. As an r-selected species, the castor bean plant compromises investment in plant defense favoring investment in growth and early reproduction.