Arabidopsis

Arabidopsis is a model plant for genetics research that demonstrates size-dependent maturity. It flowers after producing approximately 10 leaves, regardless of whether that takes 4 weeks (full light) or 8 weeks (poor light). The plant measures developmental stage (accumulated photosynthetic capacity), not chronological age.

This shows that reproductive transition is triggered by resource accumulation rather than time passage - once sufficient energy production capacity exists (10 leaves), flowering is triggered.