Cinquefoils and False Strawberry

The other leaves in yesterday’s photo of great yellow woodsorrel belong to another five-petalled, yellow-flowering species, Potentilla canadensis (dwarf cinquefoil). This is a low-growing vine in the Rosaceae. It favors drier, rocky soils, like wild pinks and bluets do, and can be found growing near them in the Carderock area.

This is a good example of a rosaceous flower. The five distinct petals with the sepals peeping out between them are typical of the rose family. The leaf is atypical, being palmately compound with five lobes, but somehow it still looks characteristically rose-like to me, maybe because of the toothed margins.

Dwarf cinquefoil is found in much of the eastern US, especially from South Carolina to New Hampshire and the eastern parts of Ohio, Kentucky, and Tennessee.

Much more common and widespread is a near look-alike, Potentilla simplex, common cinquefoil. Note that the flowers are almost identical, and the leaves are very similar. To distinguish between the two species, consider these characteristics:

  P. canadensis P. simplex
vines generally short, hugging the ground generally long and sprawling
leaflets toothed more or less halfway along the margins toothed most of the way along the margins
middle leaflet much wider at the end (obovate) a little wider at the end (narrowly oval)
flowers generally start at the first node on the vine generally start at the second node on the vine

Another look-alike is in the same family but a different genus… for now. Recent research suggests that Duchesnea indica, false or mock strawberry, should be considered a Potentilla*. A very common lawn and garden weed, and a weed of natural areas as well, it produces fruit that isn’t edible. Well, technically it is edible- it’s not poisonous – but the strawberry-like fruits are flavorless.

These pictures show an obvious difference between the Potentillas and Duchesnea: the former have five leaflets (hence the common name cinquefoil), while the latter have three leaflets.


*Flora of the Southern and Mid-Atlantic States, Alan S. Weakley; p. 585

The Rose Family in Iceland, Part 2: Potentillas

Worldwide there are almost 1,700 species of Potentilla. More than 80 can be found in North America, four of which are in the Maryland Piedmont, including dwarf cinquefoil and common cinquefoil. There are five in Iceland.

 

Potentilla crantzii
alpine cinquefoil
Icelandic: gullmura

those fleshy leaves–>
belong to another plant;
the potentilla leaves are
pictured below:

Potentilla anserina
formerly Argentina anserina
silverweed
Icelandic: tágamura

 

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Providing stats for Potentillas is tricky, as there have been a lot of name changes recently. One of the older names for P. crantzii is Fragaria crantzii. The two genera are very closely related, so I’ve included this plant as well:

 

 

Fragaria vesca
strawberry
Icelandic: jarðarber

 

Yep, that’s good old strawberry (one of them, anyway). You can see a bit of the leaves on the lower right. The grassy looking stuff the flowers are poking through is horsetail (Equisetum species).

Back to silverweed: it can be found across the temperate regions of the northern hemisphere, and in most of North America except for the South and lower Midwest. It’s widespread in Iceland.

Alpine cinquefoil is limited in North America to northeastern Canada and Greenland. In Iceland it grows near rivers and the seashore.

What’s Green Now? Dwarf Cinquefoil

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Potentilla canadensis; Rosaceae

I can find no source to confirm that this plant is a true evergreen.  There are still-green leaves of it, but not many – and dwarf cinquefoil is everywhere.  So I have to conclude that there are some leaves that are protected enough to last.

Some authorities consider dwarf cinquefoil to be weedy.  It is very low-growing and prefers disturbed, low-nutrient soils, but does that make it a weed?  Not in my eyes.  Look for the charming rose-like flowers starting in late April.

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