Floral development and anatomy of Dirachma socotrana, (Dirachmaceae):: a controversial member of the Rosales
Floral development and anatomy of Dirachma socotrana, (Dirachmaceae):: a controversial member of the Rosales
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DOI：
10.1007/s00606-004-0208-0
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发表时间：
2004-10-01
影响因子：
1.9
通讯作者：
Miller, AG
中科院分区：
文献类型：
--
作者：
De Craene, LPR;Miller, AG
使用 SEM 和 LM 对 Dirachma 的花发育和解剖结构进行了研究，以在形态共性的基础上讨论 Dirachmaae 与假定的姊妹类群（例如鼠李科、锦葵科、Barbeyaceae、Elaeagnaceae）的关系。花在顶生枝的腋生位置开始。由六到八个小苞片组成的副萼围绕着镊状花萼。花瓣的萌生被强烈延迟，原基独立地与雄蕊原基相对地出现。心皮独立出现并在基部弱融合；单个胚珠在轴位发育。托杯通过花瓣和雄蕊之间的原基生长而发育。蜜腺出现在一个袋子中，并被位于花瓣基部的突起上的毛状体覆盖。这表明单生花源自复聚伞状花序。 Dirachma 和鼠李科物种之间的比较表明，它们在花结构和解剖学上具有惊人的相似性。然而，有几个特征是 Dirachma 所特有的，并且支持与 Rhamnaceae 分开的 Dirachmaceae 科。
The floral development and anatomy of Dirachma has been investigated with SEM and LM to discuss the relationship of Dirachmaceae with putative sister taxa (e.g. Rhamnaceae, Malvaceae, Barbeyaceae, Elaeagnaceae) on the basis of morphological synapomorphies. Flowers are initiated in axillary position on terminal branches. An epicalyx consisting of six to eight bracteoles surrounds the valvate calyx. Petal initiation is strongly retarded and primordia arise independently opposite the stamen primordia. The carpels arise independently and become weakly fused at the base; a single ovule develops in an axile position. A hypanthium develops by interprimordial growth between petals and stamens. Nectaries arise in a pouch and are covered with trichomes positioned on a protuberance at the base of the petal. It is suggested that the solitary flowers are derived from compound cymose inflorescences. Comparison between Dirachma and species of Rhamnaceae demonstrates striking similarities in floral structure and anatomy. However, several characters are unique to Dirachma and support a family Dirachmaceae separate from Rhamnaceae.