Tag Archives: invasive species

Plant of the day: pride of Madeira

You’ll see these towering purple spikes looming from road cuts and clifftops. This is pride of Madeira, or Echium candicans. It’s a common sight – especially in more coastal areas. It grows to more than seven feet tall, and is very striking with its gray-green leaves and massive heads of flowers (easily over a foot long).

Sadly, this plant isn’t native to the US. It’s another escaped ornamental species that’s still commonly used in landscaping. Birds and butterflies love it, and deer don’t. In inland areas this isn’t a problem but in the coastal climate it spreads on its own, gradually creeping into wild areas. Because it spreads slowly it is only considered to be moderately invasive, but it’s still not recommended for local gardens.

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Plant of the day: rose clover

There are so many clovers around that they can be daunting to identify. But this little one has long caught my eye—partly because of the pretty pink color of its petals, combined with the many long green teeth of the calyx. But mostly I just like how it invariably has one little leaf coming directly off the flower. It may be strange but I find that adorable. Of course it turns out that botanically speaking the leaf isn’t actually part of the flower, it just appears to be so. In science-speak, the “heads are sessile above the uppermost leaves and stipules”. But that is good enough for me.

Rose clover (Trifolium hirtum) is native to Europe, not California. But it is now so ubiquitous as to be described by the authorities as “one of the most common” of the European species that have naturalized here.

You can pretty much tell rose clover from other species of clover because it has all of the following features: (a) It is hairy but doesn’t get cottony when it goes to seed; (b) Its showy, rosy flowers; (c) It’s an annual not a perennial; (e) That cute little leaf.

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Plant of the day: foxglove

Tall spikes of white or purple flowers are bursting like flares across Marin. This is the season for foxglove, another striking-looking invasive. Native to all parts of Europe, it has now colonized much of North America, where it appears to prefer the coastal areas to the heartland. You can find it in from Alaska to Mexico, and on much of the east coast as well. Digitalis purpurea can grow to be taller than a full-grown person and is quick to colonize areas that have been disturbed such as road sides, logging or building sites.

Foxglove is also highly toxic so don’t eat it!! Small amounts have been known to be fatal. Some of its other names give you a clue that this is a bad idea: Witches’ Gloves, Dead Men’s Bells, Bloody Fingers, and Fairy’s Glove just name a few. Yet in its noteworthy history, Digitalis was also used as a medicinal plant by herbalists. They were on to something: extracts from the plant are now used pharmaceutically to treat congestive heart failure. As much as I appreciate folk remedies, this is one I’m glad the scientific establishment has gotten involved with; messing around with a plant that supposedly killed some kids who drank the water from a vase containing foxgloves seems like a bad idea!

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Plant of the day: French broom

I remember when I was a kid, and first learned that the pretty yellow-flowered bushes I saw all over were bad for the environment. It was probably my first ecological lesson, and I was heartbroken. Their sunny color had always made me happy when I looked out the window on family drives. How could I have been so wrong?

Since then, Genista monspessulana has only become more common. You can see it filling the understory of forests on Mt. Tam, or spilling over the cement retaining walls along roadsides. This highly invasive plant is native to the Mediterranean and the Azores, and was brought to California in the 1800s — probably as an ornamental for gardens. It really is quite pretty. But it also is what scientists call an “ecosystem disruptor” because it wreaks havoc on the native plant communities. It forms dense stands up to 16 feet tall, under which nothing else can survive. All the delicate flowers, grasses and even hardier shrubs perish in its shadow. Livestock don’t even like to eat it. Broom is like an ecological bulldozer, taking diverse habitats and leaving a barren landscape in which it is the only survivor. A single plant has been found to produce over 30,000 seeds — and the seeds live for decades in the soil, waiting for a disturbance like digging (or pulling a grown plant out by the roots) before they sprout. It also is a fire danger, growing tall and tinder dry. Can you tell how I feel about this plant? It’s a nightmare. If you have it on your land or in your neighborhood, get rid of it!! Quick, before it spreads!

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Filed under Invasive, Plant of the day