金丝桃属9种植物种子形态及其系统学讨论

对金丝桃属5组9种植物的种子进行了宏观及微观形态学研究,以探讨岐山金丝桃的系统位置。结果显示,种子形态特征在本实验观察的5个组之间有明显差异。其中金丝桃组种子外形较为细长,种皮纹饰为狭长而规则的矩形网纹;黄海棠组种子稍粗,种皮纹饰为长宽近等的多边形(稀矩形)网纹;元宝草组的元宝草、贯叶连翘组的贯叶连翘以及挺茎遍地金组的云南小连翘种子均较小,元宝草种皮纹饰为负网纹,贯叶连翘种皮纹饰为相邻网纹间有间隙的近圆形网纹,云南小连翘种皮纹饰为复网纹。研究显示,岐山金丝桃的种子形态与黄海棠组最为接近,支持岐山金丝桃归于黄海棠组。

Seed Morphology of Nine Species in the Genus Hypericum L.and Its Systematical Significance

To probe into systematic position of Hypericum elatoides,we studied seed macro-and micro-morphology of 9 species from 5 sections in the genus Hypericum L..The result shows the evident divergence in seed morphology among different sections.Seeds of Sect.Ascyreia are relatively longer and thinner.Testa sculpturings are long rectangular reticula.Seeds of Sect.Roscyna are thicker.Testa sculpturings are polygonal reticula of approximately identical length and width.Seeds of H.sampsonii(Sect.Sampsonii),H.perforatum(Sect.Hypericum) and H.petiolulatum subsp.yunnanense(Sect.Elodeoida) are all smaller in size,but their testa sculpturings are quite different.H.sampsonii has areolate reticula;H.perforatum has circular reticula with spaces in neighbor reticula;H.petiolulatum subsp.yunnanense has double reticula.Seed morphology of H.elatoides is similar to that of Sect.Roscyna.Therefore,evidence from seed morphology suggests that systematic position of H.elatoides is in Sect.Roscyna.