Friday, August 19, 2016

Conifer taxonomy

Recently, I tried to find out the exact taxonomy of conifers. I knew that a few years earlier, when I was actively working with it, there were a few issues on Wikipedia concerning the grouping of the main conifer families, namely Araucariaceae, Cephalotaxaceae, Cupressaceae, Pinaceae, Podocarpaceae, Sciadopityaceae, Taxaceae, and actually the grouping of genera in families as well. Guess what changed: not much, not on Wikipedia anyway. The disagreement between Wikipedia pages in different laguages is one thing, but the English pages were contradicting each other pretty heavily. Not even mentioning the position of gymnosperms in the plant hierarchy, which looks even worse. Some examples:

Subclass Cycadidae

  • Order Cycadales
    • Family Cycadaceae: Cycas
    • Family Zamiaceae: Dioon, Bowenia, Macrozamia, Lepidozamia, Encephalartos, Stangeria, Ceratozamia, Microcycas, Zamia.

Subclass Ginkgoidae

Subclass Gnetidae

Subclass Pinidae

  • Order Pinales
    • Family Pinaceae: Cedrus, Pinus, Cathaya, Picea, Pseudotsuga, Larix, Pseudolarix, Tsuga, Nothotsuga, Keteleeria, Abies
  • Order Araucariales
    • Family Araucariaceae: Araucaria, Wollemia, Agathis
    • Family Podocarpaceae: Phyllocladus, Lepidothamnus, Prumnopitys, Sundacarpus, Halocarpus, Parasitaxus, Lagarostrobos, Manoao, Saxegothaea, Microcachrys, Pherosphaera, Acmopyle, Dacrycarpus, Dacrydium, Falcatifolium, Retrophyllum, Nageia, Afrocarpus, Podocarpus
  • Order Cupressales
    • Family Sciadopityaceae: Sciadopitys
    • Family Cupressaceae: Cunninghamia, Taiwania, Athrotaxis, Metasequoia, Sequoia, Sequoiadendron, Cryptomeria, Glyptostrobus, Taxodium, Papuacedrus, Austrocedrus, Libocedrus, Pilgerodendron, Widdringtonia, Diselma, Fitzroya, Callitris (incl. Actinostrobus and Neocallitropsis), Thujopsis, Thuja, Fokienia, Chamaecyparis, Callitropsis, Cupressus, Juniperus, Xanthocyparis, Calocedrus, Tetraclinis, Platycladus, Microbiota
    • Family Taxaceae: Austrotaxus, Pseudotaxus, Taxus, Cephalotaxus, Amentotaxus, Torreya

Subclasses of the division gymnosperms, according to the Wikipedia page of gymnosperms

Ginkgo biloba leaves (source)

In the text above, we see three of the subclasses of gymnosperms contain "traditional" conifers, and three containing related species. A different page, however, talks about a division called Pinophyta, and a class called Pinopsida, where all "traditional" conifers are located. Recapping, the division gymnosperms contain conifers AND some other things like the Gingkgo and cycads. The division Pinophyta, contains ONLY conifers. This could be possible, if Pinophyta was a part of gymnosperms, but they're both divisions, so, as far as I know, they should be on the same taxon level. And the Wikipedia pages do not indicate anything else

Now, my knowledge of taxonomy may not be perfect, but this doesn't seem right. So, I tweeted Ross Mounce, who has been busy with making phylogenetic trees.

To be continued...

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