Urticaceae (The Nettle Family)

Hairs of Stinging Nettle

                                                                                                         
I happen to be a big fan of some of nettles, enjoying them as a trailside nibble and as a way to sting the unwitting!  Crazy of me you might think, but unless you have allergies to it, varieties local to us really are nowhere near as devastating as the Heart-leafed nettle from Greene Deane's video below.  For an excellent introduction to some of the plant's characteristics, have a look:

Lucky for us, we won't run into these in Quebec, we're located just north of its range [1].  What we will run into, are Stinging (or Common) nettle, Dog nettle, Wood nettle, False nettle, Clearweed and Pennsylvania pellitory.  Only the first 3 of these have stinging hairs that can cause contact dermatitis, all except for Wood Nettle are associated with pollen allergies, and all except for False Nettle are edible, though in case you have a pollen allergy to the plant, you should sample only small quantities first to see how you handle it.

Alright!  With that said, lets have a look at them, one by one:

Stinging Nettle (Urtica dioica) 1

Leaves are spearhead-shaped, with stinging hairs on leaves and stem.  It likes growing in thick, tall colonies in fertile soil.

To collect (preferably young) leaves using your bare hand without getting stung, grasp the foliage firmly, not gently, and briskly roll it into a ball.  This will deactivate the stinging hairs and make it ready to eat.  Boiling the leaves also deactivates them, and some will argue it is a superior substitute to cooked spinach.  Save the boiled water though, as you've just made vitamin-rich nettle tea. 

Stinging Nettle 2

When Carl Linnaeus gave this species its name: "Dioica" (Latin borrowing from Greek 'di-oikia', or 'two houses'), he thought the plant was dioecious, which means that male and female reproductive organs don't appear together on the same individual.

But in this image, we see male and female flowers on the same plant, thus being monoecious (from the Greek "of one house").  This means that Stinging nettle, though most of the time it is dioecious, also has a monoecious form that appears in a population.











                                                                            


                                                                            
                                                                                            Dog Nettle (Urtica Urens) 1
Also known as dwarf nettle, this species does not reach the height of stinging nettle.  Its leaves are more oval shaped with deeper serration (teeth) than Urtica dioica's do.










                                                                                                               Urtica Urens 2

Here's the more mature plant, in flower along its stem.

The name Urtica urens is a repetition of the Latin root 'ur-' from the verb 'urere', which means 'to burn', referring to its sting.  It literally reads something like: the burning burning plant, haha.

When I was touring the excavations of Pompeii, I found this plant growing in abundance in the lawns that used to be floors of ancient houses.  Desperate for healthy greens (as we hadn't cooked our own meals the whole trip and were always just eating out), I would grab them, crush them and put them in my mouth! 





Wood Nettle (Laportea Canadensis) 1
Now we've left the Urtica genus, but are still in the Urticaceae family.  Comparing it to its cousins, Wood nettle has much broader leaves, but has similar looking flowers growing along the stem, (compare with picture: Stinging nettle 2).  It likes to grow in moist woodland soils, so look for it along streams or rivers.

It's just as edible as the other plants we've seen thus far, and it still stings! 





Wood Nettle 2

Note the asymmetrical arrangement of the Wood nettle leaves.  Unlike the Urtica species, it has an alternate leaf pattern, whereby the leaf stems of two leaves will never meet together at the same place on the main stem.  The Urtica species on the other hand, have an opposite leaf pattern. 

Compare the two leaf patterns (known as the phyllotaxis) in the following diagram, then come back to observe Wood nettle 2 (left) with alternate leaves.  Next, review back to Stinging nettle 2 and observe its opposite leaves.








Alternate vs. Opposite leaves

                                                                                                  
                                                                      False Nettle (Boehmeria cylindrica) 1

Left: Stinging Nettle,
Right: False Nettle (in flower)

Here are the stems of Stinging nettle and False nettle.  Looking at the right image, perhaps you'll notice and say "Hmmm I can`t really see any stinging hairs... maybe the image is too dark?"

Actually no, it`s not because it`s dark, false nettle is called false because it looks like stinging nettle, but lacks stinging hairs!

                                                                                                                      
                                                                                                              False Nettle 2
It's handy to have learned a bit about phyllotaxis from earlier, now we can see another helpful feature to note: an opposite leaf structure.  This, together with the plant's height, make it look a lot like stinging nettle.














Clearweed (Pilea pumila)
Here's a 1-2 minute segment with excellent closeups to this plant.

Note how the leaves have deeper ridges on the central vein and the 2 side veins.


I like how the video mentions that clearweed likes to grow in clusters and that they are wind pollinated, both characteristics being typical of the plants discussed so far.  But I started wondering, "well why does Dave in the video say it grows in clusters because it's wind pollinated?"  So I did a bit more research...  It readily self-sows by producing a very large number of seeds, and can spread slowly in fertile soil through its creeping rhizomes (root system).  These two traits are typical of the perennial nettle species, which includes all the species discussed so far.  So next time you see a patch of nettles, think: "Self-seeding + rhizomes = great strategy!".



                                                         Pennsylvania Pellitory (Parietaria Pensylvanica) 1 

Perhaps the family member most dissimilar to the others shown thus far, this is Pennsylvania Pellitory.  It likes partial shade, and can tolerate rocky soils, so it can be found growing along walls.  With long, thin toothless leaves, and a total absence of stinging hairs, what visual cue does it share in common with nettles? 






                                                                                                                      
                                                                                                 Pennsylvania Pellitory 2

Its fruit.  Growing along the stem where there used to be female flowers, these grow in clusters and are dispersed by wind.  This feature can be observed for all the species seen in this article. 

Before the fruiting stage, when it is still in flower, pellitory releases its pollen to be dispersed by wind, which causes severe allergic reactions to many people.  If you`re a sensitive individual, you can at least be glad to have identified the face of your nemesis (which reminds me of how I showed my dad last summer what ragweed, his summertime nemesis, looks like).  If you`re not sensitive though, you can enjoy this plant as a raw nibble or in salads!



Before concluding there are a few other plant species with the name nettle in them, so far I`ve come across `spurge nettle` and `horsenettle`.  These are not part of the family Urticaceae.

Recap:  
What's edible?  If you have no allergies to these plants, then everything except False nettle.
What's allergenic?  Pellitory pollen is a severe allergen, and the pollen of other nettle family members are mild allergens.
How do they spread?  All these plants depend on wind dispersed seeds and creeping rhizomes.
Do they all sting?  Clearweed, False Nettle and Pellitory lack stinging hairs.


For more reading online on the subject, I recommend Illinois Wildflowers, USDA plants profile and Pollen Library.  If videos are your fancy, Greene Deane and Dave Epstein are awesome sources for detailed information on a wide variety of plants!

The images included in this article are not my own, they can be found on Google by searching the individual plant names.

Happy nettle finding :)