This lifeform is found north of the Mason Dixon line in North America. This lifeform is very common in suitable environments.

American Basswood (Tilia americana) is found from New Brunswick to Georgia, and west to Nebraska and Texas. One characteristic of Basswoods, of which there are several in the United States, is the large heart-shaped leaves. American Basswood has the largest leaves, up to five to six inches or longer with uneven bases. These trees can grow to 125 feet in height although most specimens barely reach seventy feet.

Tilia genus is native to the northern temperate regions of the world.  There are about 45 species.  This genus is also represented in the mountains of Mexico.  These are trees with cordate leaves.  An unusual feature of these leaves is the unequal size of the two basal lobes.  There were four species, one hybrid, and three subspecies growing in greater North America as of 1994.

Linden Family (Tiliaceae) is a group of 700 species arranged into about 50 different genera widely distributed in the tropical zones and extending into the cooler climates. These are mostly trees and shrubs with alternate simple leaves. There are 19 species arranged in five genera growing in greater North America.

Malvales are a group of woody plants and herbs generally limited to the tropics. However, there are a few species in the United States.

Dicots (Dicotyledoneae Class) are the predominant group of vascular plants on earth. With the exception of the grasses (Monocots) and the Conifers (Gymnosperms), most of the larger plants that one encounters are  Dicots. Dicots are characterized by having a seed with two outer shell coverings. Some of the more primitive Dicots are the typical hardwood trees (oaks, birches, hickories, etc). The more advanced Dicots include many of the Composite Family flowers like the  Dandelion, Aster, Thistles, and Sunflowers. Although many Monocots reach a very high degree of specialization, most botanists feel that the Dicots represent the most advanced group of plants.

Seed plants (Phylum Embryophyta) are generally grouped into one large phylum containing three major classes: the Gymnosperms, the Monocots, and the Dicots. (Some scientists separate the Gymnosperms into a separate phylum and refer to the remaining plants as flowering plants or Angiospermae.)

For North American counts of the number of species in each genus and family, the primary reference has been John T. Kartesz, author of A Synonymized Checklist of the Vascular Flora of the United States, Canada, and Greenland (1994). The geographical scope of his lists include, as part of greater North America, Hawaii, Alaska, Greenland, Puerto Rico, and the Virgin Islands.

Kartesz lists 21,757 species of vascular plants comprising the ferns, gymnosperms and flowering plants as being found in greater North America (including Alaska, Hawaii, Greenland, Puerto Rico and the Virgin Islands).

There are estimates within the scientific world that about half of the listed North American seed plants were originally native with the balance being comprised of Eurasian and tropical plants that have become established.

Plant kingdom contains a large variety of different organisms including mosses, ferns, and seed plants. Most plants manufacture their energy from sunlight and water. Identification of many species is difficult in that most individual plants have characteristics that have variables based on soil moisture, soil chemistry, and sunlight.

Because of the difficulty in learning and identifying different plant groups, specialists have emerged that study only a limited group of plants. These specialists revise the taxonomy and give us detailed descriptions and ranges of the various species.  Their results are published in technical journals and written with highly specialized words that apply to a specific group.

On the other hand, there are the nature publishers. These people and companies undertake the challenging task of trying to provide easy to use pictures and descriptions to identify those species.