Ambrosia artemisiifolia: delcious-sounding name for a very annoying plant

Warning: this plant is considered a noxious weed under the Ontario Weed Control Act.

Such a lovely-sounding name for this plant with such pretty, fern-like leaves! (click the photo to get a better look) If only it weren't for the flowers...

In case you haven't recognized this common but easily overlooked plant yet, it's better known as common ragweed (petite herbe à poux). Those boring little green flowers have no interest for animal pollinators, so ragweed instead releases massive amounts of lightweight pollen into the wind, relying on the sheer quanitity of pollen to ensure that some of it will reach a female flower and fertilize it. (Separate male and female flowers are produced on each plant.)

Ragweed grows in the same habitats and blooms around the same time as its showier cousins, the goldenrods (verge d'or, Solidago spp.). Because ragweed is so inconspicuous, goldenrod is often unfairly blamed for ragweed pollen allergies. In fact goldenrod pollen is too heavy to be wind-borned; that's why it has those gorgeous flowers, to attract the insects needed for pollination.

According to Wikipedia, the genus name Ambrosia comes from the same root, άμβροτος, as the ambrosia which is the food of the gods, but this root word actually means "immortal", referring to the difficulty of eradicating this plant. (This species is actually an annual, so not immortal by any means.)

Ragweed is one of the top 10 herbacious plants to feed wild birds, because it produces numerous, oil-rich seeds. However, given how many people are allergic to it, I think it should be kept to wilderness areas far from humanity, certainly not in Toronto gardens.

Amaranthus tuberculatus in bloom

Amaranthus tuberculatus, known in English as "roughfruit amaranth" or "tall waterhemp" (je ne peux pas trouver un nom commun en français), is an annual native to much of eastern and central North America and a few west-coast states. It can reach two metres in height. The spikes of green flowers are not especially showy, but produce abundant seed, making this a useful food source for birds. The glossy foliage is eaten by the larvae of the common sootywing skipper (Pholisora catullus) and some moths.

Descurainia sophia in bloom

The flixweed (sagesse des chiurgiens) is in bloom, and starting to set seed. Now that it has seedpods, I know that this is non-native D. sophia, rather than native D. pinnata (see details on distinguishing the two). A shame. I do like the lacy bluish foliage.

Hydrangea: flowers in winter

Hydrangea spp., known in English as hydrangeas and in French as hydrangées or hortensias, are shrubs native to south and east Asia, and North and South America.

Here in Toronto, these are probably the only flowers you can see outside in the winter (unless they are buried by snow). The flowers persist for months, drying to a light brown but remaining attractive.

Acalypha rhomboidea: flowers

Acalypha rhomboidea, known in English as common three seed mercury and in French as ricinelle rhomboïde is an annual native to much of eastern and central North America, with spikes of green flowers interspersed with leaves.

These plants volunteered in the garden, and when I found out they were a native plant I couldn't bear to pull them out, even if they aren't conventionally showy. I think they look kind of cool, actually.