Cladus: Eukaryota Name Apostasioideae Horan. (1847) ----------- The subfamily Apostasioideae belongs to the orchid family (Orchidaceae). It is a clade, but there is bootstrap support that it is a sister to the other orchid subfamilies. A bootstrap is a method for evaluating the statistical importance of positions of different branches in a phylogenetic tree (= a treelike structure giving the evolutionary development of organisms). The apostasioid orchids are the most primitive orchids, with only two genera. Neuwiedia has 3 fertile, abaxial (= facing away from the stem) anthers, while Apostasia has two fertile abaxial anthers and a filamentous staminode (= a sterile stamen). These primitive features make them, according to some authorities , not true orchids but rather ancestors of modern orchids. However, modern studies (Stern, Cheadle and Thorsch, 1993) point out that the apostasioid orchids are uniquely defined ( = autapomorphous). This makes them unsuitable as models to be the ancestors of the orchids. References * Stern, W. L., V. Cheadle, and J. Thorsch (1993). "Apostasiads, systematic anatomy, and the origins of Orchidaceae". Botanical Journal of the Linnean Society 111: 411–445. doi:10.1111/j.1095-8339.1993.tb01913.x. Source: Wikispecies, Wikipedia: All text is available under the terms of the GNU Free Documentation License |
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