Journal archives for December 2021

December 03, 2021

Milestones and meta-data

I noticed I haven't posted anything in my journal for a while, so I guess it's time for a bit of a recap! (Also, it's final exam week so naturally I'm looking for something to distract me from grading...) It's been a little over two years since I joined the iNaturalist community. The pandemic put the brakes on some of the activities I had planned when I started, such as a plant phenology project with our local chapter of the North Carolina Native Plant Society and a BioBlitz at the AppState Nature Preserve in spring 2020. In addition to stay-at-home orders and lock-downs preventing access to some of my usual hiking spots, converting all our classes to remote teaching took its toll on spare time!

However, I still managed to break a few personal milestones. At some point over this past year, I reached 1,000 species observed. I meant to keep an eye on that number to see when it happened, but managed to miss that moment. One day I checked and I was already well over the mark, currently at 1,170. This is a moving target, of course, as IDs may change based on community input. I did manage to catch the exact time I broke the 5,000 observations threshold. Obs #5,000 is a life list first for me! When I started out, I imported a lot of stuff from my Flickr account. That certainly helped to get my observation numbers up quickly as many of these are actually from before I joined iNat. I still have a backlog of about a decade worth of photos to go through that I didn't post to Flickr so I'll be able to add additional pictures and some more past observations once I get the time for that. Somewhere along the way I managed to sneak into the spot of top observer for the Blue Ridge Parkway, although I guess that position depends on how competitive eraskin is going to get over it.

I'm grateful for the many people who have provided IDs for my observations! I've learned so much from this and discovered new species I didn't know existed because they were omitted from the field guides I have. When I started, I decided that I would try to pay back to the community by making at least as many IDs for others as I post observations. That turned out to be a lot of fun and I'm currently at about a 3:1 ratio of IDs vs. observations. I love digging through the unknowns for my area to see what I can recognize, and I also frequently go through Plantae for things I can narrow down to at least family if not genus or species. Just recently, I've discovered the need for IDs in Denmark and that looks like a lot of fun, too! Since I grew up in northern Germany, a lot of the plants are 'old friends' and have me on a trip down memory lane, being a child again picking wildflowers in the woods with grandma. This was well before I developed an interest in botany, but thankfully iNat knows most of the German common names for a lot of these as often that is the only name I know for them.

The forum is another great resource with oodles of tips and tricks. I used some of these to create the figures below to get an overview of all my observations and identifications on iNat so far. The link for the observation and identification heat maps was provided by bouteloua in a feature request, and the link to obtain your identifier stats can be found in the IdentiFriday thread. Note that the colors in the pie charts have no relation to the colors on the heat maps - I just happened to accidentally pick a very similar color scheme and didn't feel like doing them all over again. I guess the bottom line from this is that I really like to focus on the plants (~3/4 of my own observations, and >90% of my IDs for others).

iNat Observations

iNat IDs

Last but not least, a call-to-action! If you know something about plants and would like to help nudge some of those stuck at Plantae due to ID conflicts, here's a handy ID URL provided by arboretum_amy in yet another forum thread.

Posted on December 03, 2021 02:31 AM by annkatrinrose annkatrinrose | 1 observation | 0 comments | Leave a comment

White-flowered stonecrops of eastern North America

If you trust iNat's ID suggestions, then there's only one white-flowered stonecrop in the eastern US, Sedum ternatum. However, as anyone familiar with the pitfalls of computer suggestions might guess already, there are actually more than that. One in particular, Sedum glaucophyllum, is frequently misidentified as S. ternatum but tantalizingly close to having enough observations to be included in the next computer vision model. This post is intended to raise awareness of its existence and provide a comparison and guidance how to tell the two species apart.

I first encountered S. glaucophyllum on iNat while reviewing observations for S. ternatum and noticing different leaf arrangements than the plants I was familiar with. Almost at the same time, I was made aware of the existence of S. nevii through a plant give-away at the NC Native Plant Society. This made me look into these additional species a little bit more. Both have white flowers very similar to S. ternatum and neither of them are "known" by the current computer vision model.

Sedum Comparison
Botanical drawings of S. ternatum and S. nevii from Britton, N.L., and A. Brown, 1913, An illustrated flora of the northern United States, Canada and the British Possessions. Note the leaves in whorls of three on S. ternatum sterile shoots and opposite or whorled on flowering shoots as compared to leaves in spirals on sterile shoots of S. nevii with alternate leaf arrangement on the flowering shoots. S. glaucophyllum was split from S. nevii later and therefore did not have a separate drawing in this publication. However, it is similar in appearance but more variable and typically a little larger than S. nevii.

Both S. glaucophyllum and S. nevii are much rarer finds than the common woodland stonecrop and more specialized in their habitat. A glance at their distribution maps shows that both overlap with S. ternatum but are more restricted in their range and do no overlap with each other. S. glaucophyllum is endemic to Virginia and West Virginia with a few isolated occurrences in North Carolina and Maryland, while S. nevii is mostly found in Alabama with some populations in Tennessee and Georgia. S. glaucophyllum is found in cracks on cliffs and rocky habitats with moderately high pH soil and is absent in acidic rock outcrops. S. nevii grows in shallow, gravelly soils on steep bluffs of gneiss, an acidic, granite-like rock.

Sedum distribution map
Distribution of Sedum ternatum, S. glaucophyllum, and S. nevii in the Eastern US based on BONAP data to color in the distribution for each plant.

Since the current ranges of S. nevii and S. glaucophyllum do not overlap, location should be a clue for identifying these if found growing wild. (However, both species may be used as garden plants beyond their native range.) Digging a little deeper, it appears S. glaucophyllum differs from the other two species by chromosome count. While S. nevii always has 6 chromosome pairs and S. ternatum has 8, S. glaucophyllum shows 14 chromosomes or more, suggesting that it may have originated as an allopolyploid of the other two species.

It should be mentioned that there is one more species of white-flowered Sedum present in the eastern US, S. pusillum. However, this species is more similar to the elf orpine, Diamorpha smallii, currently included in the CV model and therefore more likely to be confused with that species than with S. ternatum. It is restricted to granite outcrops from Anson County, NC, to southwestern Georgia.

Posted on December 03, 2021 05:41 AM by annkatrinrose annkatrinrose | 3 comments | Leave a comment