True Sabal Causarium Identification?

[DallasPalms]

I couldn't be more confused about Sabals, Causarium specifically. I have come across several trees in town with varying features. Is there someone who KNOWS the real stats. On one of the palm society pages the seed size measure is left with a ? I've read that causarium seeds point up? Or maybe it was Mexicana. I found one tree with barely a trunk and seeds as small as a Palmetto which I think are the trees easily defined by their showy criss cross trunks? with smaller leaves that are similar to causarium but smaller... yes, no?

I read that Causariums have gray trunks... darker green much larger leaves? Most of the photos on google show a regular tree with a regular sized crown... Texanas/Mexicanas seem to be the giants with much larger crowns and larger seeds as well, but I read somwhere that Causariums are the giants of the Sabal family. Every Sabal I've seen but one has the same trunk in terms of color though i found one with a much thicker trunk.

Until Yesterday - I was looking closer and I came across the tree In the photo. It has a much more gray looking trunk but perhaps it just weathered differently. I also see a regular palmetto but with wood colored boots. I found another one with what I call a Palmetto trunk with palmetto leaves that have a little more bend in the leaf @ double bend giving it a slightly more exotic look.

 

What makes a Causarium leaf different is it more like a Puerto Rican hat shape than others? I also read that Causarioum has a close relative with the extra bend in the leaf. I do realize these cross readily I just want to know if I found a true causarium with fairly large leaves and medium sized seeds. 

It seems to me that the weight of the seeds is what makes them fall... I only found one tree growing in shade with larger dark green leaves (yellowing is darker than standard trees too) and smaller seeds 7-10mm. Every other tree other than what I believe to be Palmetto has larger seeds and Palmetto has the smaller not so huge leaves that grow more densely with shade. I found one with in between sized fruits half the size of Mexicana seeds and larger leaves than a Palmetto. True Causarioum or potentially a hybrid?

Please share what you know or any threads or links with good information that I can read 

 

Edited December 4, 2020 by DallasPalms

[mnorell]

I'm sure that palm is not S. causiarum. Sabal causiarum is a massive palm, like a Bismarckia or a big Royal, with a very thick trunk. I would assume due to your location in Dallas, what you have there is either S. palmetto or S. mexicana, which are much more common there. Leaves of S. causiarum are gigantic compared to those of S. palmetto. I grew a number of Sabal species in my garden in Natchez, Mississippi, and raised from infancy to nearly 30' in height, two large S. causiarum, as well as many other species, and the fact is, when you have an S. causiarum, you're likely to know it!

But looking at an overall photo of the plant is at best a superficial image, until you examine the details of the plant itself. The easiest way to make sure is to look for the long, papery ligules, which are large and distinctive on S. causiarum. also, if you have fruit to examine, Scott Zona writes that S. causiarum and S. domingensis share a unique trait, fruit being longer than wide. See his monograph on Sabal (see here for a downloadable pdf on ResearchGate) and you might be able to figure out what you have there. Weirdly, Scott Zona omitted those prominent ligules in his monograph, but O.F. Cook noted them in his original description of the plant, in Synopsis of the Palms of Puerto Rico (as Inodes causiarum). See here. Diagnostic traits are also described on Palmpedia in the page for Sabal causiarum.

[sonoranfans]

https://scholarship.claremont.edu/cgi/viewcontent.cgi?article=1462&context=aliso

Causiarum: "Fruit spherical or occasionally oblate-pyriform, black, 7.1-10.8 mm in diameter, 7.5-10.4 mm high; seed oblate concave, 5.9-7.8 mm in diameter, 4.3-5. 7 mm high; embryo supraequatorial, rarely equatorial or subequatorial."  (My causiarum has ~ spherical fruit)

Domingensis: "This species has long been confused with S. causiarum, a species found on Puerto Rico and the southern coast of the Dominican Republic. The species are readily distinguished on the basis of fruit size: 11.5-14.1 (12.7 ± 0.7) mm in diameter and 11.0-14.4 (13.1 ± 1.0) mm high for S. domingensis versus 7.1- 10.8 (9.8 ± 0.5) mm in diameter and 7.5-10.4 (9.4 ± 0.7) mm high for S. causiarum."

 

If you read the monograph you will find that Zona described likely incorrect identification of causiarum by many perhaps due to the examination of single examples of sabals and their "morphological plasticity" as he states.  This means that palms from different areas had variable morphological consistency and Zona sampled a number of palms not just one.  He describes fruit size as the differentiator between sabal causiarum and its closest relative in the sabal "cladeogram", sabal domingensis.  This monograph makes use of microscope leaf crossection slides and flavinoid chemistry panels as well as morphological measurements from different areas, its extensive in information content so more likely to identify the palms.  This is obviously not easy and not something that others have done on sabals.  This is why I believe this monograph is definitive and the morphological plasticity may explain the omission of ligules which are very obvious (so if definitive, why were they missed with such a detailed study),  Ligules may or may not be expressed in other sabals like domingensis and maritima the closest relatives in some climates.  My causiarum was sold to be as domingensis ten years ago and the royal palm society was still erring in identification in 2005 so it a non trivial identification.

I would also say as Mike said those palms are likely not causiarum due to trunk thickness being about 60% of the expected thickness.  They are probably sabal mexicana.

 

 

[PalmatierMeg]

For me other than sheer size (huge) I find the abundant, distinctive ligules of S. causiarum this palm's distinctive feature. They papery, 4-6" wide and look like strips of calculator receipts.

[OC2Texaspalmlvr]

@PalmatierMeg My fav sabal hands down always a pleasure seeing a pic of yours =) 

[mnorell]

My two specimens came from the now-defunct YuccaDo Nursery in southern Texas, and grew from 1' seedlings to 25-30' (the largest of the two) in about 15 years on the SE side of the house. I'm sure this made the leaves stretch and enlarge somewhat, but wow, they are huge and beautiful. I think the bootjacks are just now starting to pop off at ground level, and probably the crown will shrink a bit now that it's getting above the roof and into a more full-sun position. And they have those distinctive, floppy ligules. I'm still so impressed that an imposing palm like this, from such a tropical homeland, can be so cold hardy. It sailed through 2010 (three solid days below freezing, to a low of 18F) and took some cosmetic damage in the 13F freeze in 2018, but quickly grew out of it. It's always a pleasure for me, when visiting the old house in Natchez, to enjoy the garden and in particular those S. causiarum. I'm shocked this is not a landscaping standard throughout the 9a Gulf South. It would fill the "Bismarckia gap" for about 100 miles of real estate in from the Gulf.

[96720]

When do they start showing the ligules I have some that are just starting to trunk and am trying to figure out if they are causiarum

[mnorell]

What's the overall height of your plant...when you say "starting to trunk" do you mean bootjacks are peeling off and trunk is starting to show, or just that you are thinking the entire crown is about out of the ground, so to speak...if it is that big, you should be seeing the ligules by now. But as Tom mentioned above, and as I saw referenced in another source, the ligules may only occur in the Puerto Rico population, while in the Hispaniolan group the ligules may not be present at all. Do you remember where you sourced your plants?

[Kris]

10 hours ago, PalmatierMeg said:

For me other than sheer size (huge) I find the abundant, distinctive ligules of S. causiarum this palm's distinctive feature. They papery, 4-6" wide and look like strips of calculator receipts.

Beautiful palm.

 

Love,

Kris.

[96720]

I got them from jungle music 

[sonoranfans]

14 hours ago, 96720 said:

When do they start showing the ligules I have some that are just starting to trunk and am trying to figure out if they are causiarum

my palm did not show ligules until the trunk started swelling and then they gradually came in.  Not many show domingensis here, cant recall more than 1-2 palm talkers with them.  We have seen ligules on causiarum with the small fruits but we havent seen lots of domingensis without ligules.  Domingensis in habitat show some huge smooth trunks(3' thick) too so that is not differentiating from causiarum.  According to Zona both have inflorescences as long as or longer than the leaves.  Causiarum in habitat tend to brown leaves starting at the horizontal, not so for domingensis which seems to hang on longer.  I had a "sabal blackburniana" in arizona that showed 8-12" ligules, but it was no causiarum, too small, and it was in the desert an extreme climate.  The ligules on my causiarum are about half the size of those on megs palm and my palm is a bigger palm with 8-9' trunk.  In order for causiarum to be definitive for ligules, and it may be, ALL domingensis must not have them as those palms are very similar.   Same is true for the fruits, ALL domingensis must have the larger fruits or fruits will not be differentiating features.  Observations on our causiarum palms are nice but not definitive by themselves.  You would need to show that no other similarly sized sabals have the ligules for those to be definitive.  So due to variations in sabal morphology and the fact that many arent growing them in habitat, it leaves the door open for morphological plasticity(change) due in part to horticultural conditions to make palms within a species to show differing morphologies.   Here is my palm as of this morning, same photo but closeup for viewing ligules which are no so big.  My palms leafbases come off by pulling the last 2-3 years.  I measured the trunk thickness at about 40"  at the maximum bulge in the base and the crown is 25'+ across maximum leaf tip to leaf tip.  why the smaller ligules and why the non persistent leaf bases?  Morphological plasticity?  The fruits are 9-10mm spherical, not pyroform.

[sonoranfans]

Here are some sabal causiarum seedlings.  They are about 18 months from seed(?).

[Fallen Munk]

1 hour ago, sonoranfans said:

Here are some sabal causiarum seedlings.  They are about 18 months from seed(?).

Look great!  You selling?

[sonoranfans]

1 hour ago, Fallen Munk said:

Look great!  You selling?

Sorry, these seedlings are not for sale.  I sent you a PM.

[sonoranfans]

sabal domingensis grown in monaco for comparson, its about the same size.  That is a fat trunk! 

[Fallen Munk]

16 minutes ago, sonoranfans said:

sabal domingensis grown in monaco for comparson, its about the same size.  That is a fat trunk! 

Wow, that's a monster!

[DallasPalms]

This information is really helpful Thanks everyone. So I'm wondering since Sabal Palmetto trees also have small seeds are they close to the same habitatat? I could read up a bit I suppose. It seems everything else 'sabal' has bigger seeds. 

Is there a mid sized seed to match a species or is that more than likely a hybrid. I found one with seeds halfway in between on seed size but slightly larger than the range mentioned for Causaruium. And one I believe could be related to domingensis since the seeds are slightly larger and the leaves have more wavy bends?

Mexicana is confusing too! I think I found one with a huge almost 20 foot wide crown but with a palmetto sized trunk... and then another with an enormous trunk like a Causarium but maybe a 10 foot crown, both with large seeds. I'm sure there are hybrids and cultivars selected for traits growing all over the place... 

I suppose the nickname 'Puerto Rican Hat' has to do with the the the leaf shape but it's still confusing since all of these grow leaves that seem hatworthy... the trunk boots seem to be alot looser too I guess due to the width of the trunk pushing them out....

I saw mentioned that more sun will make the trunk shrink? That is similar to a feature of Sabal Palmettos which grow more densely in the crown when they are partly shaded

Edited December 7, 2020 by DallasPalms

[OC2Texaspalmlvr]

On 12/5/2020 at 4:57 PM, mnorell said:

I'm shocked this is not a landscaping standard throughout the 9a Gulf South. It would fill the "Bismarckia gap" for about 100 miles of real estate in from the Gulf.

I 100% agree with this statement. As much as we all love our Bizzies !! Causiarum are bullet proof in this area, grow faster and almost as visually appealing. Im gonna do my part to pass out as many of these seedlings as I can grow =) 

[mnorell]

10 hours ago, DallasPalms said:

This information is really helpful Thanks everyone. So I'm wondering since Sabal Palmetto trees also have small seeds are they close to the same habitatat? I could read up a bit I suppose. It seems everything else 'sabal' has bigger seeds. 

Is there a mid sized seed to match a species or is that more than likely a hybrid. I found one with seeds halfway in between on seed size but slightly larger than the range mentioned for Causaruium. And one I believe could be related to domingensis since the seeds are slightly larger and the leaves have more wavy bends?

Mexicana is confusing too! I think I found one with a huge almost 20 foot wide crown but with a palmetto sized trunk... and then another with an enormous trunk like a Causarium but maybe a 10 foot crown, both with large seeds. I'm sure there are hybrids and cultivars selected for traits growing all over the place... 

I suppose the nickname 'Puerto Rican Hat' has to do with the the the leaf shape but it's still confusing since all of these grow leaves that seem hatworthy... the trunk boots seem to be alot looser too I guess due to the width of the trunk pushing them out....

I saw mentioned that more sun will make the trunk shrink? That is similar to a feature of Sabal Palmettos which grow more densely in the crown when they are partly shaded

The seed size doesn't necessarily indicate a similar habitat. S. palmetto ranges from Cuba and the Bahamas up to the Carolinas. S. domingensis and S. causiarum are found in the greater Antilles east of Cuba but are possibly not too closely related to S. palmetto. If you read the monograph from Scott Zona, I think he gets into these relationships and the ancestry and development of the genus. What you note in your confusion over trunk sizes, etc. is why taxonomists and botanists use these types of indicators after the less plastic features...fruit and flower details are the most constant and reliable for identification; and at that point you can start using difficult little details like leaf scales, ramenta, etc. Leaf-size, trunk-size, etc. are so variable across populations of any given species, as well as their growing conditions, including all the crazy zone-stretching climates into which we plant them. Your palm is probably S. mexicana. Fruit can be 3/4" in diameter (maximum diameter, 1.9cm). From Zona's monograph: "Fruit spherical to oblate-spheroidal, black, with a thick pericarp, 14.8mm-19.3mm, 13.8-17.0mm high; seed oblate concave, 8.6-13.3mm in diameter, 5.4-7.44mm high, with smooth or protruding funicular remains; embryo supraequatorial, rarely equatorial." 

And the leaves of S. causiarum have long been used to make traditional hats in Puerto Rico, also woven into baskets and other like articles. Not to be confused with the Panama Hat Plant, which looks like a palm but is actually a cyclanth...and used to make...Panama Hats!

[DallasPalms]

This is the one I suspect to be a Causarium out of what I've seen. The seed size seems to match but with fruits a bit smaller than mentioned. They are all round also... I cannot tell if those are ligules starting out in photo #2?  I plan to go by and look every so often...

I'm about eye level with the bottom leaf... they are pretty good sized leaves but I did see one other with what appear to be leaves a bit larger than this one but on a smaller tree... will be fun to keep up with these to see which traits will appear... 

 

Edited December 8, 2020 by DallasPalms

[PalmatierMeg]

I doubt that is causiarum. It's too small. Mine flowered for the first time last year and I will need a ladder to reach the seeds. You have no idea how huge this species can be until you meet one in person.

[Collectorpalms]

22 hours ago, DallasPalms said:

This is the one I suspect to be a Causarium out of what I've seen. The seed size seems to match but with fruits a bit smaller than mentioned. They are all round also... I cannot tell if those are ligules starting out in photo #2?  I plan to go by and look every so often...

I'm about eye level with the bottom leaf... they are pretty good sized leaves but I did see one other with what appear to be leaves a bit larger than this one but on a smaller tree... will be fun to keep up with these to see which traits will appear... 

 

This last one appears as if you have stumbled upon a young Sabal Bermudana. They have a slight glossy leaf from a distance in the sun. They are actually one of the more cold hardy Sabals, they are pretty slow however. but attractive once they get 4-5 ft of trunk.

There is a young sabal Causarium at Mercer Arboretum ( there is a also a bermudana) on the north Side of Houston. The Causarium are not very leaf hardy, they start to crisp up at around 20F, They would not be hardy in north Texas. I have seen the one there burn.

Edited December 9, 2020 by Collectorpalms

[DallasPalms]

I bought some Bermudana seeds from an Ebay seller and the mother looked to be true even the baby leaves are turning out with blue shades... but the seeds were much larger? Those are around 1 Centimeter. I saw another beautiful palm today with smallish seeds and I noticed the boots leftover are much thicker where it was mostly shades in the early years and then at the top it turns into something closer to a palmetto grid... 

I think we have ALOT of hybrids here

I should read up on Bermudana they came in at about the same size as Texana Mexcana seeds... most sabals around town have around the same sized crown but this one photod below has an enormous crown maybe 18-20 feet wide... ruling out Causarium because the fruits and seeds are large size... this one maybe 15 feet tall.

We can competefl for Massiveness in Texas :-)

 

 

Edited December 9, 2020 by DallasPalms

[Stevetoad]

They are some beastly sabals. Here’s my son climbing ours. Notice the liguels. 

[ahosey01]

I have nothing of real value to add to this thread - just wanted to say @PalmatierMeg and @sonoranfans those are such cool palms in your photos.

[sonoranfans]

It could be that the ligules as dead matter can fall off in wind and not be so distinctive.  My sabal is not wind protected, its all alone with no nearby palms.  So while it has ligules, they are not very large.  In habitat it could be that high winds blow most of them off or that they dont persist in habitat as long as in cultivation.  Here is a pic of little ligules on my palm.  They are a little bigger near the bud but its hard to see the bud anymore as this palm has gone vertical the last couple years.   Maybe that is the reason Zona didnt identify ligules in habitat as differentiating, they dont persist and hence cannot be used to separate causiarum and domingensis.  So if you have big ligules it could be positive ID, but no obvious large ligules may not exclude causiarum.  

[sonoranfans]

[sonoranfans]

So in the above rsponse (to "ligules" a defining of causiarum) above by sarasota alex it is reported that some causiarum in habitat did not have ligules.  I think the characterization of fruit size as separating causiarum and domingensis has not been contradicted.  IF that was the case(no ligules on some causiarum) when Zona travelled there to collect samples, I would think he would not have reported a morphological characteristic that did not consistently differentiate these sabals.   He does say that the fruits did differentiate these sabals that he observed.

[DallasPalms]

I guess we have three primary Sabals in Dallas, big seeds, small seeds and Palmettos...

Causarium would fit well in Texas. Someone needs to cross with a large Texana for leaf hardiness

[DallasPalms]

Do Palmettos have ligules? My favorite Palmetto might actually be a Dominguensis... the already thick trunk has a little green still even high up on the trunk.

One of the popular sites mentions that the two coexist in Cuba (or one of the islands) and that Dominguensis is like a large version of a Palmetto?

Edited December 11, 2020 by DallasPalms

[DallasPalms]

lol I got excited and didnt realize the ligules are on the flower stalks

[DallasPalms]

Okay the photos from this thread put the Causarium/Domingensis group into perspective

 

[SouthFLA]

Sabal domingensis (Dominican Palmetto) at Arch Creek Park in North Miami, FL. Large trunk but no visible ligules. My wife and son in the photo for reference.

Edited February 22, 2021 by SouthFLA

[sonoranfans]

LOL that tree is so huge doubt you'd see ligules if it had them.  You would need a shot into the crown/bud area to show that.