Family 'Sapindaceae' or the
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Plants of the Honeysuckle and Adoxa Families. Key Words: Trees with opposite leaves and winged seeds in pairs." |
Most maple trees have simple leaves with palmate venation and 3 - 5 main lobes. A few have compound leaves and others are simple without lobes. A common feature is that the leaves are opposite and the fruit is a schizocarp, often called a samaras or simply helicopters.
Almost everyone recognizes the maple leaf from the Canadian flag, if not from trees themselves. The opposite, usually palmate leaves are a good pattern for recognizing maples. Only the box elder (Acer negundo) has a different type of leaf. Many people will also remember tossing the winged seeds into the air to make "helicopters." If you examine the flowers in springtime, you will find 4 or 5 separate sepals, sometimes colored like petals, and 4 or 5 (sometimes 0) separate petals. The flowers are typically, but not always, unisexual, with male and female blossoms appearing in separate blossoms, often on separate trees. Male flowers have 4 to 10 stamens. In female flowers the ovary is positioned superior and consists of 2 united carpels with partition walls usually present. The ovary matures as two winged seeds, called samaras. Based on genetic evidence, taxonomists reclassified the traditional Maple family as part of the Soapberry family. The genera Dipteronia is native to China. Note that the ash (Fraxinus) of the Olive family has somewhat similar seeds.
APG II submerges both Aceraceae and Hippocastanaceae as synonyms of Sapindaceae. Stevens (APG website) cites an abstract (Li, et al., 2006a) in support of synonymizing Aceraceae within Sapindaceae. This abstract appears to be based on the same data later published by Li et al. (2006b).
Li et al. (2006b) used two chloroplast non-coding regions, psbM-trnD and trnD-trnT. In their analyses, Xanthoceras, traditionally placed in Sapindaceae, was a sister taxon to a clade that included a monophyletic Aceraceae and monophyletic Hippocastanaceae. Thus, according to this preliminary analysis, if Xanthoceras is included in Sapindaceae, Sapindaceae is rendered paraphyletic if either Aceraceae or Hippocastanaceae are recognized. However, this is not the end of the story.
Gadek et al. (1996) used chloroplast rbcL in an analysis that included taxa relevant to Sapindaceae. Based on very limited sampling, they found a monophyletic Aceraceae and a monophyletic Hippocastanaceae. They did not sample Xanthoceras, thus leaving open the question of the paraphyly of Sapindaceae.
Harrington et al. (2005), based on rbcL and matK, found that Xanthoceras was placed within the traditional Sapindaceae. However, the anomalous Chinese endemic Handeliodendron, placed in Sapindaceae by Rehder, was found to be nested within the Hipoocastanaceae clade as a sister taxon to Aesculus. Handeliodendron has deciduous, opposite, palmately compound leaves, as in Aesculus. Based on this, we (the YYPG) continued to recognize Aceraceae and Hippocastanaceae as separate from Sapindaceae, but placed Handeliodendron (which see) in Hippocastanaceae (YYPG, 2006).
Recently in the Flora of China, Handeliodendron was placed in Hippocastanaceae (Nianhe Xia, Nicholas J. Turland & Paul A. Gadek, 2007).
The premature lumping of Aceraceae and Hippocastanaceae into Sapindaceae by APG II is regrettable, an example of basing classification on preliminary unstable phylogenies with poor sampling of taxa. Lumping these taxa accomplishes nothing other than creating confusion when dealing with the MASSIVE taxonomic and ecological literature over the last century in which these families are recognized.
Almost everyone recognizes the maple leaf from the Canadian flag, if not from trees themselves. The opposite, usually palmate leaves are a good pattern for recognizing maples. Only the box elder (Acer negundo) has a different type of leaf. Many people will also remember tossing the winged seeds into the air to make "helicopters." If you examine the flowers in springtime, you will find 4 or 5 separate sepals, sometimes colored like petals, and 4 or 5 (sometimes 0) separate petals. The flowers are typically, but not always, unisexual, with male and female blossoms appearing in separate blossoms, often on separate trees. Male flowers have 4 to 10 stamens. In female flowers the ovary is positioned superior and consists of 2 united carpels with partition walls usually present. The ovary matures as two winged seeds, called samaras. Based on genetic evidence, taxonomists reclassified the traditional Maple family as part of the Soapberry family. The genera Dipteronia is native to China. Note that the ash (Fraxinus) of the Olive family has somewhat similar seeds.
APG II submerges both Aceraceae and Hippocastanaceae as synonyms of Sapindaceae. Stevens (APG website) cites an abstract (Li, et al., 2006a) in support of synonymizing Aceraceae within Sapindaceae. This abstract appears to be based on the same data later published by Li et al. (2006b).
Li et al. (2006b) used two chloroplast non-coding regions, psbM-trnD and trnD-trnT. In their analyses, Xanthoceras, traditionally placed in Sapindaceae, was a sister taxon to a clade that included a monophyletic Aceraceae and monophyletic Hippocastanaceae. Thus, according to this preliminary analysis, if Xanthoceras is included in Sapindaceae, Sapindaceae is rendered paraphyletic if either Aceraceae or Hippocastanaceae are recognized. However, this is not the end of the story.
Gadek et al. (1996) used chloroplast rbcL in an analysis that included taxa relevant to Sapindaceae. Based on very limited sampling, they found a monophyletic Aceraceae and a monophyletic Hippocastanaceae. They did not sample Xanthoceras, thus leaving open the question of the paraphyly of Sapindaceae.
Harrington et al. (2005), based on rbcL and matK, found that Xanthoceras was placed within the traditional Sapindaceae. However, the anomalous Chinese endemic Handeliodendron, placed in Sapindaceae by Rehder, was found to be nested within the Hipoocastanaceae clade as a sister taxon to Aesculus. Handeliodendron has deciduous, opposite, palmately compound leaves, as in Aesculus. Based on this, we (the YYPG) continued to recognize Aceraceae and Hippocastanaceae as separate from Sapindaceae, but placed Handeliodendron (which see) in Hippocastanaceae (YYPG, 2006).
Recently in the Flora of China, Handeliodendron was placed in Hippocastanaceae (Nianhe Xia, Nicholas J. Turland & Paul A. Gadek, 2007).
The premature lumping of Aceraceae and Hippocastanaceae into Sapindaceae by APG II is regrettable, an example of basing classification on preliminary unstable phylogenies with poor sampling of taxa. Lumping these taxa accomplishes nothing other than creating confusion when dealing with the MASSIVE taxonomic and ecological literature over the last century in which these families are recognized.
Genus of the 'Sapindaceae' family:
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Genus species:
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© 2014 Bohemefit for Fuerza International.
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No content or information herein may be used elsewhere on social media, without written permission,
yet alone be out of context and or for content on other social media sites.