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Early Spring Aliens

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At the end of February, technically still wintertime, I saw this carpet of white on the Cabin John Trail. It wasn’t spring beauties, and it wasn’t leftover snow, either.

This is Galanthus nivalis (snowdrops; Amaryllidaceae), a perennial native to Europe. It naturalizes well, meaning you can plant a few dozen bulbs and enjoy the show year after year as they spread through your garden. Unfortunately, it naturalizes a little too well, and so can be found in woodlands throughout the mid-Atlantic, as well as some other parts of the country.  The National Park Service doesn’t list the species in its manual Plant Invaders of Mid-Atlantic Natural Areas, but the University of Maryland Cooperative Extension considers it invasive.

What exactly does it mean to be “invasive”? I like the USDA Forest Service definition:

An “invasive species” is defined as a species that is

  1. Non-native (or alien) to the ecosystem under consideration; and,
    2. Whose introduction causes or is likely to cause economic or environmental harm or harm to human health.

Whether or not snowdrops cause environmental harm may be just a matter of degree, or time.

I didn’t know that snowdrops were a problem before researching them for this post. Now there’s another item on my garden to-do list: pull out the snowdrops.

When it comes to Vinca minor (periwinkle; Apocynaceae), though, there’s no doubt. At least twenty-two authorities consider it invasive. It’s easy to find at this time of year. If you follow some of the footpaths near Carderock to the base of the climbing wall, you’ll find vast slopes of the stuff, competing with the Dutchman’s breeches, squirrel corn, Virginia bluebells, and trout lilies that belong there. The plant roots easily at the stem nodes, and since the long stems trail along the ground, it spreads quickly. This characteristic, along with evergreen leaves, pretty purple flowers, and tolerance for a variety of growing conditions, makes it a popular groundcover in home gardens. Please don’t plant it.

next time: more aliens

 

Maples Have Gender Identity Issues

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The earliest blooming wildflower in the Maryland piedmont is skunk cabbage (Symplocarpus foetidus). The flower emerges from wet soils near or in small streams and blooms right there at ground level. It’s probably done now, but our next earliest native plant is blooming, and you have to look up to see it.

Red maple (Acer rubrum, Aceraceae) is one of the most common trees in North America, and ranges from Texas north to Minnesota and all the way to the Atlantic from Florida to Newfoundland. It’s also found in Oregon. Interestingly it’s reported as weedy by some authorities, not surprising since it’s adapted to a wide variety of growing conditions and produces a lot of seed.

While researching maples I had another “plants be complicated” moment, when tripping across a new term: polygamo-dioecious. It seems that some red maples can’t make up their minds whether they’re male, female, or both. Forgive the anthropomorphizing and let me explain.

pistillate flowers on Thalictrum dioicum (early meadow rue)

Flowers can have only pistils (the ovary-bearing or “female” reproductive parts), or only stamens (the pollen-bearing or “male” reproductive parts) or both. Flowers with pistils only are called pistillate, and those with stamens only are called staminate; either type of flower can also be referred to as imperfect. Flowers with both functional pistils and stamens are called perfect.

staminate flowers on Thalictrum dioicum (early meadow rue)

Some species bear perfect flowers only. In other species, each individual plant will bear both pistillate and staminate flowers; this condition is called monoecious, from the Greek words for one (mon) and house (oikos). And in yet other species, individual plants bear only pistillate or staminate flowers; these are plants are termed dioecious (two houses).

perfect flowers of Anemone americana (round-lobe hepatica)

Polygamo-dioecious describes species in which an individual plant bears both pistillate and perfect flowers, or both staminate and perfect flowers. Acer rubrum is one example. And in case you’re wondering (as I did), if there’s a corresponding term polygamo-monoecious, the answer is yes. In these species, an individual plant can bear all three types of flowers: pistillate, staminate, and perfect.

pistillate flowers of Acer rubrum (red maple)

Most maples are polygamo-dioecious, but a few are polygamo-monoecious.

 

 

 

 

glossary
pistil: flower part that bears ovaries (“female”)
pistillate: flower with pistils only
stamen: flower part that bears pollen (“male”)
staminate: flower with stamens only
perfect or bisexual: flower with both pistils and stamens
imperfect or unisexual: flower with only pistils or stamens
monoecious: plant that bears both pistillate and staminate flowers
dioecious: plant that bears only pistillate or staminate flowers, but not both
polygamo-monoecious: plant that bears pistillate flowers, staminate flowers, and perfect flowers.
polygamo-dioecious: plant that bears either pistillate and perfect flowers, or staminate and perfect flowers

Our Earliest Spring Wildflowers

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How many different species are shown blooming in this very small area?

Two days ago the Maryland Biodiversity Project held a single species bio-blitz: submit photos of purple deadnettle (Lamium purpureum) blooming that day. With about an hour to kill before heading out for another activity, I got the camera and went for a walk in a nearby park.

Before finding a few of the target plants, I snapped quick photos of anything else that was flowering. I found hairy bittercress (Cardamine hirsuta), two or three types of speedwell (Veronica species), dandelion, (Taraxacum species), and henbit (Lamium amplexicaule) in open areas, and in the woods snowdrops (Galanthus nivalis) and periwinkle (Vinca minor).

These wildflowers have something in common, other than being our earliest blooming plants: they’re all aliens. The only natives blooming now are skunk cabbage (Symplocarpus foetidus) and some maples (Acer species). And some stupidly early spring beauties, as I reported last week.

This got me thinking. I have pictures of literally hundreds of different species of native wildflowers from the Maryland piedmont alone, but very few of the aliens. I love the natives so much, and find them so interesting, that I ignore the others.

But some of the aliens are rather pretty, and even if they’re weeds, they’re wildflowers, too. So this year I’m going to pay more attention to them, get good pictures, do the research, and feature them here.

There are at least four different species of flowers in the picture above. I can spot purple deadnettle, henbit, hairy bittercress, and one or two of the speedwells.

What, Already?

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On Monday, February 20, after a few days of unusually warm weather, Steve and I went for a short hike in the Carderock-Marsden Tract area, sans camera. I didn’t expect to see any flowers except for skunk cabbage, but I kept my eyes open just in case. We saw lots of spring beauties (Claytonia virginica) emerging, but only four flowering. This is early, but not the only time: in 2013 I found a few spring beauties on February 18. Still, mid-March is when they generally start blooming.

We also spotted a few clumps of Virginia bluebells (Mertensia virginica) just poking up; one had buds. Early April is typically when they they get going.

It’s been delightfully warm, but no, the show isn’t starting yet. Not really.

I did a little research on one of my favorite websites, timeanddate.com, because despite the recent warm weather, we’ve had some unusually cold days, too. Has this been an abnormally warm winter? Have a look:

December historical average high: 48ºF historical average low: 33ºF historical mean: 41ºF
actual high in 2016: 67ºF (on 12/27) actual low in 2016: 17ºF (on 12/16) 2016 average: 41ºF
January historical average high: 44ºF historical average low: 29ºF historical mean: 37ºF
actual high in 2017: 72ºF (on 1/12) actual low in 2017: 15ºF (on 1/8) 2017 average: 42ºF
February historical average high: 47ºF historical average low: 31ºF historical mean: 39ºF
(as of 2/20) actual high in 2017: 73ºF (on 2/8) actual low in 2017: 24ºF (on 2/10) 2017 average: 44ºF

So yes, it’s been about five degrees Fahrenheit warmer these past two months.

In other news, we found several stands of hibernal leaves from cranefly orchid (Tipularia discolor) and four leaves of puttyroot (Aplectrum hyemale).

One other plant has started flowering: lesser celandine (Ranunculus ficaria), a particularly troublesome invasive alien.

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skunk cabbage (Symplocarpus foetidus) [iPhone pic]