This has always evaded me...and I have never found side by side comparisons. I have tryied for years to find definitive info on telling one from the next but I can't, the best I can do is find descriptions and compare them, but all are so similar...
I have made lots of speculative observations on the plants I've owned over the years... But just don't know how to tell the 3 from one another, I hate spreading misinformation, so I would love to be able to id them with 100% confidence...
If anyone knows, or could link me to something I haven't found yet that would great!

A. odora and A. x calidora are so similar that, even for me, it is like telling twins apart. Yet I can do it because calidora is one of my babies. However, those two can be told apart from macrorrhizos very easily, especially if both are blooming. Odora/calidora blooms have a matte look, the spathe does not flop back on pollen drop and blooms, overall, appear bluish-green, while blooms on macrorrhizos don't have the matte look, usually are longer/taller, and the top part of the spathe flops down when it is time for pollen drop. Bloom odor is somewhat pleasant on odora/calidora while on macrorrhizos, it is somewhat pungent and unpleasant.

Mature leaves on macrorrhizos have no leaf tissue between the "ears" (where the petiole joins the blade) while odora/calidora have leaf tissue between the "ears". This rule only works to distinguish these two groups; it won't hold up for other Alocasia types as there are non-macrorrhizos types with no leaf tissue between the "ears".

Hope this helps,
LariAnn

Thanks alot lariann, my question was generally directed at you...

I fail to understand ur explanation about mature leaves tho, do you mean then is leaf material in the sinus? Between the anterior lobes?
I thought so at first, until I reread it a few times, now I'm unsure...

I don't have A. Mac anymore, my flowers don't stink! But it doesn't seem to match the description of odora flowers either, tall, green, not glossy, but barely matte...

I got it from a freind, he got it from a freind, we've lost contact will that guy, he was apparently an EE nut too... Are there any other options, besides the 3 I mentioned, that could be legitimately confused with odora?

Also I'd love to be able to tell odora from calidora, I have an astut eye for detail... Any tips there, Lariann?
I'm sure if I knew how I could, even if the difference is very minute!

The reason I referred to "mature leaves" is because in many, if not most, Alocasias, the seedlings or juveniles have leaf tissue connecting the two "ears" on the leaf. As they mature, odoras keep some tissue there but macs lose it altogether. In a typical EE, there are only two "ears" or lobes, so to refer to them as "anterior" would imply that there is a "posterior" set as well, which there isn't.

As far as other species that could be confused with odora, for one, there is A. wentii, which has peltate leaves (so much leaf tissue between the ears that the ears are hardly distinguishable as separate ears anymore). However, bringing that up opens a can of worms because the blooms on A. wentii look and smell just like odora blooms! Sorting that issue out will require some scientific investigation.

One way I tell odora from calidora is that in odora, the leaves are nearly completely smooth between the veins. In calidora, there is some degree of puckering or wrinkling of the leaf tissue between the veins. I cannot say that this is a sure-fire diagnostic for telling the two apart, but if I were shown two plants and told that one was odora and the other was calidora, then asked to tell them apart, I could do it.

If have a calidora F2 with so much puckering between the veins that I call it "calidora bullata". It is smaller than the calidora on the market, but thicker looking overall.

Hope this helps,
LariAnn

Very much help indeed!
I'll formulate a proper response soon.
Thank u very much

I swear it didn't take 2 years for this to sink in! but I do feel like it's a never ending journey of learning, wrapping ones mind around the complexities of this genus!
Any way 2 years later... I find a mature mac.!
I spotted it from almost a block away and pinned it as different from what I've always grown!

It looks pretty rippled, the way a Borneo giant is known for, I wonder what it is... I guess I better just try to get it...
That way I'll know for sure





A perfect V, no leaf between the lobes at all!

@lariann
To further clarify, when you say that this lack of sinus leaf tissue rule doesn't hold up to other non mac. types, you simply mean that just because an alocasia doesn't have leaf in the sinus, that doesn't inherently mean that plant has mac. In its lineage. Is that what you meant?

What you wrote is correct, but also that just because a plant lacks blade tissue in the sinus doesn't mean it is automatically a mac or mac derived plant. A. sarawakensis has no blade tissue in the sinus but it is far from being a mac, being more closely related to the jewels than to mac. Besides, no mac has fine short peach fuzz on the petioles like A. sarawakensis does.