I spent a lot of time last week out and about, photographing flowers. Normally I’d spend more time writing meaningful comment to post, but time is in short supply just now, so for the next few days I’m just going to post pretty pictures of spring ephemerals.
…and white (Erythronium albidum).
Forest floors in the Maryland piedmont are carpeted now in spring ephemerals. Spring beauties are everywhere, Virginia bluebells and Dutchman’s breeches seem to be confined to wetter areas, and in drier areas, you’ll see toothworts.
Formerly placed in the genus Dentaria, toothworts are now lumped with the bittercresses in the genus Cardamine. The flowers are similar on close inspection but the overall difference in appearance between toothwort and bittercress plants is pretty obvious.
Older guidebooks frequently list two to five species of toothworts in the eastern US. Here’s a quick look at the names (it’s not my intent to provide a complete synonymy):
|current name||older name(s)||common name(s)|
|Cardamine angustata||Dentaria heterophylla||slender toothwort|
broad-leaved toothwort crinkleroot
|Cardamine maxima||Dentaria maxima||large toothwort|
C. dissecta has a limited range, from Alabama northeast into West Virginia, and is endangered in Indiana. C. maxima seems to have disjunct populations in Kentucky, Wisconsin, Michigan, Pennsylvania, and a few parts of New England; it’s threatened in Michigan, endangered in New Jersey, and possibly extirpated in Maine. Neither of these species has been reported in Maryland.
C. diphylla is found in the Appalachian South, the mid-Atlantic, New England, and upper midwest, possibly with a few occurrences farther west, from Arkansas to Minnesota. MBP has only a few records in the piedmont, and a few more in the Appalachian Plateau. One of the records is of a sample in the Norton-Brown Herbarium; it was collected in 1974 “[o]ff beltway exit to Great Falls near Seno [sic] Canal”, which is right along the Potomac gorge and my usual hunting grounds. Maybe I have a new quarry to track?
C. concatenata is found mostly in the mid-Atlantic and mid-west and New England, though it does range into the South and the eastern Great Plains. It’s endangered in Maine and New Hampshire. It seems to be in most of Maryland except the far west and southern Eastern Shore.
The flowers of all of these toothworts are very similar in size, shape, and color, and can’t easily be used to distinguish between the species. It’s best to look at the leaves.
C. concatenata has no basal leaves present at blooming; on the stem is a single whorl of three leaves, each leaf palmately divided, with serrated leaflets. It’s worth noting that there seems to be a wide range of morphological variation: on some plants the leaflets are quite narrow, while on others they’re rather broad; on some plants there are three leaves in a whorl, but on other plants they might be sub-opposite, or there might be only two leaves.
Be that as it may, C. angustata is pretty easy to distinguish from C. concatenata. It has two alternate or sub-opposite stem leaves, each with three leaflets (usually) that are quite narrow and serrated to some degree. The basal leaf (sometimes leaves) is large, with very broad leaflets, on a very long petiole.
Another species worth mentioning is Cardamine bulbosa, commonly called bulbous bittercress or toothwort. Although it was never a Dentaria and is more often referred to as a bittercress than a toothwort, the flowers look toothwort-y. The species is found in most of the eastern US (and most of Maryland), but not in Maine, and it’s endangered in New Hampshire.
At this time of year many plants are putting out – or have already have put out – heart-shaped leaves that stay close to the ground. Like the violets in my last post, for example. Or like these, which belong to wild ginger (Asarum canadense). —>
I was thinking recently about two other species with similar cordate basal leaves. When young, they are easily confused with each other, at least at first glance. Luckily, I was able to find both growing right next to each other!
<—At bottom center in this photo is a particularly despised alien invasive called garlic mustard (Alliaria petiolata). Surrounding it is a much-loved native called golden ragwort (Packera aurea, formerly Senecio aureus). Here’s a little primer on how to tell them apart.
These are leaves of golden ragwort. —>
This one belongs to garlic mustard. –>
The leaf edges are clearly scalloped rather than toothed. The leaf venation is also pinnate, but also netted, giving the leaf a bit of a crinkled appearance.
<— This is a stem leaf of golden ragwort. Look at how different it is from the stem leaves of garlic mustard [below], which look similar to the basal leaves. Also in this photo you can see the flower buds at top.
Here are buds of golden ragwort. By the time the plants reach this stage, they are easy to tell apart.
Garlic mustard is in the Brassicaceae, a family which also includes several of our native spring ephemerals, like the toothworts and rockcresses. Golden ragwort is in the Asteraceae, and is by far the earliest blooming native of that family (in this region, anyway).
Since violets (Viola species) hybridize so readily, they can be tricky to identify. Individual plants sometimes show characteristics intermediate between two species. Take a look at the USDA PLANTS Database page for Viola and you’ll see what I mean: of the 129 species shown there, 43 are hybrids. (Presumably these are naturally occurring hybrids, not cultivated varieties.)
Yellow violets are easier, because there are only a species, and only three of those are found in Maryland. Right now, one of them is blooming in the Potomac gorge area: smooth yellow violet (Viola pubescens var. scabriuscula, formerly known as Viola pensylvanica). There’s a second variety of the same species that’s commonly called downy yellow violet (V. pubescens var. pubescens).
I started writing this post almost a year ago, then realized I didn’t have any good photos for it, so set it aside until now. Over the last few days I’ve examined a few dozen yellow violets, and they’ve all been the smooth variety. I hoped to have photos of both for this post, but if I wait too long I’ll have to set it aside again, so here goes.
The two varieties bloom at about the same time (April) and grow in the same habitat (moist deciduous woodlands). The main difference between the two is hinted at in the name: in botany, pubescent means covered in short hair, while scabriuscula means slightly rough.
Although this one is smooth yellow violet, you can see some pubescence on the leaf base and adjoining stem on the lower right leaf. Smooth yellow violet can have a slight pubescence but is mostly glabrous (smooth), which you can see on the rest of this plant.
Another identifying characteristic is the shape of the stipules. Those of downy yellow violet are broadly oval, with a blunt tip, while those of smooth yellow violet are narrowly oval, with a pointed tip, as shown here. (A stipule is a small, leaf-like bit of tissue found where the petiole meets the main stem; there’s one in the very center of this photo.)
Finally, look at the whole plant: downy yellow has a single flowering stem, with one basal leaf or none, while smooth yellow has two or more flowering stems and one to three basal leaves.* The plant pictured here appears to have three basal leaves (at one o’clock, six o’clock, and eleven o’clock), one flowering stem with a blossom and a bud (seven o’clock), and a second flowering stem still developing (twelve o-clock).
I’ll keep looking at yellow violets this spring, and if I find any of the the downy variety I’ll write a follow-up post.
*descriptions from the Flora Novae Angliae by way of the New England Wildflower Society’s gobotany website (which every botanerd should bookmark):
1a. Stems solitary, with 0 or 1 basal leaves; leaf blades densely pubescent; stipules broad-ovate, with an obtuse apex … 21a. V. pubescens var. pubescens
1b. Stems 2 or more from the apex of the rhizome, with 1–3 basal leaves; leaf blades glabrous or sparsely pubescent; stipules lanceolate to narrow-ovate, with an acute apex [Fig. 935] … 21b. V. pubescens var. scabriuscula Torr. & Gray
And here are a few more early spring bloomers to watch for in the Potomac Gorge.
Not as common as some of the flowers in yesterday’s post, but still easily found in rocky areas, are early saxifrage (Micranthes virginiensis, formerly Saxifraga virginiensis), which are the white flowers on the right in this photo, and smooth rockcress (Boechera laevigata, formerly Arabis laevigata), which is the plant in bud on the left.
Growing right on top of boulders, the incomparably wispy and delicate lyre-leaved rockcress (Arabidopsis lyrata, formerly Arabis lyrata) are in full bloom already, but they have a long bloom period.
Also growing right on rocks, though in more open, sunny areas, is moss phlox (Phlox subulata). It, too, has a long bloom period.
Don’t forget to look up! Spicebush (Lindera benzoin) is in full bloom.
Another yellow-flowering woody plant is leatherwood (Dirca palustris), but it’s uncommon. If you find a stand please post a comment!