The Weedalogue, a Catalogue of Weeds.
The Weedalogue is a project to identify the weeds known in Philadelphia Pennsylvania.
Ralph Waldo Emerson once said: "What is a weed? A plant whose virtues have not yet been discovered."
My experience and research suggests that Emerson was wrong. I would say that it is closer to the truth to say that a weed is a plant whose virtues have been forgotten. Quite a few (much more than half) of the herbaceous plants included in this compendium were used either as a food source or medical product in times gone by, and in many cases, still today.
I have not endevoured to explore or elaborate on the uses of each plant. Once if is positively identified (and that means more than taking my unprofessional word for it), the user can research the virtues of the plant elsewhere online with a simple search engine.
The exception to this is edible plants. One of my reasons for starting this research was to discover which plants in my gardens are edible. Lambsquarter was one of my primary green vegetables for a few summers in a row. I would eat my way through weeding my garden plot at Broad and South.
So we are left to redefine the term "weed." To me, a weed is any plant which decided of its own nature to grow somewhere it wasn't intended to (by human standards). This means that the term here covers, in practical usage, any self-established plant. There is, indeed, a fine line between a weed and even cultivated ornamentals and crops. Many of what are now listed as invasive weeds were at one time introduced from Europe or elsewhere as ornamentals, cover crops or the like. The line is certainly a fine one. Butterly bushes, for instance, sold as gorgeous ornamental plants have been discovered to be invasive and are starting to naturalize. Some of the plants included here such as the afore-mentioned butterfly bush, spiderflower, petunia, perilla, peppermint, hollyhocks, rose of sharon and others would be usually considered herbs or ornamental plants rather than weeds by most gardeners, and I agree, to a point. In reality, it would have been more accurate to call this a catalogue of invasive plants.
It should also be stated that I make no difference between weeds and wildflowers. The term "wildflower" here has no practical meaning, since all of the weeds yet included fall into the category of magnoliophyta, or flowering plants. The term is one of judgement. A weed appreciated for its pleasing flowers is considered a "wildflower."
In selecting plants to include here, I made a few conditions. I had to find at least one specimen of the species where it was almost certainly self-established. One cannot ever be entirely certain, so I settled for a 90% certainty. Anything found growing out of a pavement crack or building foundation was given automatic inclusion. The second condition was that it must have been found within the limits of Philadelphia. This includes such areas as Chestnut Hill, Germantown and West Philly but not the surrounding suburbs. All of the photographs included here were taken within the limits of Philadelphia.
The weeds included here generally fall into one of three categories: grasses, forbs and trees with only some dabbling in other territories, such as fungi. Grasses are tough to identify, so I have only made a start at them, with a few of the easier common grasses. Forbs, or herbaceous plants, make up the bulk of the entries. Trees make up the second largest part of the entries. Any gardener will attest that tree seedlings make up a large part of the weeds they have to remove from their gardens. It should probably be noted that the term "tree" has no biological foundation. It is simply a conventional word for large upright woody plants. In the same genus, one may find trees, shrubs and vines, for instance. Despite this, I have included a "tree index" arranged by taxonomy.
In supplying photographic imagery of the plants, I have in many cases given examples of the plants under cultivated circumstances. This allows a more well-rounded view of the plant. This is especially important in the case of naturalized or naturalizing plants. In the case of trees, such as the London planetree, I thought it best to show the full-grown planted specimens in the local parks that actually generate the hundreds of seedlings, rather than just show the seedlings.
Most of the research for this project was done online, with some help from fellow gardeners and some book research. The accuracy of any statement or plant identification is not guaranteed. Corrections have already been made and I am certain that many will be made in the future.
It has become painfully apparent that scientific taxonomy of plants is far from perfect and many sources disagree on many species. I started the project by following what seemed to be a general consensus, but have revised the project to now generally follow the system set out by the U.S.D.A. on their "PLANTS National Database".