中国蓼属(蓼科)三新种

Three new species in the genus Polygonum (Polygonaceae) from China

描述了中国新疆蓼科Polygonaceae蓼属萹蓄组PolygonumsectionPolygonum3新种。乌鲁木齐萹蓄P.urumqienseF.Z.Li,Y.T.Hou&F.J.Lu在体态上与萹蓄P.aviculareL.很相近,但花在枝上部叶腋簇生成穗状花序,雄蕊5–6枚,瘦果两型,长果表面密具不规则排列的小点,易于区别。塔城萹蓄P.tachengenseF.Z.Li,Y.T.Hou&F.J.Lu在枝上部的花不形成总状花序,雄蕊8枚,瘦果表面具成行的小点等方面与萹蓄近缘,其区别在于3–6花仅簇生于枝上部叶腋,叶片条状披针形,背面主、侧脉极其隆起,托叶鞘较长,约达1.1cm,具15–20条纵脉;又因其茎直立,花簇生于枝上部叶腋而与展枝萹蓄P.patulumM.Bieb.相近,其区别在于叶背面中脉和侧脉极其隆起,托叶鞘较长,达1.1cm,具15–20条纵脉,枝上部的叶不渐小,花在枝上部叶腋簇生,不形成总状花序,瘦果表面具成行的小点。石河子萹蓄PolygonumshihezienseF.Z.Li,Y.T.Hou&F.J.Lu茎直立,花3–6朵簇生于枝上部叶腋,雄蕊8枚,瘦果表面光滑,略具光泽,与帚萹蓄P.argyrocoleonSteud.exKunze相近,区别在于叶背面中脉和侧脉极其隆起,托叶鞘长,达1.1cm,具15–20条纵脉,花在枝上部叶腋簇生,不形成总状花序;同时在体态上又与塔城萹蓄十分相近,但其枝上部的叶逐渐变小,瘦果表面光滑,略具光泽,易于区别。对3个新种及其近缘种的花粉形态、叶表皮特征和瘦果微形态进行了光镜和扫描电镜比较观察。

Three new species in Polygonum sand illustrated. Polygonum urumqiense F. Z. Li, Yection Polygonum （Polygonaceae） from Xinjiang, China, are described . T. Hou ＆ F. J. Lu is similar to P. aviculare L. in habit, but differs by having flowers densely clustered and spicate in the upper part of branches, stamens 5-6, and two types of achenes （the longer one densely and irregularly granulate on surface）. Polygonum tachengense F. Z. Li, Y. T. Hou ＆ E J. Lu is similar to P. aviculare in the flowers not forming a raceme in the upper part of branches, the stamens 8, and the achenes striate-granulate on surface, but differs by the leaf blades linear-lanceolate, the midvein and lateral veins conspicuously raising abaxially, the ochreae longer, up to 1.1 cm, 15-20-veined, the flowers 3-6 clustered together in the upper axils of branches. This species is also similar to P. patulum M. Bieb. in the erect stem, and the flowers 3-6 clustered together in the axils of the upper part of branches, but differs by the midvein and lateral veins of leaves conspicuously raising abaxially, the ochreae longer, up to 1.1 cm, 15-20-veined, the leaves in the upper part of branches not becoming smaller gradually, and the flowers clustered in the upper axils of branches not forming a raceme, and the achenes striate-granulate on surface. Polygonum shiheziense E Z. Li, Y. T. Hou ＆ E J. Lu is similar to P. argyrocoleon Steud. ex Kunze in the erect stem, the 3-6 flowers clustered in the upper axils of branches, the stamens 8, and the slightly smooth achenes, but differs by the midvein and lateral veins of leaves conspicuously raising abaxially, the ochreae longer, up to 1.1 cm, 15-20-veined, and the flowers clustered in the upper axils of branches not forming a raceme. This species is also similar to P. tachengense in habit, but differs in the leaves borne in the upper part of branches becoming smaller gradually and the smooth, slightly shiny achenes. The pollen morphology, leaf epidermal characters and achene micromorphology of the three new species and their relatives were comparatively observed under the scanning electron microscope （SEM）.