Identify your species

Identify your species
29/9/17

Do you grow Sphagnum already and would like to know what species it is?

You can try to identify it, using Dichotomous key or write us to sphagnum@coxnature.com to send information about the origin (if possible the natural location) and the photos (very detailed, possibly with a macro camera). We will try to identify it.


Recognizing sphagnum species


Recognizing sphagnum species is not an easy task, for a number of reasons: The differences between one species and the other are often very small, except for a few cases The same species may have different characteristics depending on how it is grown, so as to make it in some cases almost identical to different species. To recognize with a good degree of certainty a species of sphagnum is necessary to follow several steps: First of all you have to try to get information about the location of origin of that sphagnum in nature, since some species live only in certain geographical areas. Without information about the location, most species cannot be identified with a good degree of certainty. Through the macroscopic analysis it is possible to recognize the section of belonging (the sections are 4 main groupings, Sphagna, Acutifolia, Subsecunda, Cuspidata, plus some small groupings that some authors also indicate as additional sections: Squarrosa, Polyclada, Rigida, Mollusca, Insulosa. Once the section has been identified, it is necessary to arm oneself with a microscope and hope that the characteristics of one's sample are clear enough to allow a unique identification. To understand what to look for you need to consult different sources. The most complete is a manual on the identification of sphagnum species of the late 80's, also provided with a good dichotomous key, but in the meantime the research has gone ahead, new species have been discovered, and some previously dubious species have been reclassified. Therefore, one cannot limit oneself to that source alone, but must also consult other publications. Recently (2018) another manual has been published, containing the cards of the 60 European sphagnum species, with the taxonomy updated, but it is less detailed than that of the 80's and tends to use an excessively differentiating taxonomy*, so it is not yet a valid substitute for the previous one. However, once an initial skimming has been carried out in the identification using the dichotomous key, we can find ourselves in front of 2 scenarios: 1) You are extremely lucky to have in your hands a species that is easy to identify, with all the characters that match both the dichotomous key and the descriptions of that species in the various publications. At this point it can be given an identification with a good degree of certainty. 2) In most cases, recognition by means of the dichotomous key reaches a dead-end, in which it is not possible to observe in a well-defined manner some characters that are crucial for identification. This leads to an identification with different candidate species (usually 2-3 but sometimes even 5-6). So you have to put aside the dichotomous key and consult the identifications of all candidate species to understand if, analyzing other characters, you can discard some candidate. Sometimes this is enough to arrive at an identification by "exclusion", i.e. recognizing a species not because we have seen some identifying character that has led to a unique recognition, but simply because all other possibilities have been discarded. Sometimes, however, even this is not enough, and the best thing is to put aside the microscope, arm yourself with a lot of patience and cultivate that sphagnum for a few months (better if a year) isolated from other species, and hope that, growing up and becoming more robust, it shows the characters necessary to finish the identification. In fact, the analysis cannot be carried out on sphagnum grown abnormally (for example, almost completely immersed, or excessively in the shade, or with an unsuitable substrate), but must be done on strong sphagnum samples, grown in excellent condition, so as to have developed the reproductive organs (unmistakable sign of excellent health of the sphagnum). In the absence of a good sample the analysis can still be tried, but it should be considered that probably in that case, what will be seen under the microscope will be different from what is reported in the publications. To understand how high the phenotypic plasticity of the sphagnum can be, I will give two examples where this phenomenon is visible even to the naked eye. The Sphagnum squarrosum is a relatively rare species in cultivation, but many people are convinced to have it because they notice the sphagnum with the ruffled leaves, typical, in fact, of the species squarrosum, when in reality, it is the Sphagnum palustre grown in conditions of low light and high humidity. In other cases, they tend to call any red sphagnum "capillifolium", or "rubellum", but, in most of the cases, they are other species more resistant and more diffused in cultivation, such as the russowii, which, in some conditions, tends to assume a red colouration almost like the capillifolium.


Another point should be made when you think you have a certain species in cultivation because when in the past you initially obtained that sample of sphagnum, it was indicated as a certain species. Sometimes it is a correct information, but often the truth is that the sample obtained contains more species of sphagnum among which "maybe" also the indicated species. This can happen because that precise species has perhaps become extinct in the culture from which the sample was taken, and has been completely replaced by the others. For example, there are some wholesale sphagnum suppliers (who grow it on managed peat bogs), who indicate their product as "cristatum della nuova zelanda" or "magellanicum del cile", or fuscum, etc... or you get sphagnum that was originally from a sample taken in the wild at a peat bog where most of the sphagnum belongs to a certain species. In both cases, the sphagnum comes from peat bogs in which many other species coexist, of which perhaps the one indicated is present in greater percentage, but rarely these are monospecific crops. If you buy directly from the wholesaler then you can have to deal with a mix of species, including the one indicated on the label, but if you receive the sphagnum from subsequent steps, inevitably the effect "bottleneck" may lead to have a species different from that indicated, especially if the sphagnum has been grown in conditions that favor one of the other secondary species of the lot. The same is true if the sphagnum is obtained from a cultivator who, maybe, has initially obtained a certain species with a good level of certainty, but who has then cultivated it not isolated from other species, with which it has inevitably mixed, because the sphagnum rarely likes to live in monospecific cultivations: more species together tend to live better. To conclude, having a multi-species sphagnum culture can be simple, interesting and satisfying, but giving a name to the various species composing the own culture is not so easy. And, above all, if we want to have a collection of species of sphagnum, once we have obtained some sphagnum of a certain species with a high margin of certainty, we have to cultivate it isolated from other species in order to avoid that we lose the identity of our own cultivation. As far as non-European species are concerned, there is still a lot of chaos, as it has not been possible to sort out old and new identifications, and it seems that there are no publications summarizing the species of a given area. Probably in the next few years we will get some order and discover that the 240 (and more) species of sphagnum described are actually many fewer species, with many geographical variations. *for example, by subdividing in 3 different species what for many authors is considered to be a single species with a lot of phenotypic plasticity (Sphagnum fallax, subdivided in fallax, isoviitae, brevifolium, for the cuspidate section, but in a lesser way there is some confusion also with other species of other sections).


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