我国三种苦草的比较形态观察

苦草属(Vallisneria)在我国分布广,蕴藏量大,目前已发表的种类有苦草(V.spiralis L.)密齿苦草(V.denseserrulata(Makino)Makino)刺苦草(V.spinulosa Yan),亚洲苦草(V.asiatica Miki),大苦草(V.gigantea Gtaco.)(产台湾),但对这5种植物仅在宏观的形态特征方面作一般描述,微观方面的资料尚感欠缺。本文特对密齿苦草、刺苦草和亚洲苦草作较详细论述。为了核实野外所采标术雌雄株配对是否正确和进一步深入研究,我们对每种苦草只用同一果实的种子在室内进行播种培植,以观察比较它们之间各个发育阶段的形态特征。此外,还利用扫描电子显微镜对其雄花、花粉粒和种子进行了观察研究。结果表明:亚洲苦草的雄花仅有1枚发育雄蕊;花中无退化雄蕊和退化花瓣;果实长园柱形,光滑无刺;种子倒卵状长棒形。种皮上有许多腺毛,而密齿苦草和刺苦草的雄花均具2枚发育雄蕊,花中各有1枚退化雄蕊和退化花瓣。但前者的果实是三棱状长柱形,光滑无刺;种子倒卵状长棒形,无毛状或翅状突起物。而后者的果实虽仍为长柱状三棱形,但各条棱上有小刺状突起;种子倒卵形,有5—2翅。

COMPARATIVE MORPHOLOGICAL STUDIES ON THREE SPECIES OF VALLISNERIA FROM CHINA

The present investigation has been carried out in order to study the morphological characters of V. denseserrulata ( Makino ) Makino, V.spinulosa Yan and V. asiatica Miki. comparative studies of macroscopy and ultrastructures ( by electron microscope(have been made between the wild and indoor cultivated plants. The results obtained reveal that their morphological differences are as follows: Male flowers of V.asiatica, staman 1 , without rudimenuary petal and stamino-de; fruit columnar, smooth; seed club-shaped, with many glandular hairs. Male flowers of V. denseserrulata and V. spinulosa, stamens 2 , rudimentary petal 1 , staminode 1 ,fruit columnar triquetrous. But fruit of V. denseserrulata is smooth, seed club-shaped without glandular hairs and wing, while fruit of V. spinulosa quetrous spinulate, seed obovate, wings 5- 2.