摘要
斜翼属（Ｐｌａｇｉｏｐｔｅｒｏｎ）具有奇异的性状组合，与该属有关的类群有３个亚纲１０个目的１７个科。斜翼具曲行羽状脉，较高级脉发育至四级脉，网眼发育不完善，盲脉２－３次分枝：气孔器近环列型或无规则型，限于下表皮；异面叶，中脉维管束由３束组成，主要两束的韧皮部相向排列，二者旁边有一附属维管束；叶柄维管束圆形，具胶丝。木材管孔唯一，散生，径向直径５２．５－９７．５μｍ，导管分子长２３４－９１８μｍ，具单穿孔板，异管具具缘纹孔，互列，导管内无内含物及侵填体；纤维管胞；轴向薄壁组织极稀，傍管型；单列射线多，多列射线２－６细胞宽，异型。综合的解剖学特征支持斜翼科的建立，但该科与所有相关类群均有十分明显的差异，仅与卫矛科、牛儿苗目、和大戟科比较相似。
Plagiopteron is a monotypic genus and its affinities have not been ascertained for a longtime, but 17 families of 10 orders in three subclasses have been referred to this genus.P.suaveolensGriffith is the only representative of this genus and very rare in natural population and quantity.Here presented is the anatomy of leaf and secondary xylem,including leaf architecture.Thevenation is eucamptodromous pinnate. Only quaternary veins of higher orders veins are well de-veloped with the weak development of the quinarv veins.The veinlets branch two or three times.Areolas are imperfect.Stoma is confined to the abaxial surface of leaves and the stomatal complexis intermediate cyclocytic and anomocytic types Indumentum is dense and stellate on branchs andthe abaxial surface of leaves.Leaves are dorsiventral. The midrib consists of three vascular hun-dles,of which the phoems of the two main ones are arranged face to face,and the third one is be-side these two ones.The petiolar vascular bundle is completely circular.Pores of secondary xylesare solitary,52.5-97.5μm in tangential diameter.The vessel elements are 234-918 μm in length,Perforation is simple pitting of the vessels is bordered and alternate. Pits to parenchyma and tofibres are semibordered.Fibre elements are fibre-tracheid. Axial parenchyma are very scanty andparatracheal.Uniseriate rays are numerous.The multiseriate rays are 2-6 cells wide and of heterogenous Kribs IIb.The genus Plagiopteron is compared with alI the 17 families refer- red earlier as affinities of the genus.The comprehensive anatomical features support the estab- lishment of the monotypic family Plagiopteraceae.Anotomically the family is considerably dif- ferent fromevery family suggested as affini ties earlier, but relateively related to Celastraceae,Geraniales and Euphorbiaceae.
出处
《云南植物研究》
CSCD
1995年第4期439-444,共6页
Acta Botanica Yunnanica
基金
国家自然科学基金
关键词
斜翼属
解剖
系统学
叶
茎
Plagiopteron,Anatomy,Systematic significance
