Is this Dioon Merolae?

[Brian]

I purchased two of these in Acapulco over the weekend. An opinion on their ID by the experts out there would be highly appreciated.

Regards,

Brian

[Brian]

Here's a photo look down at the plant

[Brian]

The second plant doesnt have leaflets going all the way down.

Thanks for any ID you can give,

Regards,

Brian

[LJG]

No expert of course, but I think these are Dioon Spinulosums. Lets see what others think.

[Brian]

Thanks Len. Thats what the nursery called it but they looked so much different then the Dioon Spinulosums that I have. Are there different varieties?

They seems to have thicker and wider leaflets, a greener color with more spines.

Here one I already had,

Oh well, I guess you can never have enough!

Regards,

[LJG]

Dioon rzedowskii and Dioon Spinulosum are tough to tell apart. I usually wait until it flushes. If it has a bunch of tomentum on the new leaves, it is Rzedowskii. I know that they say Rzedowskii also do not have armed petioles, but nether does a stretched juvenile Spinulosum. One last thing on that second plant, is it has marginal spines (serrated), which they say is a characteristic of Spinulosum.

I am sure Jody or the other Cycad guys will be buy. But I am 99% sure it is not Merolae. Maybe you meant Dioon mejiae?

[tropicalb]

Agree with Len....the first and second pictured dioon is spinulosum....the third pic looks like a very stretched out spinulosum....the one you already have in the fourth pic looks like merolae. Jody would know for sure though.

there are MANY different types of dioons. Very underated cycads IMO.

[virtualpalm]

The first two plants pictured above are Dioon spinulosum, with the second plant being younger than the first -- and, hence, having a bare petiole. The third plant pictured is Dioon mejiae (from Honduras), which might explain why your new plants don't look like those that you already had.

For more information on identifying the various species of Dioon, two of my colleagues and I created a poster that should help. You can view a PDF of the poster, or even order your very own copy, from the Cycad Society website: http://www.cycad.org/publications/Dioon-poster.htm.

Jody

[Brian]

Thanks guys.

Jody, the Dioon key poster is definently what I need. Thanks for giving me the heads up on how to get it.

Regards,

Brian

[LJG]

Jody, I just bought the two posters. Your PayPal integration did not ask for shipping details or my name. So if you see an order for Vista, it is for "Len Geiger" and the address it was under was for the business.

[tropicalb]

Jody...

What threw me off on id'ing that close up picture of that plant as a mejiae was that i have never before seen one with leaflets that are that thin and somewhat cupped like the one pictured.

Could you tell me what's the giveaway that it's a mejiae? The rib?

[virtualpalm]

Could you tell me what's the giveaway that it's a mejiae? The rib?

Burt,

This is really a "gestalt" thing for me, so it is a bit difficult to explain to others how I came to that conclusion... but I will try.

The leaflets of Dioon merolae are actually quite a bit narrower than those in the photo. They are also much more closely spaced, overlapping, and imbricate -- so as to make them look like a Levalor blind. Finally, the leaflets of D. merolae are declinate (curving downward), falcate (curved in a sickle shape and pointing toward the tip of the leaf), and not decurrent (leaflet base extending downward along the rachis). Although D. mejiae usually has entire leaflet margins, it does sometimes have a few small teeth on the upper or lower margin -- particularly on younger plants. As for the rib running down the top of the rachis, D. merolae also has one, but it is more flattened and not as noticeable.

I don't know if this helps, but there it is.

Jody

[tropicalb]

Helps a lot....thanks!

When plants are immature, especially with dioons, it seems very difficult to tell the difference between them. For example, I've had people show me seedlings they thought for sure were D. califanoi, and three leaves later find out that they were actually merolae. And the opposite has also occurred!

It's also hard (for me at least) to tell the difference between D. rzedowskii and mejiae....even in plants that are older and more mature.

[virtualpalm]

Burt, have you studied the key that is part of the Dioon poster? The poster also has representative photos that illustrate each couplet in the key. That should provide some help... if not, let me know and I will try to explain it.

Jody

[tropicalb]

while the poster is VERY helpful Jody....the pictures of leaf structure and of the plants themselves (not unlike those in Loren's GREAT book The Cycads) all seem to be of more mature plants. I think, in addition to your poster, what would be helpful to most people involved with getting started in growing and collecting cycads in general would be pictures of leaves in the earlier years of the plants development, as well as pictures of seed.

That being said, the Dioon poster and the Cerat poster are most certainly great references for any serious collector of cycads.

[tropicalb]

Ack!

I just realized I spelled Loran Whitelock's name wrong in the above post (actually, it was an honest mistake, as my father-in-law's name is Loren spelled with an "e").

He is the author of "The Cycads".....a must-have book for anyone interested in cycads.

[Phil]

Brian,

Definitely not Dioon merolae. Agree with comments above. Here's photos of the leaves of merolae.

Phil