Tag Archives: weeds

Plant of the day: Scotch broom

This is another badnasty invasive broom species that you’ll see frequently throughout the Bay Area. Scotch broom (Cytisus scoparius) has pretty yellow pea-like flowers and long, narrow leaves that press closely against its multi-sided stems. Though it occasionally has some rounded leaflets as well, the overall lean, linear look to its foliage makes it easy to tell from its French broom cousin that I wrote about a few weeks ago.

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In California, French broom is a nastier problem than Scotch broom, but throughout the rest of the country the Scottish Cytisus scoparius is the worst broom around. Even worse, both were deliberately originally introduced as ornamental species!

This plant is so nasty because it is hearty and vigorous, and spreads fast because it produces a LOT of seeds. A single Scotch broom plant can live for up to 7 years, and produce over 150,000 seeds per year. It’s a mind-boggling number! The seeds stay in the ground, ready to sprout, for between 5 and 30 years. These plants grow up to 12 feet tall and smother any native plants that would otherwise have grown where they are. There’s no sharing if you’re a broom species! Scotch broom is a rampant invasive across much of the western and eastern seaboards of North America – from Alaska to Baja and from Maine to Georgia, as well as in other countries like Australia and New Zealand. It’s native to northern Africa and parts of Europe.

There is one more broom species that you might see in the area, and that’s Portuguese broom. It’s not nearly as common, but it does cover about 65 acres in the Marin Headlands where it was planted in the 1960s as part of a landscaping and slope stabilization program – another good idea gone wrong! Portuguese broom looks a lot like Scotch broom, except the seed pods are inflated instead of compressed around the seeds. Also they have 8-10 sided twigs, as opposed to the 5-sided twigs of Scotch broom.

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Filed under Invasive, Non-native, Plant of the day

Plant of the day: common catchfly

Common catchfly

This plant is a weed, but I kinda like it. The whole plant is sticky (is that why it’s called catchfly?) and the small pinkish-white flowers are perched atop a vase-shaped calyx. The petals are fused together, with little toothlike projections sticking up like a fringe around the inner edge. There are distinctive stripes running perpendicularly along the calyx (which is all the sepals taken together). The whole thing is a nice bit of floral architecture – if you can forget that it’s an invasive that was introduced from Europe!

Also, Silene gallica is another member of the Caryophyllaceae (a.k.a pink, or carnation) family. So check for the swollen nodes where the opposite pairs of leafs join the stem that I talked about a few posts back!

You may wonder why I always talk about families – the reason is that whether you are keying or looking plants up in a guidebook, being able to confidently narrow your options down to one or two families makes the whole process a lot easier. It also helps train your eye and mind in the detailed way of looking at plants that is needed for good identification.

Silene Gallica

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Filed under Non-native, Plant of the day