Botanists know when they are home. You could blindfold us, fly us around the world and drop us in random ecosystems. We would know when we were back in our climate, geology and ecosystem, because when we see that familiar assemblage of plants, we kn

ow we are home. That sense of home we all have and feel, but botanists can raddle off species names that make that place special.
With the trading and gardening of plants from abroad that has undoubtably been happening since humans figured out the shovel, ecosystems around the world are less and less different. And this is speeding up the more we trade and travel. I call it the homogenization of our ecosystems. Humans are reconnecting once isolated areas back to one. Isolation that created diversity, that made species evolve strange shapes, behaviors and colors is disappearing. With these barriers broken down, species are having to compete with new arrivals. That cute Trailing Blackberry of Oregon is having to contend with the more vigorous, fecund, and gladiator-like Himayalan Blackberry. As much as this is a battle for resources on the ground, its also a big shift in the ecosystem: what species are around and how they interact.
For the past few months I’ve been living in a cute village, Ballinafad, in County Sligo, Ireland. Ireland is green year around, like my hometown Portland, Oregon. We also have other similarities besides rain: good beer, similar temperature and climate and many of the same plants.
As ecologists, we manage land to increase the diversity and abundance of of native flora and fauna. Often this translates into removing alien species and replanting or re-introducing native species. Western Ireland is full of the same foreign weeds that we have in Portland. Here’s a partial list of our
common introductions:
Traveller’s Joy
Clematis vitalba, Indian Balsam
Impatiens glandulifera,
Polygonum cuspidatum (Japanese knotweed),
Convolvulus sepium (bindweed), Laurel
Prunus laurocerasus, Poison hemlock
Conium maculatum, Fennel
Foeniculum vulgare, Bracken Fern
Pteridium aquilinum (ok, it is native to both places, but is sometimes battled in both places, like
Juncus effusus as well),
Melilotus altissimus, Giant Hogweed
Heracleum mantegazzianum, Sycamore, Hedge and Norway maple
(Acer pseudoplatunus, campestre and
platanoides), Horse chestnut
Aesculus hippocastanum, Milk thistle
Silybum marianum, Periwinkles (
Vinca minor and major), Nipplewort
Mycelis muralis, Tansy
Tanacetum vulgare, Butterfly bush
Buddleja davidii, Italian Ryegrass
Lolium multiflorum, climbing polygonum
Fallopia convolvulus, and Beech
Fagus sylvatica.
Some of the above species spread very fast and are problems in many areas of the world. The next list, which includes
some of Portland’s most invasive plants are all native to Ireland.
Reed Canary Grass
Phalaris arudinacea, English Ivy
Hedera hibernica, Holly
Ilex aquifolium, Giant Reed Grass
Phragmites australis , European beach grass
Ammophila arenaria, Herb Robert
Geranium robertanium, three other Geraniums
(molle, dissectum, lucidum), Mullein
Verbascum thapsus, False Brome
Brachypodium sylvaticum, St. John’s Wort
Hypericum perforatum, Ranunculus acris, Wood Avens
Geum urbanum, Bitter sweet nightshade
Solanum dulcamara, Purple loosestrife
Lyth
rum salicaria, Rowan tree
Sorbus acuparia, Privet
Ligustrum vulgare, Hawthorn
Crataegus monogyna, Hazel
Corylus avellana, Gorse
Ulex europaeus, Garlic Mustard Alliaria petiolata, Teasel
Dipsacus fullonum, Yellow Iris
Iris pseudocorus, Thistles
Circium vulgare and
arvense, Brown knapweed
Centaurea nigra, Ox-eye daisy
Leucanthemum vulgare, Birch
Betula pendula, Water milfoil
Myriophyllum, Plantain
Plantago lanceolata and
major, Broad-leafed Orchid
Epipactis helleborine, Cock’s foot
Dactylis glomerata, Cleavers
Galium aparine, Cat’s ear
Hypochoeris radicata, Montbretia
Crocosmia x crocosmiflora, Tall Fescue
Festuca arundinacea, Carrot
Daucus carota, Cow-parsley
Anthriscus sylvestris, Bent grass
Agrostis stolonifera and
capillaris, Red Fescue
Festuca rubra, various clovers
Trifolium repens, arvense and
pratense, Sowthistles (
Sonchus spp.), Docks
Rumex obtusifolius, crispus, acetosella, Dandelion
Taraxacum spp., Bird’s-foot trefoil
Lotus corniculatus, Rye grass
Lolium perenne, Creeping buttercup
Ranunculus repens, Lesser clandine
Ranunculus ficaria, and a few other grasses. This gets strange when a species like Bird Cherry,
Prunus avium, here in Ireland is rare and protected, and in a site in Portland I’m trying every chemical and machine to remove it from a natural area. These species in Ireland are important for the ecosystem: for the birds, insects, and soil, but in Portland are pushing out our trilliums, daisys and Oregon Grape.
And this migration goes both ways. I’ve seen hedgerows, either planted, or slowly being taken over by plants I know as native in Portland. These give me a warm hearted feeling of home, but I know they are just misplaced, and a bit out of control here. Snowberry
Symphoricarpos albus, Douglas’s Spirea
Spirea douglasii, Fireweed
Epilobium angustifolium (which actually is a native in Ireland in rocky places, but is invading bog margins from foreign strains) ,
Epilobium ciliatum, Fringecup
Tellima grandiflora, Monkey flower
Mimulus guttatus, Blue-eyed grass
Sisyrhinchium californicum, Red Flowering currant
Ribes sanguineum, and Red Osier Dogwood
Cornus sericea (stolonifera) are all spreading here. Also the Irish have replanted many of their bogs and uplands with conifers native to Oregon including Western Red Cedar
Thuja plicata, Douglas Fir
Pseudotsuga menziesii, and the very common Sitka Spruce
Picea sitchensis and Lodgepole pine
Pinus contorta. The mink, a native weasel from Oregon has been introduced here as well and is feasting on chickens’ and rare tern eggs every spring.
And you would think a small island in the North West of Europe and a continental city 9 times zones away wouldn’t have
common species but we do. Our swallows are the same species and we have a few plant species as well, such as the common rush
Juncus effusus (OK, different varieties, but same species anyways), the Stinging Nettle (
Urtica dioica, some contention here too), Cattail, or called Reed Mace in Ireland
Typha latifolia, the Bullrush
Scirpus (Shoenoplectus) lacustris, Bracken Fern
Pteridium aquilinum, Bearberry
Arctostaphylos uva-ursi, Yarrow
Achillea millefolium,Toad rush
Juncus bufonius, Lady Fern
Athyrium felix-femina, and Deer Fern
Blechnum spicant. Also the wetland grasses
Deschampsia caespitosa and
Alopecurus geniculatus are native to both places as well as the sedge
Eleocharis palustris What causes big evolutions of some species and not in some in nothing less than fascinating.
After spending years in Oregon cutting ivy from trees, clearing the forest of garlic mustard and Hawthorn and Holly, I got full of hatred for these species. Then living and being a biologist in Ireland has forced me to re-look at these species. To see them as they are: Almost perfectly evolved where they are native (here) and just a bit too successful where I’m going back to (Oregon). No, don’t get me wrong, I wo

n’t put down the sprayer or chainsaw, but I might at least apologize for my killing the introduced species. Maybe not shed a tear, but realize ,in the end, we are all just struggling for our own existence, our own continuation, and I can’t knock any species for it. But I’ll still remove them to help save what dwindling native diversity remains. If no action is taken place, our ecosystems will look the same, the same species in similar climates, and our sense of home will be lost, our unique species will be pushed out by those hardened species.