Hydnophytums: Are they Psychotrias?

[Derrick]

As indeed may be all hydnophytinae. I have known about this study for some time but could not previously access a copy.

http://www.bergianska.se/polopoly_fs/1.77677.1329987311!/menu/standard/file/Nepokroeff_et_al_1999.pdf

http://www.amjbot.org/content/early/2014/07/20/ajb.1400076.full.pdf

 

[Aurélien]

These paper purpose to regroup all the genus in the subfamilies of Psychotrieae and Hydnophytineae into the big genus Psychotria?

[Derrick]

The Missouri Botanical Garden website provides an excellent source regarding modern classification.  The following quote indicates that the use of sub-tribe hydnophytinae is now history.

http://www.mobot.org/MOBOT/research/APweb/orders/gentianalesweb.htm

"Myrmecodia, Hydnophytum and related Malesian genera (= Hydnophytinae in the old sense; now = Psychotrieae) are highly modified epiphytic ant plants, and are one of the largest such clades (Chomicki & Renner 2015). The ants live in chambers in the grossly swollen stem (hypocotyl) base, and material brought in by the ants is stored in chambers with a distinctive morphology; nutrients from this material are taken up by the plant. Some species have more or less branched spines arising from the root, stem, inflorescence, and even the torn and eaten surfaces of the leaves (Huxley 1978; Jebb 1991; Huxley & Jebb 1991 for the taxonomy of the group). Close associations with ants have arisen several other times in Rubiaceae. Thus there are several myrmecophytic Naucleeae, the ants living in hollowed stems in plants with a much more "normal" appearance than that of many Hydnophytinae; interestingly, some of these myrmecophytic clades have diversified notably slowly and/or have very limited distributions (Razafimandibison et al. 2005). All these clades are likly to be less than 19 m.y.o. (Chomicki & Renner 2015)." http://onlinelibrary.wiley.com/doi/10.1111/nph.13271/pdf