Αρχεία Ημερολογίου για Νοέμβριος 2019

Νοέμβριος 10, 2019

Spring Beauties in North Carolina

The purpose of this page is to provide an identification aid for spring beauties (genus Claytonia) in the mountains of North Carolina. There are only two species native to North Carolina, Carolina Spring Beauty (Claytonia caroliniana) and Virginia Spring Beauty (Claytonia virginica), and their ranges overlap in the mountains.

C. caroliniana is common in rich cove and northern hardwood forests throughout the mountains and mostly found above 3,500 ft elevation, whereas C. virginica is more common in moist to rich forests in the eastern and central Piedmont. However, it can also be found in the mountain counties, usually below 3,500 ft elevation. In fact, both species may occur in very close proximity to each other, such as at New River State Park (~2,700 ft elevation) where C. virginica grows along the river trail and C. caroliniana along the adjacent forest trail.

When trying to distinguish between the two species based on morphology, it is diagnostic to get a good view of their leaves. Their flowers look pretty much identical, but they can be easily distinguished by the shape of their leaves. C. caroliniana has a broader leaf blade clearly differentiated from a petiole attaching it to the stem, whereas C. virginica has slender, grass-like leaves without a clearly differentiated petiole.


The NC range map above was colored in using data from the Vascular Plants of North Carolina website. The plant drawings are from the USDA PLANTS database and not copyrighted (original source: Britton & Brown: An illustrated flora of the northern United States, published 1913). For another comparison of the leaves of the two species, also see the Native Plants of the Carolinas and Georgia website.

Posted on Νοέμβριος 10, 2019 1242 ΠΜ by annkatrinrose annkatrinrose | 4σχόλια | Αφήστε ένα σχόλιο

Hepaticas in North Carolina

The purpose of this page is to provide an identification aid for liverleaf (genus Hepatica) in the mountains of North Carolina. There are two species/varieties (depending on source) native to North Carolina, Sharp-lobed Liverleaf (Hepatica acutiloba, syn. Hepatica nobilis var. acuta) and Round-lobed Liverleaf (Hepatica americana, syn. Hepatica nobilis var. obtusa), and their ranges overlap in the mountains and western Piedmont.

H. acutiloba is common in rich cove and northern hardwood forests in the mountains and rare in the higher elevations of the western Piedmont, whereas H. americana is common in moist to rich forests in the Piedmont and rare in the lower elevations of the mountains. Based on their reported ranges shown in green in the USDA PLANTS database maps below, it is probably safe to assume that any Hepatica observed in the State Parks around the High Country of northwest North Carolina is H. acutiloba.

When trying to distinguish between the two species based on morphology, it is diagnostic to get a good view of their leaves. H. acutiloba has rhombic leaves with parallel sides tapering to an acute tip, whereas H. americana has strongly rounded leaves with convex sides. In the absence of leaves, some features of the flowers may aid in identification as well. The flowers are subtended by three bracts, which in H. acutiloba have acute tips and often show between the sepals when the flower is viewed from above, whereas they are rounded and seldom show in H. americana. H. acutiloba is more likely to have white flowers with more than 6 sepals, while these occur more rarely in H. americana.


The NC range map above was colored in using data from the Vascular Plants of North Carolina website. The plant drawings are from the USDA PLANTS database and not copyrighted (original source: Britton & Brown: An illustrated flora of the northern United States, published 1913). For more pictures comparing these two species, also see the Native Plants of the Carolinas and Georgia website.

Posted on Νοέμβριος 10, 2019 0123 ΠΜ by annkatrinrose annkatrinrose | 1 σχόλιο | Αφήστε ένα σχόλιο

Clethras in North Carolina

There are two species of Clethra (summersweet or sweet pepperbush) native to North Carolina that are often confused and this page is supposed to provide some guidance on identification. Their ranges actually do not overlap, so for plants found growing wild, it is safe to assume that any Clethra found growing in the mountains (or more rarely in the foothills) is C. acuminata, whereas any Clethra found in the coastal plain (or more rarely in the Piedmont) is C. alnifolia. (For plants in cultivation, this neat separation of course doesn't hold true. Most plants found in public plantings and gardens are cultivars of C. alnifolia.)

Growth habit, leaves, and bark can be diagnostic when trying to distinguish between the two species based on morphology. C. acuminata is a large shrub to small tree 10-12 ft big on average, whereas C. alnifolia is a thicket-forming shrub usually no taller than 6 ft. Older stems of C. acuminata have reddish and peeling bark ('cinnamon bark' giving it one of its common names, cinnamon clethra), wheres the stems of C. alnifolia are brown-gray with thin and smooth bark. The leaf shapes are what give these plants their scientific names. C. acuminata has pointed leaves with concave sides along the tip (acuminate) and finely toothed margins, whereas C. alnifolia leaves resemble alder (Alnus) leaves and are blunt or pointed with straight sides and serrated margins that do not extent all the way to the base. If the plants are in bloom, it is possible to use flower scent as an indicator as well. C. alnifolia has a sweet fragrance that is hard to miss (hence its common name summersweet), while C. acuminata has a more spicy fragrance that is barely noticeable.

The NC range map above was colored in using data from the Vascular Plants of North Carolina website. The plant drawings are from the USDA PLANTS database and not copyrighted (original source: Britton & Brown: An illustrated flora of the northern United States, published 1913). They are scaled to each other - C. acuminata has indeed larger leaves compared to C. alnifolia. For another comparison of the leaves of the different Clethras and similar species, also see the Native Plants of the Carolinas and Georgia website. (C. tomentosa listed on that page is now mostly treated as a variety or synonym of C. alnifolia and not a separate species.)

Posted on Νοέμβριος 10, 2019 0525 ΜΜ by annkatrinrose annkatrinrose | 0σχόλια | Αφήστε ένα σχόλιο

Νοέμβριος 13, 2019

Trout Lilies in North Carolina

The purpose of this page is to provide an identification aid for trout lilies (genus Erythronium) in North Carolina. This is a fun one! Misidentifications run rampant in this genus - guilty of it myself - due to a fairly recent split into two species that doesn't seem to have trickled down yet into popular field guides. It takes a closer look at certain plant features according to more recent botanical manuals to sort them out.

The two species in question are E. americanum (the "original" trout lily) and E. umbilicatum (dimpled trout lily), which was split out and described as a separate species in 1963. Both have yellow flowers and mottled leaves. It turns out that E. umbilicatum actually is the more common one in the state, but this fact is nearly impossible to discern from field guides targeting the lay person. Out of a dozen pictorial wildflower guides for NC or the surrounding area on my book shelf, more than half only list E. americanum and make no mention of E. umbilicatum. Three provide prominent treatment and a picture for E. americanum and do acknowledge that another species exists, but seemingly as an afterthought. Only one book gives E. umbilicatum the more in-depth discussion but happens to get the identification features mixed up, erroneously stating that this species has auricles on the tepals, which actually is a distinguishing characteristic of E. americanum. None of the books have pictures of both species showing distinguishing features. In conclusion, popular field guides are of no help in this matter and will lead to misidentifications of E. umbilicatum as E. americanum.

Even herbarium data has to be taken with a grain of salt as many old specimens identified as E. americanum may in fact represent records of E. umbilicatum. The curators of the range maps caution about this and tried to account for it by considering only recent records and those that have been reexamined and confirmed, but there may still be some errors and an underrepresentation of actual occurrences in the maps. Both BONAP and SERNEC data suggest that E. umbilicatum is the more wide-spread species in NC. E. umbilicatum is common in the mountains and southwestern Piedmont, while E. americanum occurs less frequently in the Piedmont and is rare in the mountains.


(Map data from BONAP, top, and Vascular Plants of North Carolina, bottom.)

The first clue to species identity in this case may be habitat type. E. americanum is described as a species of basic mesic forests and rich bottomlands, limited to very rich, high pH soils. This rules out most habitats in the mountains and Piedmont, which tend to have low pH acidic soils. E. umbilicatum is not as picky about soil pH and grows in a wide range of forest types, including those acidic soils typical for the Southern Appalachians.

The best way to identify to species level based on morphology when in bloom is to look for auricles ("ears") on the innermost tepals. Other characteristics like the color of the pollen or tepals are apparently not reliable diagnostic features due to their high variability. Only E. americanum has these auricles while E. umbilicatum does not. The picture below shows what to look for (highlighted by the circles in the enlarged picture).

(Image source: Wikimedia, public domain; see Flickr for another great picture showing the auricles)

However, the best stage to distinguish the two species is when they are fruiting. E. umbilicatum is named for its umbilicate capsule, meaning it has a dimple in the top resembling a belly button. The capsules of E. americanum have rounded or pointed tips instead. (For a side-by-side comparison, check out the capsule pictures on Carolina Nature). The stalk that is holding the capsule is weak and flops over, causing it to rest on the ground in E. umbilicatum, while it is able to stand upright and hold the capsule "arching gracefully like a swan" as I've seen it described in one account for E. americanum.

(Image source: Wikimedia, shared by user Doppelbrau with a CC BY-SA 4.0 license)

E. umbilicatum is further divided into subspecies based on the presence or absence of stolons.

Posted on Νοέμβριος 13, 2019 0202 ΜΜ by annkatrinrose annkatrinrose | 7σχόλια | Αφήστε ένα σχόλιο

Νοέμβριος 24, 2019

Chickweeds in North Carolina

The purpose of this page is to provide an identification aid for chickweeds in North Carolina, predominantly the type found blooming in the woods in the mountains in spring. There are two genera commonly referred to as chickweeds: Stellaria and Cerastium. Here in NC, we have three native members of Stellaria (S. pubera, S. corei, and S. alsine) and two native members of Cerastium (C. nutans and C. brachypodum), with non-native and invasive species from both genera also present. This sounds like a mess to sort out, but if the goal is to identify native Stellaria it is actually fairly easy to tell these apart from the others. By far the most common one found in the woods in the mountains is the star chickweed, S. pubera.

The first step would be to distinguish native from non-native species, and Stellaria from Cerastium. If the plants are in bloom, the size of the flowers and shape of the petals is the best indicator, with different leaf shapes to support identification. As shown on the figure below, S. pubera has flowers twice the size of the others (1/2 inch across, compared to 1/4 inch) and is also known by the common name giant chickweed because of this. The characteristic that sets Stellaria apart from Cerastium is the depth of the notches on the petals. All these plants have five petals, but in Stellaria they are notched so deeply that they often appear as ten, whereas the notches don't go as far in Cerastium.


Comparison of flower size and characteristics of common native chickweed (left) and three common invasive chickweeds (right), colored in with Photoshop to make it easier to distinguish sepals and petals. The original flower pictures are from the illustrated flora by Britton & Brown, published in 1913 (now public domain), and were downloaded from the USDA PLANTS database.

A large-flowered plant found growing in the woods is most likely S. pubera. However, S. corei also occurs throughout the mountains and has similarly large flowers. The way to tell between S. pubera and S. corei when in bloom is by the length of the sepals. In S. pubera they are shorter than the petals, while in S. corei they are longer and extend past the petals when the flower is fully open. The pictures below illustrate this characteristic. Note these are young flowers that have just opened up, so the anthers are bright red. As the flowers mature, they might lose the bright color. The anthers on S. pubera stay dark, often an orange-brown, while I've seen some flowers of S. corei where the anthers were lost or not as strikingly colored.


Comparison of the two chickweeds native to NC mountain forests: The one on the left is the common star chickweed (Stellaria pubera) and was a rescue from a construction site; the one on the right is the rare Tennessee chickweed (Stellaria corei) purchased from a native plant nursery.

As mentioned above, the ranges of these two chickweeds overlap, with S. pubera common throughout the mountains and Piedmont, while S. corei is rare and restricted to the mountains and maybe upper Piedmont. Both species prefer rich forest habitats, while the third native Stellaria species, bog chickweed (S. alsine), is a wetland specialist and only occurs in the southwestern part of the state.


The maps were colored in using data from Vascular Plants of North Carolina for the native species and BONAP for the non-native ones. The plant drawings are from the USDA website and not copyrighted (original source: Britton & Brown: An illustrated flora of the northern United States, published 1913). They are scaled to each other for size comparison.

There are several non-native species in this genus and only the two most common ones are shown in the figure above. (The others are less common and more scattered.) Common chickweed, S. media, appears to occur throughout the state, with gaps in the occurrence data probably due to underreporting rather than an actual absence in those counties. Grass-leaved chickweed, S. gramineum, is also wide-spread. Besides differences in the flower size and their propensity to grow in human-disturbed areas, the shape of the leaves is another way to tell the invasives from the natives. S. media has more heart-shaped leaves, and S. graminea has more grass-like leaves compared to the natives.

No discussion of chickweed would be complete without at least mentioning the second genus, Cerastium, commonly referred to by the name chickweed. As explained above, these can be distinguished from Stellaria by the less deeply notched petals. The most common native species to encounter from this genus is nodding chickweed, C. nutans, which is fairly common in rich woods in the mountains and rare in the Piedmont. The second native species, S. brachypodum, has only few reports in the state so far and may have actually been introduced.


The maps were colored in using data from Vascular Plants of North Carolina for the native species and BONAP for the non-native ones. The plant drawings are from the USDA website and not copyrighted (original source: Britton & Brown: An illustrated flora of the northern United States, published 1913). They are scaled to each other for size comparison.

There are at least five non-native Cerastium species in the state and only the two most common ones are shown in the figures above. These are invasives of disturbed areas and distributed throughout the state. Gaps in the occurrence data are probably due to underreporting rather than an actual absence in those counties. Other non-native species are less common and more scattered throughout the state. All of these would mostly occur in human-disturbed areas, such as roadsides or as garden weeds. Sticky chickweed (C. glomeratum) is an annual weed covered in sticky hairs and with sepals extending beyond the petals, whereas mouse-ear chickweed (C. fontanum) is a mat-forming perennial with stolons that root where they rest on the ground and has sepals shorter than its petals.

Posted on Νοέμβριος 24, 2019 0658 ΜΜ by annkatrinrose annkatrinrose | 2σχόλια | Αφήστε ένα σχόλιο