3.3. Seed longevity
Seed germination percentage of T. achyrostachys (2= 26.2 formlinear term and 2= 23.3 for the quadratic term; P < 0.001) and T. schiedeana (2= 27.6 and 2= 18.9 for the linear and quadratic terms, respectively; P < 0.001) showed a quadratic decline (Fig. 4);while in T. caput-medusae (2= 56.1; P < 0.0001 for the linear term and 2= 1.2; P = 0.26 for the quadratic term) and T. circinnatioides(2= 61.0; P < 0.0001 for the linear term and 2= 0.2; P = 0.69 forthe quadratic term), seed germination percentage declined linearly(Fig. 4).