Talk:Cupressus
A genus of c. 16-20 species. Recent genetic evidence (* Little, D. P., Schwarzbach, A. E., Adams, R. P. & Hsieh, Chang-Fu. 2004. The circumscription and phylogenetic relationships of Callitropsis and the newly described genus Xanthocyparis (Cupressaceae). American Journal of Botany 91 (11): 1872–1881. Abstract) shows that the New World Cupressus are less closely related to the Old World Cupressus than previously thought, being more closely related to Callitropsis and Juniperus than to the rest of Cupressus. A change in generic classification for these species is likely in the near future, either to Callitropsis or to a new genus.
Mao et al. (2010) and Terry & Adams. (2015) reversed the circumscription which segregated Hesperocyparis, Callitropsis s.s. and Xanthocyparis s.s. into separate genera. Therefore, the segregation of this genus into Old and New World clades and genera by Little (2006) and Adams et al. (2009) cannot be sustained. The generic circumscription on the taxon page follows Govaerts et al., 2017. Andyboorman (talk) 15:42, 28 February 2017 (UTC)
However, note the recently published Zhu et al. (2018), which has resurrected the proposals to segregate the above genera and revert to a Cupressus s.s. reserved for the Old World species. Govaerts et al., 2018 has decided to follow this circumscription, but with the a number of "Accepted by/Not Accepted by" provisos on their web site. Therefore, it seems that the lumping/splitting debate has not been satisfactorily resolved. Perhaps, WS should maintain a conservative approach for now and retain Cupressus s.l.? See also Christenhusz et al., (2011) Andyboorman (talk) 08:53, 23 October 2018 (UTC)
- Yes; a broad circumscription of Cupressus is the only one that is workable - any subdivision is ver premature with many taxa not yet examined, and the monophyly of Cupressus s.l. still highly likely - MPF (talk) 16:22, 6 January 2020 (UTC)
- You may or may not be right, however, the reversion of Cupressus s.l. to Cupressus s.s is now gaining increasing support. WS must not take a side in this discussion as that would be OR. It would be better to produce pages for the segregates with notes referring to the alternative view. The disputed tag may also be appropriate, as also taking this to the pump. Andyboorman (talk) 18:43, 6 January 2020 (UTC)
- One example of the problems with splitting is that Mu et al. (2006; Front. Biol. China 4: 349−352 DOI 10.1007/s 11515-006-0044-5 ) found a species pair of Cupressus funebris and C. duclouxiana (neither examined by the proponents of splitting the genus) to be sister to C. nootkatensis, with those three in turn sister to C. torulosa: i.e., "Callitropsis" nootkatensis is from their results deeply embedded among Asian Cupressus s.str. The net result is that any splitting of the genus is likely to result in extensive paraphyly somewhere in the group. - MPF (talk) 19:01, 6 January 2020 (UTC)
You make my point for me. I will migrate the discussion to the Pump. But left here for now, but please feel free to remove if appropriate. Andyboorman (talk) 20:38, 6 January 2020 (UTC)
- Pump Discussion was inconclusive but see the recent Mao et al. (2019). BTW Mao et al. (2019) did consider Cupressus funebris and C. duclouxiana in their analysis. Andyboorman (talk) 19:00, 19 February 2020 (UTC)
The taxon page over is only one side of a taxonomic opinion favouring Cupressus s.l. in line with Christenhusz et al. (2011). However, there is a different view shared by Govaerts et al. (2020) and Mao et al. (2019) and quoting the later "This indicates (their evidence) that Cupressus s.l. (Christenhusz et al., 2011; Table 1) is paraphyletic, and can be considered instead as two monophyletic genera, Cupressus (s.s.) and Hesperocyparis, and two monotypic genera, Callitropsis (s.s.) and Xanthocyparis (s.s.)". Information for both views are found in the taxon page Reference Section. Andyboorman (talk) 15:06, 19 October 2020 (UTC)