Cycad id

[tank]

Previous owner didn’t know what species this was.   Handled cold down to 24F with 30% leaf damage, with some leaves completely toasted and some untouched.  I removed all of the old leaves after the new flush.  Grey color is likely from overhead irrigation with well water.  My uneducated guess would be C. circinalis.  Any thoughts?

Edited May 26, 2022 by tank

[Tracy]

1 hour ago, tank said:

My uneducated guess would be C. circinalis.  Any thoughts?

Sounds reasonable to me.  The leaf color throws me a little, but if you see that on other plants from your well water, that is a reasonable explanation.  I find it very difficult to distinguish among the entire rumphii grouping of Cycas.  A few years ago I was over at Jungle Music and they had just got in some large specimens from a plant estate sale that were in large boxes.  I was asking Phil about the id's on a pair of Cycas with a few feet of trunk, and he told me the species but I still couldn't distinguish between the two.  It was my failure, as he seemed to see things I was missing.  Perhaps someone else will be able to assist with some things like the way the leaflets hang off the rachis and nail this one down for you.

[Merlyn]

I put together a sort of ID key for that whole group, because I had a similar unknown Cycas from a local nursery.  Mine ended up as "none of the above" and is probably in the Pectinata group.  But here's a way you can distinguish the various types:

• Circinalis 80-90 degree insertion on rachis w/long tapering tip, raised rib above, and visible but flat below.
• Thouarsii 45-60 degrees with more rounded tip, shiny big grooved midrib top, pale w/ raised rib underside, bluish haze on new flush.
• Rumphii 90 deg leaves glossy green w/flat midrib above, very pale w/raised midrib below.
• Seemannii deep green 45-70 degrees midrib is flat above and raised below.

In the photos it looks like the insertion angle might be close to 90 degrees, so that would mean Circinalis or Rumphii.  Then distinguish them by the raised or flat midrib on the leaflet.  If I had to guess I'd think Rumphii, since the midrib in one of your pictures looks pale green and pretty prominent on the bottom.

[hbernstein]

I would say rumphii because all commercially produced "circinalis" are actually rumphii. Unless the person who planted it was a collector or obtained the plant from an atypical source, it's a rumphii. 

Nice looking plant!

[tank]

Thanks for the info!

To complicate things even more, there is a cycad behind this one that is identified by the old owner as C. rumphii.  It is quite a bit different from the plant in question.  Definitely less cold hardy.  I was warned by the old owner and his gardener that I needed to protect it for the 24F event or it would defoliate.  I ended up wrapping it up in moving blankets and it made it through ok.  I'll post pics of it, possibly in a different thread.

@Merlyn, I'll go out today and check out this plant (and the "rumphii" behind it) to see how this plant matches up with your key.

I will say, the new flush was a really nice pale blue/green and it kept that color for about two weeks.  I think the silvery look on mine is from the mineral deposits from the well water.  I think it will green up a bit when the summer rains kick in and wash the mineral deposits off.

[tank]

Also, the old home owner was a plant collector, so I wouldn't be surprised if he had something unusual.  The yard has been full of cool surprises.

He has/had a bunch of plant nut friends from the university of Florida that would always bring stuff over to try out in his yard.

The house came with about 15+, possibly 20+ various cycads, zamias, encephalartos, dions, ceratozamias, bowenias and a nice stangeria.  He's killed a few macrozamias that I believe died because he had them in shady spots with extremely rich/mucky soil that were overwatered.

[tank]

More leaf photos:

[Merlyn]

Based on the new photos I'd change my opinion.  Seemannii and Thouarsii both have swept forward leaflets, like your bottom photo.  I think that eliminates Circinalis and Rumphii.  The bluish haze and grooved midrib on top, raised midrib below all say Thouarsii, but the pointy tip says Seemannii...maybe.  I don't know how "rounded" they need to be or whether that is really a distinguishing feature.  I'd check out the dimensions here, it's where I collected my "key" from:

http://www.llifle.com/Encyclopedia/PALMS_AND_CYCADS/Family/Cycadaceae/28872/Cycas_seemannii

http://www.llifle.com/Encyclopedia/PALMS_AND_CYCADS/Family/Cycadaceae/28846/Cycas_thouarsii

http://www.llifle.com/Encyclopedia/PALMS_AND_CYCADS/Family/Cycadaceae/31824/Cycas_rumphii

http://www.llifle.com/Encyclopedia/PALMS_AND_CYCADS/Family/Cycadaceae/28817/Cycas_circinalis

[tank]

15 hours ago, Tracy said:

Sounds reasonable to me.  The leaf color throws me a little, but if you see that on other plants from your well water, that is a reasonable explanation.  I find it very difficult to distinguish among the entire rumphii grouping of Cycas.  A few years ago I was over at Jungle Music and they had just got in some large specimens from a plant estate sale that were in large boxes.  I was asking Phil about the id's on a pair of Cycas with a few feet of trunk, and he told me the species but I still couldn't distinguish between the two.  It was my failure, as he seemed to see things I was missing.  Perhaps someone else will be able to assist with some things like the way the leaflets hang off the rachis and nail this one down for you.

Tracy,

Strangely enough, I don't see the "greying" up from the well water on the other plants around it.  I kinda assumed that the blue came from this and maybe from the lighting when I took the pic.  I would say that after looking closely at it today, the leave definitely have a "blueish" tint to them, especially compared to the other possible C. rumphii behind it that I posted in another post.  Both get the same irrigation.

[tank]

17 minutes ago, Merlyn said:

Based on the new photos I'd change my opinion.  Seemannii and Thouarsii both have swept forward leaflets, like your bottom photo.  I think that eliminates Circinalis and Rumphii.  The bluish haze and grooved midrib on top, raised midrib below all say Thouarsii, but the pointy tip says Seemannii...maybe.  I don't know how "rounded" they need to be or whether that is really a distinguishing feature.  I'd check out the dimensions here, it's where I collected my "key" from:

http://www.llifle.com/Encyclopedia/PALMS_AND_CYCADS/Family/Cycadaceae/28872/Cycas_seemannii

http://www.llifle.com/Encyclopedia/PALMS_AND_CYCADS/Family/Cycadaceae/28846/Cycas_thouarsii

http://www.llifle.com/Encyclopedia/PALMS_AND_CYCADS/Family/Cycadaceae/31824/Cycas_rumphii

http://www.llifle.com/Encyclopedia/PALMS_AND_CYCADS/Family/Cycadaceae/28817/Cycas_circinalis

I was starting to think C. thouarsii also, based mainly on looking at online pics of the four plants in the group.  Although internet research is what it is..... 

That said, the new flush was definitely a brilliant blue/green.  I thought I had a pic of it but I can't seem to find it on my phone.

[edbrown_III]

I distriubuted a lot of seeds to the seedbank many years back --- hybrids --- C revolutax taitugensis x dianannensis and  C. revoluta -taitugensis x hainannensis --- even traded a bunch to Chumley  .  so they are floating around ---- they ( C.  hainannenissis have the deep ridges that you portray on underside of leaf   see photo of a pure C.  hainannenisis