Abstract:Marrubium vulgare (Labiatae) is a perennial plant,of which its dispersal unit is mainly composed of synaptospermy and seed.Our aim was to determine the morphological,dispersal behavior and germination characteristics of synaptospermy and seed,as well as discuss the ecological significance of appendage and the adaptive strategy of varied environment.Main results are as follows:(1)Synaptospermy envelops seeds in appendage,whose mass is larger than seed;the function of addpendage not only can protect seed from the mechanical damage,but also stay away form predators.(2)In natural habitat,synaptospermy could spread to a long distance easily by the wind.Indoor experiments indicate that synaptospemry spent more time than seed to landing,and had greater ability of spreading;synaptospermy is a kind of adaptive strategy of dalayed spread.The appendage is the key factor that lead to the difference of the spread ability and distance,which supports “Alternate” hypothesis.(3)There are no differences in vigor,germination percentage and germination rate (P>0.05) of synaptospermy and seed,but the water absorption rate of synaptospermy was higher than that of seed.This indicates that the appendage enable the seed to carry more water and retain it longer;the germination of synaptospermy belongs to random germination,which do not have position effect.Only part of the seeds germinated in one season,which is consistent with the intermittent germination characteristic.This characteristic can avoid the risk of destruction of population effectively.These results suggest that the morphological characteristic and the germination behavior of the dispersal unit are lower of perennial,which is related to the importance of the survival of the population.The mother plant of perennial can occupy original habitat for a long-term,keep the number of the individual of population,and the main function of appendage is spreading.