紫荆族的脉序研究

LEAF VENATION OF CERCIDEAE(LEGUMINOSAE)

摘要:

本文对代表豆科云实亚科紫荆族全部五个属．即紫荆属、腺叶紫荆属、格里芬豆属、拟羊蹄甲属和羊蹄甲属的几乎全部系或亚组的１３４个种或种下分类单元的叶脉序进行了研究，并描述了本族２０个基本脉序类型．在紫荆族中，腺叶紫荆属和拟羊蹄甲属的脉序式样非常相似；紫荆属的种类的脉式样以全绿叶，一级脉不及绿等特征组合有别于本族其它属；格里芬豆属的脉序高度特化，有别于紫荆亚族的所有类群；羊蹄甲属是叶脉序式样最多样化的类群．在羊蹄甲属中，羊蹄甲亚属和显托亚属的脉序式样非常多样化．Ｅｌａｙｕｎａ亚属的两个组和Ｂａｒｋｌｙａ亚属的脉序式样非常相似．Ｂａｒｋｌｙａ亚属的仅有种了香叶羊蹄甲的脉序仅以其叶全缘区别于Ｅｌａｙｕｎａ亚属．脉序性状支持把Ｃａｎｓｅｎｉａ系、白花羊蹄甲系、羊蹄甲系、绿花羊蹄甲亚组、总状花羊蹄甲亚组、Ｅｌａｙｕｎａ亚属、伞房系、Ｃｈｌｏｒｏｘａｎｔｈａｅ系、棒花系、掌叶组和萼管组等作为自然类群的观点．在本族植物的脉序类型中，一级脉及缘、全缘叶、发育完好的脉岛等性状常相关出现；另一方面，一级脉不及缘，具二小叶或叶深裂，脉岛发育不完善及盲脉多分枝等性状常相关出现．如同形态和花粉性状，脉序性状能为紫荆族的分类提供另一方面的佐证，但只有当与其它方面性状一同使用时，才能得到较可靠的结论．

Abstract:

Leaves of 134 species or infraspecific taxa,representing almost all series or subsections of thefive genera of the tribe Cercideae:Cercis,Adenolobus,Griffonea,Brenierea and Bauhinia,have beenstudied.Twenty venation types have been described.In the tribe,Adenolobus and Brenierea have very similar venation patterns.Cercis species alsohave their own characteristics.Venation of Griffonea leaf is very specialized and characteristic,while Bauhinia is very diverse in venation patterns.In the genus Bauhinia, both subgenera Bauhinia and Phanera are very diverse in aspects of leaf venation, while venation types of the two sections of Subgen. Elayuna are very similar.Theleaf venation of B.syringifolia, the only species of Subgen. Barklya, is one of the best developedvenation types and is very similar to that of Subgen. Elayuna type.The venation characters support the distinction,if not necessary being monophylies,if Ser.Cansenia,Ser.Acuminatae,Ser.Purpureae,Subsect.Viridescentes,Subsect. Tacemosae,Subgen.Elayuna,Ser.Corymbosae,Ser.Chloroxantheae,Ser.Clavatae,Sect.Palmatifolia,and Sect.Tubicalys.Like other morphological or palynological characters,leaf venational characters can be a source of inrormation for systeratics,but it can only be used in systematics together with datafrom other aspects.