Quick Carderock Update

I had a quick look around the Carderock area on Friday (March 29), and saw the following plants blooming or budding. Also had fun taking closeup shots.

Arabidopsis lyrata (lyre-leaved rockcress): a few flowers  –>

 

Boechera laevigata (smooth rockcress): buds
Cardamine angustifolia (slender toothwort): buds

<–Cardamine concatenata (cut-leaf toothwort): flowers

Claytonia virginica (spring beauty): lots of flowers
Dicentra cucullaria (Dutchman’s breeches): a lot of buds, a few flowers

 

 

Dirca palustris (leatherwood): full bloom –>

 

 

 

<–Erythronium americanum (trout lily): gobs of leaves; 5 flowers

Lindera benzoin (spicebush): flowers

 

 

 

Mertensia virginica (Virginia bluebells): lots of buds, just a few open flowers    –>

 

 

 

<–Micranthes virginiensis (early saxifrage): full bloom

The next few weeks should be spectacular.

Late March

Things are still moving along slowly in the Potomac Gorge, but with warmer weather coming I expect the show will really get going soon.

On March 25 I found large patches of harbinger-of-spring blooming near Billy Goat B.

 

The bluebell buds should open in the next few days.

 

 

 

 

A few cutleaf toothwort are out, and lots of spring beauties, of course. Spicebush is also starting to bloom.

 

 

 

And there were several bloodroots flowering near Old Angler’s.

See LW’s comments on the last post for an update of the area around Carderock.

Spring Cress

Thanks to LW’s comment on my recent post about toothworts, I was finally able to see a good-sized stand of Cardamine bulbosa, also known as spring cress, bulbous bittercress, or bulbous toothwort.

This species is a wetland obligate; here you can see it almost standing in the water of a vernal pond.

 

The cauline (stem) leaves are entirely different from the slender and cut-leaved toothworts’.

 

 

The basal leaves are, too.

 

 

 

The flowers and inflorescence look much like the toothworts, though. Another Cardamine species found in Maryland, limestone bittercress (C. douglassii), is almost identical to spring cress, but it species has hairy, dark purple sepals rather than the smooth, green sepals seen here.

 

Spring cress is native to the eastern US, where it ranges from Florida to New Hampshire (where it’s endangered) and into the Great Plains from Texas to Minnesota.

Toothworts

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

Cardamine concatenata

Dentaria laciniata
Dentaria concatenata
cut-leaf toothwort

Cardamine diphylla

Dentaria diphylla toothwort
broad-leaved toothwort crinkleroot

Cardamine dissecta

Dentaria dissecta
Dentaria multifida
fine-leaved toothwort
dissected toothwort
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. angustata is a southeastern species, ranging from south-central Alabama north to central Indiana and northeast into Pennsylvania. In Maryland it seems to be found mostly in the piedmont.

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 spring cress or bulbous 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.

Compressed (part 2)

Here are some of the showier spring ephemerals to watch for in the Potomac Gorge this week.

In the floodplain close to the river, Virginia bluebells (Mertensia virginica; left) are approaching peak bloom. Mixed in with them in a few places are Dutchman’s breeches (Dicentra cucullaria; below right), which you might also find on moist, rocky outcroppings.

Trout lilies (Erythronium americanum; above left) like moist soils, too. Generally I see them in the transition areas between floodplain and slopes.

Further upslope are cut-leaf toothworts (Cardamine concatenata; left).

 

On drier slopes watch for scattered patches of bloodroot (Sanguinaria canadensis; below).

 

 

Look for twinleaf (Jeffersonia diphylla; below) in moist, rocky areas. They like limestone soils, so aren’t as widespread as these other species, but where they do grow they they tend to grow en masse.

Spring beauties (Claytonia virginica; below) are just about everywhere.

 

 

 

 

More tomorrow.

But First, a Quick Update

I went scouting on the Billy Goat C Trail Monday. Harbinger -of-spring is still blooming. More spring beauties are blooming.

Just a few Dutchman’s breeches are open.

 

 

 

 

As are cut-leaf toothwort.

 

 

 

 

And just a few golden ragwort.

 

 

 

 

Virginia bluebells are budding up nicely. A few more days of warm weather and the ephemerals show will be underway.

On the Last Day of Winter

Today is the first day of meteorological spring* (astronomical spring is still three weeks away), but as of yesterday, the 28th of February, the wildflower show had already begun along the Potomac. Barely.

Claytonia virginica (spring beauty; Montiaceae)

Just a few dozen of these were up in sheltered locations.

This one specimen of Packera aurea (golden ragwort; Asteraceae) already had well-developed buds. Often this species will retain leaves through the winter, and many low-lying leaves were visible, but I saw none of the tall growth yet. In the same location last year just a few flowers were open on March 23, with peak bloom about April 13; in 2015, I saw the first ones March 24, with peak bloom in mid-April.

Erigenia bulbosa (harbinger-of-spring; Apiaceae)

More about this in an upcoming post. Can you see it sheltering there under the maple leaf? That’s one plant with about 14 flowers!

A few alien species are starting to bloom: Veronica hederifolia (ivy-leaved speedwell) and Cardamine hirsuta (hairy bittercress).

And, I saw one clump of Mertensia virginica (Virginia bluebells) foliage emerging, but that makes a boring photo.

*more on meteorological seasons from NOAA