Any evidence of pores?

I think they look like grass pollen, but it's hard to tell without focusing up and down. I'd be looking for starch grains and a single pore. When and where were they collected?

The photo is not very clear but they could pollen of seed plants; e.g. pollen of Populus sp is 25-35 micron in diameter.

Perhaps these are starch grains.

The two 'things' at right may be pollen grains of Ulmus (verrucate exines, and possibly pores only along the profile); the other may be a pollen of Poaceae, grass pollen, that has a smooth surface (scabrate) and one pore (not visible).

You should take pictures at higher magnifications, or use less staining color to not cover the surface and apertures of pores, if possible.

I think these are pollen grains, if you amplified the picture you can see the pores. The first one in the right with smooth exine could be Poaceae and the others two are differents, they seem to have two o more pores and the exine is reticulate.

It would be interesting to know what they looked like without the stain. If they were brownish before stain, I might guess smut spore.

I think I see a sulcus on the middle grain, like one of three on an oak pollen grain. But, I agree with Landon.

Mycorrhizal spores?

Not easy to identify in this conditions (photograph, magnification and staining), but those seem to be pollen grains. To me, the two at the upper right seem to be Populus sp. pollen grains and the lonely one at the left of them seems to be a Poaceae pollen grain.

(after reading other answers, I agree that the two grains at the upper right can also be Ulmus sp.)

Pollen grains.

Pollen grains.

I'm agreed with Anna Marie Mercuri.

Two grains up are maybe Ulmus and the down on the left is a Poa.

Parecem ser grãos de pólen e todos da mesma espécie. Seria interessante prepará-los com solução acetólise para observar melhor a exina.

You can see more pictures in the attachment file, thanks!

I agree with Diana Obregon and Maria Garcia, these are definitely pollen grains. I just don't think they have reticulate surface, maybe microreticulate or scabrate. It is hard to say for sure, as the grains still have their cell content (need to Be acetolyzed). Where is this sample from? You could check the airborne pollen forecast of the region. Cheers.

Yes! I agree with Ana María Mercuri. These grains are Poaceae (the only one at the left) and Ulmus (the others two at the right).

I agree with all the other researchers'. These must be pollen grains belonging to Poaceae and Ulmus.

Clearly are pollen grains (charactheristic pollen wall). For belonging to Poaceae, teh pollen wall is too thick but it's true that there is a pore light presence. I don't see clearly Ulmus pollen, but other Ulmaceae species, can be. It is necessary do the acetolysis and know the región, like Mauro says. Sorry for my english (@olalla63)

When pollen is captured by a spore-trap, it is included in silicon oil or similar sticky substance, over a plastic film, and cannot be subjected to the acetolysis treatment. As the morphology of fresh pollen is different from the acetolysed one, the reference pollen collection should include fresh pollen (with cytoplasm) collected from the local flora.

I agree - pollen grains: Ulmus (the two at the rigth) and possible Poacea

From my personal point of view a reliable identification of those three objects based only on the given picture and the staining reaction with Lactophenol-cotton blue is not really possible. It would be necessary to know the position and numbers of apertures and their structure and more about the wall features. Beside Ulmus or Zelkovia also some Plantago species or also Litorella produce pollen grains resembling the upper to objects. Possibly you may have additional/different taxa in the flora of your area. If the third object has an accordingly structured pore it is a Poaceae, but without that information it could be even a spore for instance.

Those are pollen grains, however the apertures and sculputure are traits difficult to see, so the species plant from which it comes is not easy to identify.

Rajiv,

Some suggestions:

-Take additional fotos at different focal levels.

-Search for apertures.

-Avoid staining.

-It needs more details about the phytogeographical envirornment of the area of specimens obtention.

I hope you will have success.

Monika Barth

the two at the right are probably something like Ulmus,

the one at the left may be Fraxiunus (this is what the shape tells me). - Look for a reticulum while focussing through the grain.

And generally, avoid staining in such an intensive manner.

My suggestion is: no staining.

After you have one two, three years of experience on "no stain", you may select a method of your convenience.

I do not believe in "Poaceae" in this case.

kr

Siegfried

I agree that the two on the right of the picture look somewhat like Ulmus at first sight, but there are no pores in clear view and, actually, the grains look marginally small. I am not convinced that the grain on the left is Poaceae. It might be better to stain with very dilute safranine than the one you have used. Of course you do not need stain if you use phase contrast microscopy.

I agree with Anna. I thought the same thing before I even saw Anna's answer. And for the same reasons I would suggest Ulmus (Elm tree pollen in common English)...the surface texture of the two cells on the right...although I would call it regulate not verrucate, and the size and the pores and the shape of the cells, stephanoporate (pores arranged around the equator of the flattened grain). The thickness of the wall agrees as well. The grain on the left could be grass pollen...again as with the other two cells on the right it has a thicker wall suggesting pollen and not algae or some other spore. Its surface texture appears to be psilate (smooth). I don't see a pore, but there maybe a hint of one at about 9:30 on the grain if you imagine a clock face and where the hour hand might be at that time. Anyway, without having the sample right here I can only conjecture. Oh, the fact that there is a dark interior suggests the presence of cytoplasm inside the cell wall. That is why they are so difficult to see clearly in this photo as well.

Pollen grain having psilate surface but pores are are not visible it may be a pollen of poaceae after confirming the presence of single pore

If identification of these is very important, one should record them as "unknowns" because the identification is ambivalent. They look a little bit like Ulmus (elm) and Poaceae (grass) but one cannot be sure.

I agree with many of the other posts. The intensity of the stain is making it impossible to see the apertures and the exine surface. I also agree that the two on the right could be Ulmus and the one on the left Poaceae. Even with the overstaining, it should be possible to locate apertures with careful focusing.

Rajiv,

I agree with Anna. The three particles are not airborne spores but pollen.

The two uper pollen grains are likely elm (around 30-32 microns in diameter with a characteristic exine). As also Anna mentioned, the particle on the left could be a grass pollen, with a diameter size that can be similar to that of elm pollen in some instances, depending on the species. I imagine that you took the photo under 400X.

I would recommend you to use Calberla's solution (basic fuchsine) to stain the slide and also provide information about the season of the year when the sample was collected.

Regards,

Rosa Codina

You have mentioned in your question that 'These are air borne spore'. But it is difficult to identify on the basis of this much information. They may be pollen grains or fungal spores that are found in the air.

To confirm you must visualize the vegetative form of it, and for that appropriate propagation media is to be employed.

Only staining with lactophenol and visualization will not help. you need to refer standard monographs also.

I agree with all above answers.

I agree with Anna

Nice to get so many suggestions from experienced peers.

Nevertheless, Ulmus and Poaceae are unlikely simulaneously in the air .

I insist on my suspicion thinking Fraxinus being the best solution for the grain to the left..

The upper two: Ulmus or Zelkova seem to be most propable for the other two at top. I imagine to see an aperture on the middle grain short before six o'clock. The outline is rugulate. Size fits.

The puzzle can't be solved unless more details can be provided. Ulmaceae is most probable.

grain to the left:

pro Poaceae: smooth exine.

con: no Porus visible, no circular shape

pro Fraxinus: outline ovoidal, a glimpse of columellae in the exine. Eventually some evidence of colpi at 4 and 8 o'clock, no porus detectable.

con: no reticulum,

expertise: it is Fraxinus - no Poaceae (I have experience of more than 30 years of daily analysis of air samples). Could be Acer, but Colpi are too narrow. Could be Populus, but intine is too thin.

kind regards,

Siegfried

I must to rectify my answer and support the answer of Siegfried Jaeger. I know that he is right because I was one of his student in an Aerobiology course.

:-)

I do not believe that you cannot have elm and grass in the air at the same time. In fact, I know that that comment is wrong. Don't forget that pollen can be residual and redistributed from previous seasons. In my work, these grains would have to be ignored because one cannot be 100% of their identity. It is not good enough if there are doubts.

Siegfrid, I have to respectfully disagree. You can have Ulmus and Poaceae in the air at the same time. Our spring pollen season in Tulsa was late in starting, so we had Ulmus pollen in the air through 13 April. From 1 to 3 April and then again from 8 April through 13 April both Ulmus and Poaceae were registered in our Burkard sampler.

Estelle,

Many thanks for your comment.

I can't deny that Poaceae and Ulmaceae couldn't appear altogether in an air sample.

The feasability is nevertheless lower than .....

As we do not know time and location of the sample taken, it was (also due to the curious staining) only a matter of suspicions.

My advice is to cease now discussions about the request unless new information will be available.

Siegfried

In relation to the surface area of land which supports these plants, the number of recording points is miniscule. It is unwise to make such sweeping remarks about such possibilities because so much is unknowable. In Britain, you can always find a few grass plants flowering whatever the season. Aerobiologists can only sample a very small part of the airspora.

Mrs. Miltshire's answer is so far correct and I can agree to some extent.

In fact, somebody primarily asked for much less:

the question was not WHICH pollen grains have been displayed, but WHETHER OR NOT the particles are biogenic - pollen or spores

A storey below what we have been discussing in terms of allocation of Poacaeae or not.

No news. My statement remains the same

Siegfried

The former may be grains of Ulmus, but in the case of having the smooth exine, I do not think Poaceae, since it is not at all the existence of the pore and the wall gives the feeling that it is too thick.

Its ovoid shape without opening reminds me rather a Cupressaceae Juniperus pollen, or even a Taxus.

Anyway, I agree with Anna. You should take pictures at higher magnifications, or use less staining color to not cover the surface and apertures of pores, if possible.

What is real, we do not know the origin of the sample and the floral calendar by region, because, as our colleague says, the same plants vary greatly in their flowering season and even in the amplitude of the flowering period, as the climate of the area, who lives in soil and other parameters. This is clearly seen in a country like Spain, with large climate variability and the different behavior that can have the same type of plant.

My opinion is that we should wait for more data.

Amelia

Indeed it is very difficult to identify the particle, If we refer to the scale diameter of it (about 20µm), Is this size could be found in Poaceae, Ulmaceae or Fraxinus of origin zone? In my experience it is least probable.

Perle Ramavovololona

The stain is very dark but the two nearby pollen at right could be Ulmus and the one at left can be Poaceae (as also suggested by Anna much before). For size its always good to set scale of 20 or 25 micron while taking pictures of spores-pollen.

I agree that the two at the right are more than likely elm. However the oval one on the left to me looks to oval for ash or Fraxinus. My guess would be a grass or poplar. It is a bit early for grass with elm. That depends on where these are taken but here in Canada poplar and elm are more likely to occur at the same time.

These are actually pollen grains and not spores. However, the colouration was much and could not allow for proper identification. Anyway I think Anna is right, but the pollen to the left as she said is not Poaceae because it is not a porate grain.

Use saffranine when staining, it allows for a better micro-morphological examination.