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中国豆科植物网络分类研究平台

Betulaceae 桦木科分族分属检索表

1.雄花单生于每一苞鳞的腋间,无花被;雌花具花被;果为小坚果或坚果,连同果苞排列为总状或头状
  …..........................................................................................................................1. 榛族  Coryleae Ascherson
2.果序簇生呈头状;花粉粒之孔不显著突出,外壁较厚
  3.果为坚果,大部或全部为果苞所包;果苞钟状或管状;雄蕊花药的药室分离,顶端具簇生毛..….........
    ..............................................................................................................................................2. 榛属  Corylus L.
  3.果为小坚果,全部为果苞所包;果苞囊状;雄蕊花药的药室不分离,顶端无毛................................…
    ...................................................................................................................…2. 虎榛子属  Ostryopsis Decne
2.果序为总状;花粉粒之孔显明突出,外壁较薄
  4.果苞叶状,革质或纸质,扁平,三裂或二裂,不完全包裹小坚果.................3. 鹅耳l枥属  Carpinus L.
    4.果苞囊状,膜质,完全包裹小坚果..............................................................……4. 铁木属  Ostrya Scop.
1.雄花2—6朵生于每一苞鳞的腋间,有4枚膜质的花被;雌花无花被;果为具翅的小坚果,连同果苞排
   列为球果状或穗状.......................................................................…2. 桦木族  Betuleae (Doll) Ascherson
  5.果苞木质,宿存,具5裂片,每1果苞内具2枚小坚果;果序呈球果状;雄蕊4枚;花粉粒通常具4—5
     孔,外壁具明显的带状加厚......................................................................................5.桤木属  Alnus Mill.
  5.果苞革质,成熟后脱落,具3裂片,每1果苞内具3枚小坚果;果序呈穗状;雄蕊2枚;花粉粒通常具
     3孔,外壁无明显带状加厚......................................................................................……6.桦木属  Betula L.

星期三, 2013-12-25 10:54 -- bob59
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Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith