יומן של Schoenus in southern Africa

Over the last few years, I have been compiling clear, illustrative images of key traits of southern African Schoenus species to use in Wikipedia and Wikispecies pages. This has allowed me to give a more detailed description of each species for future reference. Recently, I have been opting to include images that already have their permissions set to CC BY-SA 4.0 so that I don't have to ask people to change their permissions for me to use their images.

As one can imagine, this has created a situation where species with many observations on iNaturalist have lots of detailed images on their webpages, while less observed species are lacking images.

The following is an update of additional images that I am looking for to improve webpages:

The next group of species already have images uploaded to their webpages, but these could be improved for illustrative purposes:

Big strides have been made in the last couple of years in finding some of the southern African Schoenus species with relatively few observations. It was especially exciting to see observations of S. filiculmis, S. rigidus, S. aureus and what I think is S. adnatus when reviewing the almost 600 observations uploaded to the project.

If you are heading east of Knysna, keep your eyes out for the large S. loreus, with its flat leaves. Schoenus limosus is also large and tends to occur in muddy locations in eastern South Africa.

I am really surprised that we have yet to see any S. lucidus. It is quite a robust former Epischoenus species that one can find up in the mountains of the Worcester and Ceres regions.

I admit that there could have been some S. brunnescens observations already submitted, but this is a species that stands out more in the field than it does in on a herbarium sheet or perhaps even an image. It seems to be closely related to S. compactus and S. crassus, but has much shorter spikelets.

I know that some of you have had your eyes out for S. calceolus in the limestone areas of the Overberg. This species is more like S. bolusii than S. cuspidatus/S. crassus. It is small, with short spikelets and can have a unique flattened base.

The lack of observations of S. triticoides and S. riparius does not surprise me. These are species with very narrow known ranges. Schoenus triticoides is a very unique species in the Schoenus compar - S. pictus group, whereas S. riparius seems to be a more robust version of S. cuspidatus. I sometimes wonder if the collections of S. riparius were only autopolyploids of S. cuspidatus.

Schoenus: 598 observations by 116 observers

1127 identifications by 36 identifiers

• 432 observations (73%) are Research Grade
• 31 observations (5%) need a confirming ID (help confirm them here)
• 75 (13%) are identified to subgenus-complex (help review them here)
• 58 (10%) are identified to genus (help ID them here)

Some 37 species recorded.

Topmost recorded species:

136 Schoenus compar Ivory Veldrush

52 Schoenus cuspidatus Sharp Veldrush
30 Schoenus nigricans Black Veldrush
30 Schoenus graciliculmis Delicate Veldrush

25 Schoenus auritus Fleshy Veldrush
23 Schoenus gracillimus Slender Veldrush

18 Schoenus pseudoloreus Eared Veldrush
16 Schoenus megacarpus Bignut Veldrush
11 Schoenus ligulatus Strap Veldrush
10 Schoenus pictus Yellow Veldrush

9 Schoenus exilis Small Veldrush
9 Schoenus quadrangularis Square Veldrush
8 Schoenus compactus Congested Veldrush
8 Schoenus crassus Robust Veldrush

7 Schoenus graminifolius Grassleaf Veldrush
7 Schoenus arenicola Sand Veldrush
7 Schoenus australis Southern Veldrush
7 Schoenus selinae Auricle Veldrush

6 Schoenus neovillosus Hairy Veldrush
6 Schoenus prophyllus Bract Veldrush
6 Schoenus inconspicuus Hidden Veldrush
5 Schoenus bolusii Spotted Veldrush
5 Schoenus complanatus Flat Veldrush

Most observations (more than 10):

1 tonyrebelo 95
2 douglaseustonbrown 69
3 botaneek 69
4 mr_fab 40
5 nicky 21
6 vynbos 20
7 karooicus 17
8 dhoare 15
9 chris_whitehouse 14
10 tle003 12

Most species observed (more than 5):

1 douglaseustonbrown 26
2 botaneek 21
3 tonyrebelo 14
4 mr_fab 14
5 tle003 8
6 chris_whitehouse 7
7 nicky 7
8 vynbos 6

Most identifications (more than 10):

1 tle003 510
2 sedgesrock 199
3 douglaseustonbrown 155
4 tonyrebelo 135
5 venturefoth 18
6 jeremygilmore 18
7 rvanmazijk 16
8 botaneek 14
9 gigilaidler 11

I have some good news!

We have a new article out:

I recently published an article in Annals of Botany, with Muthama Muasya and Petr Bureš on polyploidy in southern African Schoenus. The interesting part of this article for those that are contributors to the Schoenus in southern Africa iNaturalist project is that we used many 'Research Grade' observations in this journal article.

In short, we supplemented our own field observations with those from iNaturalist in cases where we were confident in the identifications and the ploidy levels of the different species. These observations allowed us to address research questions related to how genome size and ploidy level (e.g. diploid / polyploid) are related to the environmental growing requirements of many species of southern African Schoenus.

Article name: Complex patterns of ploidy in a holocentric plant clade (Schoenus, Cyperaceae) in the Cape biodiversity hotspot
Authors: Tammy L. Elliott, A. Muthama Muasya and Petr Bureš
Journal: Annals of Botany; https://doi.org/10.1093/aob/mcac027

It is always pleasing for me to find more Schoenus observations posted on iNaturalist. For one reason, the understanding of these species and their distributions is improving. We are also getting a better understanding of the habitat preferences and the morphological traits associated with each species.

Research-grade observations of Schoenus are also important for me, because I can easily export the data from iNaturalist and incorporate it into my analyzes. Often researchers use data from repositories such as GBIF (https://www.gbif.org/) for this type of research, but it is much more difficult to check the observations to make sure they are accurate using that platform. While it might not matter that much for analyzes at the global scale, for local- or regional-scale analyzes, such as those focusing on southern Africa, it is preferred to have more accurate, checked data. iNaturalist can supply that data.

Your data will be very useful for a paper that I am currently preparing on the connection between genome size/polyploidy and the niche requirements of different southern African Schoenus species. I could always use more observations for my analyzes - so the more high-quality observations - the better!

Thanks again for everyone's contributions.

It is time for an update on the race to find different Schoenus species. I have created many Wikipedia pages to help with the identification of the southern African Schoenus species, as well as to give you an idea as to where they can be found. Please refer to them if you need to. You can always ask me if you want to find out more information.

Good-luck with the hunt and don't hesitate to drop me an e-mail message if you need any help.
Tammy

You will sometimes notice that your images have been identified not to species, but to one of three main groups of southern African Schoenus. This might lead to you questioning: 1) what are these three groups, 2) which species pertain to them, and 3) why are they referred to as groups? I will provide you with a brief explanation.

Schoenus "compar-pictus" group

This group contains some of the most conspicuous southern African Schoenus species. Distinguishing characteristics include:

• dilated primary inflorescence bracts or membranaceous marginal extensions on the bracts. These bracts either partially or entirely cover the spikes;
• sheaths and ligules that are usually open and membranaceous; and
• many species in this group have sticky culm bases and flowering heads.

The two images below show Schoenus compar (sticky) to the left and Schoenus pictus (dilated primary inflorescence bracts) to the right:

More detailed images of this group of Schoenus can be found on the following websites:
https://en.wikipedia.org/wiki/Schoenus_compar
https://en.wikipedia.org/wiki/Schoenus_megacarpus

Species in this group include:
Schoenus compar, Schoenus arenicola, Schoenus pictus, Schoenus pseudoloreus, Schoenus aureus, Schoenus megacarpus, Schoenus comparoides, Schoenus albovaginatus and Schoenus triticoides.

To date, Schoenus filiculmis is considered in this group, but several characters and preliminary phylogenetic analyses show that this placement is doubtful.

Schoenus "cuspidatus" group

This is the group with the highest number of southern African Schoenus species. It is a confusing group, with a lot of intermediate forms suggesting possible hybridization. Species in this group have leafless flowering stems and a characteristics spikelet with a distinct prophyll.

Detailed images of the characteristics spikelets are shown on here:
https://en.wikipedia.org/wiki/Schoenus_cuspidatus
https://en.wikipedia.org/wiki/Schoenus_bolusii

This is the most species-rich of the three southern African Schoenus groups. Based on current knowledge, the species in this group include:
Schoenus auritus, Schoenus graminifolius, Schoenus ligulatus, Schoenus exilis, Schoenus bolusii, Schoenus submarginalis, Schoenus crassiculmis, Schoenus purpurascens, Schoenus prophyllus, Schoenus calceolus, Schoenus quartziticus, Schoenus limosus, Schoenus brunnescens, Schoenus compactus, Schoenus crassus, Schoenus loreus, Schoenus galpinii, Schoenus riparius, Schoenus cuspidatus, Schoenus graciliculmis, Schoenus australis and Schoenus inconspicuus.

It is unclear at this time whether Schoenus bracteosus pertains to the "compar-pictus" or "cuspidatus" group.

Schoenus "Epischoenus" group

Species in this group used to be placed in the genus Epischoenus. They are generally associated with wet habitats and lack leaves on both their flowering stems and bases.

Three examples of species in this group are described on the following pages:
https://en.wikipedia.org/wiki/Schoenus_quadrangularis
https://en.wikipedia.org/wiki/Schoenus_neovillosus
https://en.wikipedia.org/wiki/Schoenus_gracillimus

Species included in this group are Schoenus complanatus, Schoenus quadrangularis, Schoenus selinae, Schoenus rigidus, Schoenus crinitus, Schoenus adnatus, Schoenus schonlandii, Schoenus lucidus, Schoenus neovillosus and Schoenus gracillimus.

Schoenus dregeanus is an odd species that has characters intermediate to the "cuspidatus" and "Epischoenus" groups.

Why groups and not sections or clades?

This is a decision I have made based on the available evidence. At this time, there are still a few species which are impossible to place with certainty (e.g. Schoenus bracteosus, Schoenus filiculmis and Schoenus dregeanus). In addition, there could be gene exchange among the three different groups, meaning that they are not completely delineated from each other.

Another reason is that I do not see a reason at this time to keep dividing and dividing.

Best of luck with the hunt!

Over the last year and a half, I have been creating Wikipedia and Wikispecies articles for the southern African Schoenus species. For each species article, I have tried to include species descriptions, a brief taxonomic note and some information on the distributions and key habitats. When possible, I have incorporated images from iNaturalist contributors and myself to help describe the species. I have also included a distribution map for each species to give readers an idea of where a species might be found.

The intention for these pages is to make it easier to identify and understand these difficult-to-identify and complex species. This is a 'work-in-progress', as I realize that improvements can always be made, especially with image quality. Ideally, I would make a digital key available to help you identify your specimen. Then, you could google the species name and see the Wikipedia page to double check your identification. Hopefully, the time will one day be available to do this.

Wikipedia
https://en.wikipedia.org/wiki/Category:Southern_African_Schoenus

Wikispecies
https://species.wikimedia.org/wiki/Category:Tammy_Lynn_Elliott_taxa

I still have yet to create articles for seven species whose names are still being processed through important taxonomic name databases. (Schoenus australis, Schoenus brunnescens, Schoenus graciliculmis, Schoenus inconspicuus, Schoenus crinitus, Schoenus selinae and Schoenus rigidus).

Thanks to all of those who have given me permission to use their images posted on iNaturalist during this process.

Tammy

Similar to grasses and other grass-like plants, Schoenus species can be very difficult to identify even with the use of a high powered microscope. Photos, such as those posted on iNaturalist, can be useful in identification, but they generally have to show some key characters with fairly high resolution.

Generally, photos should focus on the following characters:

1) HABITAT: Is the environment where the plant growing wet, dry, flat, on a mountain slope, for example? If possible, a photo showing the general environment with neighbouring plants can be a helpful clue.


In the left photo, the species is from a wet draw, which is a clue that it might be from the former Epischoenus group or Schoenus ligulatus. The species to the right is from a drier location in a mountainous habitat.


2) GROWTH FORM: How tall is the plant? How big is the tuft? Most Schoenus species will form clumps, but some species (e.g., Schoenus gracillimus) can be spreading.

The plant in the left image is somewhat spreading, whereas the growth form in the plant to the right is tufted. The tufted growth-form is very common in this group.


3) INFLORESCENCES: These are the flowering heads. A CLOSE-UP image of at least one flowering head is imperative for identification. The individual spikelets making-up the flowering head will ideally be in a mature form, but not too old.

The overall form, length and width of the inflorescence is important when making an identification, as well as characters such as whether the inflorescence is sticky or if it has auricles (membranaceous 'flaps'). If one looks carefully at the image to the far left, you will notice that it is sticky (characteristic of some species in the Schoenus compar - Schoenus pictus group). The image to the far right has a membranaceous flap at the base of each individual flowering head. This character can be hard to see since these flaps are rather transparent.

4) SPIKELETS: These are the composite of flowers that are the individual parts of the flowering heads. They can be very difficult to focus in on with your camera, so sometimes it is best to pick them off of the flowering heads and take a picture of them on a piece of paper. It is even better if you have a small ruler to function as a scale.

A high quality view of the spikelets is often very important in making an identification. Important characters include length, width, and shape. Spikelets have glumes which are the bracts associated with the individual flowers. If you zoom into the image on the right, you will see that there are about four to six glumes for each spikelets. Another important character of the glumes is whether they have reddish-purplish spotting, such as the Schoenus bolusii image to the right.

The image of the spikelet on the following Wikipedia page illustrates spikelets with glumes in more detail: https://en.wikipedia.org/wiki/Schoenus_arenicola


5) BASES OF FLOWERING STEMS: This is not the nicest image to take, because it often involves removing a little bit of the plant from the ground. The process can be a little dirty and won't result in the prettiest picture.

The left and middle images were taken from plants with membranaceous bases, whereas the bases of the flowering stems are more firm in the species in the right.


6) NUTLETS: Photos of the fruits of Schoenus species are useful in identification, especially for species such as Schoenus exilis; however, mature nutlets are not always present on a plant. If you can isolate a nutlet in the field to get an image - GREAT! It will be appreciated.


I thank Doug Euston-Brown and Nicky van Berkel for supplying images for this blog post.


ADDITIONAL RESOURCES

Over the last two years, I have been making a series of Wikipedia and Wikispecies pages which includes images of key characters. This process is ongoing, and I am still not able to make some pages because the respective names still haven't been passed through all of the important nomenclature databases. However, several of these pages exist and show some important illustrative images of key characters, such as spikelets, nutlets and close-ups of flowering stems.

Currently, the best way to access these images is by typing the species name into your web browser.


Good-luck with the hunt!

Can you find the rare species?

While we have hundreds of observations of southern African Schoenus on iNaturalist, many of these observations are of the most common species, such as Schoenus cuspidatus and Schoenus compar.

Now it is time to add observations of some of the more rare species to iNaturalist. I have collected a majority of these species, so don't hesitate to contact me if you would like so clues on where they might be found.

The remaining species already have several observations on iNaturalist, but that being said, it would be great to see even more to help gain a better understanding of their distributions. These are the species that many of you might already be familiar with.