Leaf area is one of the main characteristics used to evaluate plant growth. This work aimed to determine a mathematical equation to estimate the leaf area of Synedrellopsis grisebachii, an important weed in Brazil, using the linear measures of the leaf blade. Length (L), width (W) and real leaf area (LA)of two hundred leaves were measured. LA and L×W data were submitted to linear regression analysis, adjusting a mathematical equation to estimate the leaf area of the species. The correlation between the real and estimated leaf area values was significant. Thus, the leaf area of S. grisebachii may be estimated through the equation LA = 0.730829(L×W).
straggler daisy; biometry; growth; mathematical equation