We investigated species relationships in Astraea, a primarily Neotropical genus of tribe Crotoneae centered in Brazil, using data from the nuclear ribosomal ITS, and the plastid trnL-trnF and psbA-trnH spacers. With all species of Astraea sampled, along with representatives from across Crotoneae, the evolutionary history of Astraea was interpreted in a broader framework, as well as divergence time estimates and reconstructions of ancestral areas and morphological character states for Crotoneae. Our results show that Astraea is monophyletic, consisting of three main clades, and that most of its diversification took place from the Oligocene to the Pliocene, coincident with the formation of the South American "dry diagonal". As for Crotoneae, our data show incongruent phylogenetic positions between the nuclear and chloroplast data for most of its genera, and that the ancestor of the tribe was probably arborescent and might have occupied the Amazon Basin, most likely in moist forest, from which it spread throughout South America in the early Eocene. Ancestral state reconstruction recovered deeply lobed leaves and staminate petals bearing moniliform trichomes as putative synapomorphies for Astraea, whereas the absence or strong reduction of pistillate petals is widespread in Crotoneae and may be a synapomorphy for the tribe.

中文翻译：

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Astraea的系统发生学和生物地理学，对Crotoneae（Euphorbiaceae）的进化史提供了新见解。

我们使用核核糖体ITS，质体trnL-trnF和psbA-trnH间隔子的数据，调查了以巴西为中心的热带部族的主要亚热带属Astraea的物种关系。采样了所有的Astraea物种，以及来自整个Crotoneae的代表，在更广泛的框架内解释了Astraea的进化史，以及发散时间估计以及Crotoneae祖先区域和形态特征状态的重建。我们的结果表明，Astraea是单系的，由三个主要进化枝组成，并且其多样化大部分是从渐新世到上新世，与南美“干对角线”的形成相吻合。至于豆科 我们的数据显示，该属大多数属的核和叶绿体数据之间的系统发生位置不一致，并且该部落的祖先可能是树状的，可能已经占领了亚马逊河流域，最有可能在潮湿的森林中，并在整个南美地区扩散。始新世。祖先状态的重建恢复了深裂的叶，并长有带片状毛状体的花瓣，作为阿斯特拉的假定的亚同形，而雌蕊花瓣的缺乏或强烈减少在crotoneae中很普遍，可能是该部落的同形。