酢浆草属5种植物的微形态特征观察

利用光镜和扫描电镜观察了酢浆草属(Oxalis L.)5种植物的叶、花、花粉和部分种子的微形态结构。5种植物叶片上均具有平列型气孔器,外围3~4个不规则表皮细胞;酢浆草(O.corniculata L.)、铜锤草(O.corymbosa DC.)及白花酢浆草(O.acetosella L.)叶片两面均有气孔器,下表皮犹密;紫叶酢浆草(O.triangularis A.St.-Hil.)和山酢浆草(O.griffithii Edgew.et Hook.f.)的气孔器只分布于叶片下表皮。不同种间及长、短雄蕊上的花粉粒大小各异,花粉多呈近球形(酢浆草、白花酢浆草)、长球形(紫叶酢浆草、山酢浆草)或超长球形(铜锤草),极面观为三裂圆形,赤道面大多具3沟,少数4沟,表面具有不规则的穴状或粗网状纹饰,网眼内无或有乳突状突起(铜锤草、紫叶酢浆草)。酢浆草种子较小,表皮纹饰为比较规则的不等边六角形网眼,网眼中间具棱柱状突起,上有钩状附属物;山酢浆草种子较大,表皮粗糙程度低于酢浆草。

Observation of micromorphological characters of five species in Oxalis

The micromorphological characters of leaf,flower,pollen grain and seed of five species in Oxalis L.are observed by using SEM and LM.The leaf epidermis of five species all present paracytic stomata,encircled with 3-4 irregular epidermal cells.And the stomata occur on both sides of leaf epidermis of O.corniculata L.,O.corymbosa DC.and O.acetosella L.,especially in lower epidermis,whereas that only occur on lower epidermis of O.triangularis A.St.-Hil.and O.griffithii Edgew.et Hook.f.Pollen grain sizes of different species and long or short stamen of the same species are various.The form of pollen grains is resembled subsphaeroidal(O.corniculata,O.acetosella),prolate(O.triangularis,O.griffithii) and prolonged prolate(O.corymbosa),with three circular on polar view and three or four colpi on their equatorial view.There are irregular foveolate or course reticulate sexine ornamentations on pollen surface,the meshes are distributed with tuberculate pustute or not.The seeds of O.corniculata are small,seed surface with unequilateral hexagon meshes,and the meshes are full of prismy pustute with uncinate process on its center,while the seeds of O.griffithii are bigger with less course seed surface.