In honor of National Invasive Species Awareness Week, my next plant id book review will focus on weed identification. An obviously important part of becoming more “weed aware” is to know the names of the weeds you are looking at. Once you know the name of the weed then you can start figuring out what to do about it.

As in my review of wildflower identification guides, my focus with weed identification guides is on those for the western United States. It’s not that I’m biased towards the west (though maybe I am), its just the west happens to be where I live and work with weeds.

I tend to spend a lot of time in weed id field guides. In addition to teaching weed identification in the lab for USU’s weed biology and control class, I also train our summer field workers in weed id. Though nothing can substitute for having an actual, live plant to learn identification from, a lot of times when we are getting ready for field season and training workers there aren’t a lot of real, live plants available. So pressed specimens and field guides have to be used, at least initially.

Technically this week I am reviewing 4 guides, but two of them are sort of companion guides, so they will be looked at together. I’ll state up-front that I purposely excluded the Weeds of California and Other Western States guide, for the following reason: it’s just too. darn. big. Now that’s not to say that it isn’t worth it to have if you are a land manager and require more information than the guides below provide. It is very well done; a two-volume set, it is incredibly comprehensive and includes A LOT of species. But, it is more technical than most lay-people would like (or need), and it is impractical to carry around with you for a quick reference.

That being said, I now present to you some useful guides for identifying those pesky weeds.

Weeds of the West, published by the Western Society of Weed Science, is probably the guide I refer to the most. But in terms of visual appeal and ease of use, it’s not necessarily my favorite. It’s organized by family, which as I mentioned in the wildflowers post isn’t my favorite organization for people who are unfamiliar with plants. However, there is a key to plant families included in the back of the book, which makes it fairly easy to identify your species to family before you then search through the book.

 

The entry for yellow starthistle in Weeds of the West.

The entry for yellow starthistle in Weeds of the West.

Highlights:

  • Perhaps not quite as comprehensive as the Weeds of California and Other Western States, it is nonetheless a good representation of the variety of weedy species found throughout the West.
  • Each weed gets a two-page spread, with one large whole-plant picture, as well as a few other smaller, more detailed photos of key characteristics.
  • The glossary in the back is helpful for understanding identification terms
  • The family key is helpful for narrowing down your search options
  • An index, including both scientific and common names, is a nice feature for quick reference to plants you have already identified

Lowlights:

  • The text is written in paragraph form, and not standardized by what attributes or key characteristics are included
  • Organization is strictly alphabetical starting with family, then genus and species, which means you could end up doing a lot of paging through to find the species of interest
  • Not spiral bound

New Invaders of the Southwest and New Invaders of the Northwest are two guides released by the USDA Forest Service. As their names imply, the focus of these companion guides are on species that are considered to be newly invading in the southwestern and northwestern United States.

The distribution maps are helpful, but this one is already out of date as elongated mustard has been documented in Cache County, Utah.

The distribution maps are helpful, but this one is already out of date as elongated mustard has been documented in Cache County, Utah.

As you can see, the format for the Weeds of the Southwest is very similar to the Weeds of the Northwest guidebook.

As you can see, the format for the Weeds of the Southwest is very similar to the Weeds of the Northwest guidebook.

Highlights:

  • Two-page spreads for all of the weeds included
  • Multiple photos, as well as a distribution map are helpful for correct identification (though, because of the mobile nature of weeds, the distribution maps may quickly become outdated)
  • Organized by flower color
  • Text is all organized the same for each plant

Lowlights:

  • Within each flower color section, the organization seems random – not alphabetical by common name or scientific name
  • Text can be a lot to read through quickly, but not terribly bad

Common Weeds of the Yard and Garden: a guidebook is another guide published by Utah State University. I think that this one is the one that is probably most useful for the general homeowner/gardener. The authors acknowledge in the introduction that they couldn’t possibly include every weed that occurs on readers’ properties, but that it is simply a compilation of 50 common ones.

Common Weeds of the Yard and Garden is a compact, concise reference guide.

Common Weeds of the Yard and Garden is a compact, concise reference guide.

Highlights:

  • The small dimensions of the hard copy make it handy to carry around, but it is also available as a .pdf  on the USU extension website (sidenote: the Utah noxious weed field guide that is also available here is outdated and will soon be replaced, so if you are interested, shoot me message and I’ll be sure to let you know when the new one is available)
  • Each weed has a two page spread – text on the left side, with at least two photos of the weed on the right
  • The text is all organized the same, and though the descriptions are kind of wordy, it is still fairly easy to pick out the main points.

Lowlights:

  • It’s organized alphabetically by the scientific names for family, genus, and species but at first glance it doesn’t appear that way since the main headings are the common names
  • Only 50 weeds are included, so it is likely that something that is a problem for you may not be described

 

What resources have you found helpful for identifying weeds? If you’ve found this helpful, please share it with your friends!