 A number of other characteristics of B. prionotes can be understood as secondary responses to weak serotiny . For example , winter flowering ensures that seed is ripe by the beginning of the bushfire season ; this is very important for weakly serotinous species , which rely heavily upon the current year 's seed crop . Another example is the deciduous florets of B. prionotes . In strongly serotinous species , the old florets are retained on the cones , where they function as fire fuel , helping to ensure that follicles reach temperatures sufficient to trigger seed release . In B. prionotes , however , seed release is triggered at relatively low temperatures : in one study , 50 % of follicles opened at 265 ° C ( 509 ° F ) , and 90 % opened at 330 ° C ( 626 ° F ) ; in contrast , the closely related but strongly serotinous B. hookeriana required 340 and 500 ° C ( 644 and 932 ° F ) respectively . Floret retention would therefore be to no advantage , and might even prevent seed from escaping spontaneously opened follicles . 
