PUSHING THE BORDERS

Paul S wrote: ↑Sun Dec 01, 2024 1:47 pm Totally different. What are they?

Cordyline australis is geogrraphically variable over New Zealand, and Philip Simpson suggests introgression from other species across the range may explain that.

I hesitate to suggest this reference, but Wikipedia has a section on 'regional diversity' informed by Simpson's work.

Chad

edit. The link to Amazon for Philip Simpson's book doesn't seem to work anymore, but the Amazon page is still there. Search for 'Dancing Leaves: The story of New Zealand's cabbage tree, ti kouka' in Amazon, or elswhere, for details of his book.

An interesting overview - thanks for that!

Thank you for the comments and thoughts on this subject, it remains a bit of a puzzle, but we could perhaps conclude that some C.australis have died but perhaps they were a certain strain that's less adapted to extremes and prone to pathogens?

The Mediterranean stone pine which grew at Kew for over 100 years, before being killed by the 2022 heatwave, is a good example. Climate change, no matter how slight, will have a negative effect on plants which have grown acclimatised to our maritime climate, with an even more temperate climate further west.

I'll try a few of the forms of Cordyline australis with a bit more confidence.

Paul, I think there's a great degree of variation in C.australis which has mostly gone unnoticed (by me anyway) because the differences are very subtle. I think there are also some supposed C.australis with mauve flowers and blue/purple berries. I've also seen a few specimens with extremely narrow leaves.

Cordyline 'Peko' is the fastest cultivar, getting to a few metres in height within 5-6 years in the South East of England.

Also meant to add, Charlie I agree with you. A huge trunk with a little sprig of leaves at the top is not particularly attractive. I think Cordylines look best planted in groups of varying heights.

The dwarf 'Karo Kiri' retained leaves all the way down their stems in my old garden. With short leaves, they almost gave the appearance of giant Araucaria saplings!

RobSta wrote: ↑Tue Dec 03, 2024 8:37 pm I think there are also some supposed C.australis with mauve flowers and blue/purple berries. I've also seen a few specimens with extremely narrow leaves.

Not supposed - I had one here in the row of Cordys I had along the side of the front garden (all gone now). It was never strong grower and had particularly thin leaves.

More widely, though - I get that C.a is variable and the explanation in that link os interesting. But still I wonder why, all of a sudden, this upright flowered form has become the norm here. I wonder what the source is - there is no one major player on the wholesale market in this area so they would have most likely been sourced from a variety of nurseries.

We had a short discussion on Cordylines many years ago, several of the contributors are now sadly no longer with us but its interesting to note it reflects a lot of what has bee said here (although no mention of disease or fungus)

https://www.pushingtheborders.com/phpBB ... yline#p857