How many pairs of leaves should Argyroderma congregatum have?

[MatDz]

Some time ago I have acquired a pair of Argyroderma congregatum plants (HH5032 and a "no-id"), and am now wondering how many pairs of leaves I should keep on them?

Description in "Illustrated Handbook of Succulent Plants Aizoaceae (2nd Ed, A-Z), Heidrun E.K. Hartmann (2017)" reads:

L hood-shaped, spreading, the pair 15–30 mm l, 10–20 mm b, yellow and persisting with age;

And the key to the species, ibidem, goes as follows:

• 1. Old leaves yellowish and persistent or grey and deciduous; -> 5
• 5. Yellow old leaves persisting over several years; -> 6
• 6. Foliage leaves hood-shaped; -> A. congregatum

Both of which tell me that there should be more than one pair at a time, but I couldn't find any reliable answer or photograph to support this. Even https://www.inaturalist.org/taxa/119882 ... wse_photos shows plants with 1-2 pairs at a time, which I think should have more if the old leaves are persistent "over several years", am I right? Maybe just one of the photos has these "yellow old leaves persisting over several years", but still it's just one extra pair.

Edit: To clarify, by "keep on them" I mean watering more or less so that the old pair either shrivels or stays, similar to how I "control" my Lapidaria margaretae.

Edit edit: A curiosity about L. margaretae I just read "In wetter and darker cultivation, up to 12 leaf-pairs can persist as foliage leaves on the plant, i.e. they live longer than only one season, in contrast to the situation in habitat. In this way, the plant develops into a column, flowering terminally, the stem being continued by one of the originally lateral side branches."

[rthr]

1 or 2 leafpairs is normal, depending on the time of year. Once the new leafpair emerges, the old pair should begin to wrinkle and slowly dry up, gradually turning yellow and then grey before eventually crumbling or flaking away. So Hartmann is referring to the old dried leaves when she mentions them persisting - sometimes the highly succulent leaves can take several years to fully decay and meanwhile the stacked remains of old dried-up leaves can often be seen hugging the base of the new bodies.

Re Lapidaria, I'd be concerned if mine regularly had more than 3 or 4 leafpairs. But then I like my mesembs to look natural. 12 leafpairs may be possible but it's not usually desirable. Like Argyroderma, they much prefer bright over dark conditions.

Catherine

[MatDz]

That all makes sense, thank you! The description wasn't 100% clear to me, but that's probably because of not so great experience in reading them.

On the Lapidaria, it's absolutely a curiosity I would love to see in person, but not necessarily do this to my own plants!