Hints for identifying Carex using photos.

This blog started as a response on this website to an observation. However, I'm glad I copied and pasted the text into a document prior to posting. The software wiped out my note at "too long" and exceeding the 1000 character limit (it has more than 5000). So, I'll try posting it here.

As for Carex photos, photos of just the flowers (spikelets) are certainly helpful and often diagnostic. The insect is also interesting but would be a separate observation. It is hard to say exactly what works best with sedges, but here are a few general rules of thumb.

(1) Roots may be required. I used to identify Carex frankii throughout Arkansas. However, the closely related C. aureolensis has very long rhizomes. So, without a photo of rhizomes I can't tell you which is which. Someone might, but I can't as I've not studied other characteristics or researched it. Similarly, if memory serves me well, C. floridana has long rhizomes and C. nigromarginata forms large circular clones. Varieties of C. albicans may also require looking for rhizomes. Some taxa such as C. hyalinolepis have large and distinctive rhizomes. So, when I collect, I try to get rhizomes or roots of any Carex. The same would apply to photos in general.

(2) In the next two months from Louisiana north with climate, look for very short stalked carices such as C. umbellata, C. tonsa, C. reznicekii, and others. I love the C. umbellata story in Arkansas as an example. The state had listed it as S1 (six or fewer sites or subject to other hazards of extirpation). I started collecting Carex in 1990 and for a few years walked over it every year. Why? These look like a circular clump of grass all year long. When I did discover it, I started finding it everywhere. A few weeks later, I added six county records in about ten minutes of field time outside my car! The perigynia are on very short stalks, 1-3 cm tall. They bloom early, late Feb. to March in Arkansas. L. L. Gaddy found ants like the oil bodies (eliasomes?) at the base of the perigynia (same is true for C. nigromarginata) and I'd often find plants covered with ants. By April, the plants would be sterile and by the end no sign of perigynia were left. But botanists don't hunt them in March! In the east (NC, GA, et al.) there's C. tonsa which tends to be found in tiny clumps with a few culms less than 2 inches high on disturbed muddy edges of gravel parking lots, which I might call its preferred habitat! Trails also work. It seems to like disturbance. For identification, some species will require careful and clear photos of the length of the culms and peduncles.

(3) Leaf sheaths are often important and without a clear view of sheathless or sheathed species, a person gets stuck in the keys. Leaf width is important in some species, so taking a photo with a millimeter ruler would help with that and many other characteristics.

(4) The leaves themselves can be important. Several species have distinctive glaucous leaves or hairy leaves. For example, C. oxylepis var. oxylepis is (more or less?) glabrous while var. pubescens is quite hairy. Hairs may not be easy to see or even photograph. On rare occasions, I found hairs on supposedly glabrous plants only to be told "Ignore the sparse hairs at the base of the stem."

(5) Spikelet length and shape is often important. You had great photos for that.

(6) Perigynia and achenes are often important at the species level. To be honest, if I was going to regularly photograph sedges, I'd have to come up with a good method. A scope with a camera would of course be ideal, but as you will see below, I've always had other ideas.

Conclusions:

Despite being a regional ecologist for the US Forest Service before I retired and collecting thousands of Arkansas Carex specimens, I've always considered myself someone of a naturalist more than a scientist. That is, I don't conduct my laboratory or even field research. I like to find things and let others deal with the specifics. I've always wanted to be like my professor, Dr. Douglas James at the U of Arkansas, who seemed to be able to pick up anything and give it a name. I took the same approach to Carex. So, you will see me taking photos of sedges out of season without fruit or some diagnostic characters shown. Here's a recent example: https://www.inaturalist.org/observations/20071014. Based on field experience, I feel 99.9% sure of this ID despite the sterile plant! When I look at a sedge in the Section Ovales, I still want to be able to identify it on sight without using a scope. Most people fear any attempt to identify them accurately. However, I found some very easy to determine. C. longii has a particular look to it that is hard to define (and a unique perigynium shape). C. festucacea also has a hard to define look to it. C. ozarkana is very easy to identify on sight, but can be confused with C. festucacea at first. C. molesta (upland wet spots) and C. molestiformis (riverine wet spots) have slightly overlapping habitats (such as upland wet spots near rivers!) but it really takes looking at the achenes to easily nail the ID (which is done very easily). These latter two I studied in about 1992 or 1993 by making about 25 collections in Baxter County. If I recall correctly, Tony (A. A.) Reznicek agreed with all my IDs. Then, I compared the collection sites and defined the habitats!

So, have fun! Otherwise, it is like work!

Publicado por sedgehead sedgehead, 12 de febrero de 2019

Observaciones

Fotos / Sonidos

Observ.

sedgehead

Fecha

Octubre 4, 2018 04:48 PM CDT

Descripción

Common in upland woodlands in the Ozarks and most of Arkansas. This late summer specimens show the seasonal look of this species. This ID is not firm as this could also be Carex reznicekii, but I have not field confirmed the difference in the two. A second photos shows the general woodland habitat where this was growing (but the second photo was not taken at this site).

Fotos / Sonidos

Observ.

sedgehead

Fecha

Octubre 25, 2018 01:59 PM CDT

Descripción

Common in glades and rocky bluffs with seepy water sometimes. This was not blooming but having collected thousands of Carex specimens in Arkansas I'm very comfortable with this ID. I saw two colonies here, this and a much larger one nearby covering hundreds of square feet.

Fotos / Sonidos

Square

Observ.

sedgehead

Fecha

Octubre 24, 2018 02:53 PM CDT

Descripción

I'm not positive. This could be S. triglomerata, but S. oligantha is much more common here.

Fotos / Sonidos

Square

Observ.

sedgehead

Fecha

Octubre 24, 2018 03:14 PM CDT

Descripción

I need to compare leave width with C. nigromarginata and C. albicans and even C. reznicekii formally. I feel sure this is C. umbellata.

Fotos / Sonidos

Observ.

sedgehead

Fecha

Enero 24, 2019 02:49 PM CST

Descripción

Common on limestone glades in county and at other sites at bluffs and waterfalls; several colonies found in this area.

Fotos / Sonidos

Observ.

sedgehead

Fecha

Enero 24, 2019 02:51 PM CST

Descripción

Common on limestone glades in county and at other sites at bluffs and waterfalls; several colonies found in this area.

Fotos / Sonidos

Observ.

sedgehead

Fecha

Enero 24, 2019 02:39 PM CST

Descripción

Common on limestone glades in county and at other sites at bluffs and waterfalls; several colonies found in this area.

Fotos / Sonidos

Observ.

sedgehead

Fecha

Enero 24, 2019 02:47 PM CST

Descripción

Common on limestone glades in county and at other sites at bluffs and waterfalls; several colonies found in this area.

Fotos / Sonidos

Observ.

sedgehead

Fecha

Enero 24, 2019 03:41 PM CST

Descripción

Common on limestone glades in county and at other sites at bluffs and waterfalls; several colonies found in this area.

Fotos / Sonidos

Observ.

sedgehead

Fecha

Enero 24, 2019 03:38 PM CST

Descripción

Common on limestone glades in county and at other sites at bluffs and waterfalls; several colonies found in this area.

Fotos / Sonidos

Observ.

sedgehead

Fecha

Enero 22, 2019 11:17 AM CST

Descripción

Common on glades in county.

Fotos / Sonidos

Observ.

sedgehead

Fecha

Febrero 1, 2019 03:41 PM CST

Descripción

This species is locally numerous on rocky glades and moist to temporarily dry cliffs where rocks bring water to the surface when it rains. The first photo shows nearby slopes but has not plants.

Fotos / Sonidos

Observ.

sedgehead

Fecha

Febrero 3, 2019 09:39 AM CST

Descripción

I don't think this is the closely related and recently described Carex reznicekii based on mostly hardwood habitat. This species was listed as rare in Arkansas in the 1990s (known from six or fewer sites and classified as S1), but I found it in about 2/3 of Arkansas counties. It should start blooming soon but finishes blooming in April. It is very easy to overlook because the perigynia are hidden near ground level in the leaves. This plant was growing in a bare spot in an old logging road.

Comentarios

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If you have troubles with identifying Carex you might post your plants on a facebook group: https://www.facebook.com/groups/478674815938899/

Publicado por optilete hace más de 1 año (Marca)
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Many thanks! However, I bailed out of Facebook for the third and final time last year. I found it too intrusive. Others might find the link useful so thanks!

Publicado por sedgehead hace más de 1 año (Marca)

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