▁germ ination ▁is ▁almost ▁entirely ▁dependent ▁upon ▁a ▁combination ▁of ▁an a er ob ic ▁conditions ▁and ▁light . ▁This ▁strategy ▁helps ▁the ▁plant ▁begin ▁germ ination ▁when ▁pool ▁bas ins ▁are ▁filled ▁with ▁water . ▁In ▁years ▁of ▁low ▁precip itation , ▁the ▁soil ▁sub sur face ▁is ▁likely ▁to ▁be ▁an a er ob ic ▁or ▁hy po xic , ▁and ▁in hib it ▁germ ination . ▁ ▁Tu ctor ia ▁gre ene i ▁is ▁of ▁high ▁conservation ▁concern ▁in ▁California , ▁as ▁v ernal ▁pool ▁systems ▁are ▁in ▁decl ine ▁due ▁to ▁agricult ural ▁development ▁and ▁urban ▁expansion . ▁ ▁See ▁also ▁List ▁of ▁Po aceae ▁gener a ▁ ▁References ▁ ▁External ▁links ▁Gr ass base ▁- ▁The ▁World ▁Online ▁Gr ass ▁Flora ▁ ▁Category : Ch lor ido ide ae ▁Category : B unch gr ass es ▁of ▁North ▁America ▁Category : Native ▁grass es ▁of ▁California ▁Category : Gr ass es ▁of ▁Mexico ▁Category : Po aceae ▁gener a <0x0A> </s> ▁The ▁B ust ▁of ▁Francesco ▁I ▁d ' E ste ▁is ▁a ▁mar ble ▁portrait ▁b ust ▁by ▁the ▁Italian ▁sculpt or ▁Gian ▁Lorenzo ▁Bern ini . ▁Comple ted ▁in ▁ 1 6 5 2 , ▁the ▁work ▁dep ict s ▁Francesco ▁I ▁d ' E ste , ▁Duke ▁of ▁Mod ena . ▁It ▁is ▁in ▁the ▁Museo ▁Est ense , ▁Mod ena , ▁Italy . ▁The ▁noble ▁yet ▁det ached ▁expression ▁of ▁the ▁face , ▁the ▁extensive ▁dra per y ▁and ▁the ▁lav ish ▁lo cks