Derek the Hybrid Detective

DD0114 Puya berteroniana (Bertero 115)
by Derek Butcher January 2014

This is one of the big Puyas and is not for the ‘normal’ backyard but can be found in Botanic Gardens with the Adelaide Botanic gardens being one example.
(Ed. The BSA held a special BBQ day in November to view the P. berteroniana at Mt Tomah Botanic Gardens, west of Sydney.)
You see, when it flowers it can get to 4.5 metres high so is an impressive sight when in flower. Each flower is a metallic blue-green colour. A plant that looks like this but only 2.5 metres high when it flowers is Puya alpestris. Both have an odd habit of having the top part of each flowering branch naked of flowers and looking like nature has provided the birds with somewhere to perch. The botanists call Puyas with this habit as subgenus Puya and they are generally on the large size. The other subgenus is Puyopsis where the flowering branch has flowers all the way to the top.

This is where the problem starts. In 1896 Mez decided to describe parts of a plant that had been found near Valparaiso in Chile by Carlos Bertero. Let us remember the transport situation at that time and ponder on the thoughts of such a collector. “How am I going to get this thing out of the wild – I’ll just collect as much material as I am able!” Mez decided it had a totally fertile inflorescence and described Puya berteroniana which was subsequently placed under subgenus Pitcairniopsis which eventually became subgenus Puyopsis. As a side issue, current molecular studies are showing that the old notion that Pitcairnia and Puya are closely related is in error. Back to the plot. In 1935 in Das Pflanzenreich, Mez still had Puya berteroniana under Pitcairniopsis. In the same year Lyman Smith entered the arena and he was convinced an error had been made possibly because all the plants being found in the wild near Valparaiso that could be linked to P. berteroniana had an inflorescence that had cocky perches! Surely Mez had made a mistake.

So, up to 2013 we had P. berteroniana for the large plant found around Valparaiso and the more southerly smaller plant known as P. alpestris.
Was Bertero 115 a one off – a natural hybrid or mutation? Had Lyman Smith and all the subsequent writers made wrong assumptions? Georg Zizka and his co-workers thought so and we see details published in Brittonia 65(4): 387-407. 2013.
So, now we have P. berteroniana treated as P. x berteroniana and NOT in cultivation and a new P. alpestris subsp. zoellneri to take its place.
Just think, the next time you are in a Botanical Garden and you see a plant with Puya berteroniana on the label you can flash a copy of this article to put them on the right path!

Finally a few words on natural hybrids. In Brittonia 65(4): 387-407. 2013. We find:
‘However, Puya berteroniana Mez is here regarded to be a very rare taxon of hybrid origin. Up to now, Puya hybrids have been only reported by Luther (2010) who listed two species of hybrid origin (P. x loxensis Manzanares & W. Till, P. x pichinchae Mez & Sodiro), but no hybrids between representatives of different subgenera have been recorded up to now. However, a hybrid between the genera Puya and Deuterocohnia, x Pucohnia G.H. Anderson ex D.A. Beadle, was published by Beadle (1991).’
Natural hybrids are generally on the backburner as far as botanists are concerned and many are referred to just by parental formula, and the only place they are listed is Just search on nat hyb to get a list. It is also possible if only one plant is found that the difference can be explained by mutation but we still treat it a natural hybrid with putative parents. It should be noted here that the parental species names are in alphabetical order to easily check on double entries because in natural hybrids nobody knows for sure which is the seed parent. There are also many natural hybrids that have been declared but nobody has bothered to publish the name with a multiplication sign.

The citation ‘Beadle (1991)’ may be referrable by the academic botanist who has easy access to University libraries but mention could have been made to the Bromeliad Cultivar Register where easy access to this information is available.

P. berteroniana
Mt Tomah Botanic Gardens, NSW
Ian Hook 11/11.
P. alpestris
Chris Larson 11/06.

Updated 24/01/14