Dioscorea Elephantipes

[eduart]

Well, I keep them outdoors...

It's a bit risky (I lost one some 15 years ago) But they do well in Auckland, New Zealand.

[Tina]

Cor thats a lovely knobbly one

[Pattock]

There are some pictures of very knobbly Mexican relatives in this piece on the Annals of Botany site which goes into some of the history of their involvement with the development of the Pill and corticosteroids. Huge amounts harvested from the wild for turning into steroids.

https://www.botany.one/2021/03/how-a-fo ... for-women/

Our native yam Dioscorea communis (née Tamus communis, the black bryony) is said to produce a tuber up to 60cm across but I can't find pictures of any that size. Does anybody have them in their garden? I don't remember seeing any in Manchester, though they do grow here. I saw a lot in Lincolnshire and Berkshire.

[iann]

Mine, not D. elephantipes, are just starting on their summer growth.

[HaoBao]

Thanks for the link Pattock, and the advice from others, looking at other people’s pictures mine has got a lot of catching up to do!

[esp]

I grow all my seed raised plants, young and old, of this species in an unheated hampshire greenhouse, with recorded temperatures down to minus 6, without any damage in over 15 years either to leaves or caudex.

Very interesting, David. So do you tend to grow it mostly as an autumn/spring grower, hold off on the water during cold spells in winter?
Sounds like a spare seedling or two may be kept out in the cold this winter!

[Tina]

Ian,
So what's the difference with these d. strydomiana then, they look like d.elephantipes but with more pronounced bumps ( one of mine is like this).
Will they hybridise ? I saw they are endangered, do you get seed yet ?.

[iann]

Ian,
So what's the difference with these d. strydomiana then, they look like d.elephantipes but with more pronounced bumps ( one of mine is like this).
Will they hybridise ? I saw they are endangered, do you get seed yet ?.

D. strydomiana is described as "shrubby" with a large (up to a metre) caudex although the caudex is somewhat more irregular-shaped than D. elephantipes. It is a summer grower. My plant is not exactly shrubby, the stems produced each year die back completely and it starts again the next year. My growing conditions may not be ideal, but it does seem dead set on winter dormancy. It is certainly different from D. elephantipes but in some ways seems intermediate between the two, or at least how I expect D. strydomiana to be. The stems are self-supporting to a point, but arch over at a couple of feet tall, and the leaves are less heart-shaped.

I still haven't got flowers. I have seven plants eating me out of house and home, but I don't know which sex each one is.

[Pattock]

I still haven't got flowers. I have seven plants eating me out of house and home, but I don't know which sex each one is.

If they were mine I would guess three possibilities.

1) Age. Are they 16 years old yet (anthropomorphic joke)?

2) Light. Dioscorea strydomiana is found in the open, unshaded. I have a lot of experience growing unsuitable plants on windowsills. I once had a "house"plant that crawled along the table for a metre before getting to the window and growing up straight and unsupported. A reflective curtain behind (or angled above) can increase the lighting enough to make some plants happy. Perhaps that would be enough to keep the stems upright and to ripen the stem enough to flower. From the Kew Herbarium specimens the leaves are not heart-shaped, though the fruit are.

3) Light. Your window appears to be facing a street. Street lighting at night messes up everyone's biorhythms.

[iann]

I've tried them in a greenhouse and not much changed except the leaves got scorched. They also don't grow so well when nights are cool which restricted the growing season. Not ideal, I don't have a tropical greenhouse, so I just do the best I can. They're over 10 years old now, so maybe they'll start to grow up and do adult things soon.