, ▁seed ▁and ▁leaf ▁characteristics . ▁ ▁DNA ▁ph y log eny ▁has ▁shown ▁that ▁species ▁formerly ▁in ▁sub gen us ▁Duc amp op inus ▁are ▁members ▁of ▁sub gen us ▁St ro bus , ▁so ▁Duc amp op inus ▁is ▁no ▁longer ▁used . ▁ ▁The ▁species ▁of ▁sub gen us ▁Duc amp op inus ▁were ▁regarded ▁as ▁intermediate ▁between ▁the ▁other ▁two ▁sub gener a . ▁In ▁the ▁modern ▁classification , ▁they ▁are ▁placed ▁into ▁sub gen us ▁St ro bus , ▁yet ▁they ▁did ▁not ▁fit ▁entirely ▁well ▁in ▁either ▁so ▁they ▁were ▁class ified ▁in ▁a ▁third ▁sub gen us . ▁In ▁ 1 8 8 8 ▁the ▁Californ ian ▁botan ist ▁John ▁Gill ▁Lem mon ▁placed ▁them ▁in ▁sub gen us ▁P inus . ▁In ▁general , ▁this ▁classification ▁emphas ized ▁cone , ▁cone ▁scale , ▁seed , ▁and ▁leaf ▁fasc icle ▁and ▁she ath ▁morph ology , ▁and ▁species ▁in ▁each ▁sub section ▁were ▁usually ▁recogn izable ▁by ▁their ▁general ▁appearance . ▁P ines ▁with ▁one ▁fib ro vas cular ▁bundle ▁per ▁leaf , ▁( the ▁former ▁sub gener a ▁St ro bus ▁and ▁Duc amp op inus ) ▁were ▁known ▁as ▁ha p lo x yl on ▁p ines , ▁while ▁p ines ▁with ▁two ▁fib ro vas cular ▁bund les ▁per ▁leaf , ▁( sub gen us ▁P inus ) ▁were ▁called ▁dip lo x yl on ▁p ines . ▁D ip lo x yl on ▁p ines ▁tend ▁to ▁have ▁harder ▁tim ber ▁and