This lifeform is found in the SW USA (Texas, New Mexico, and Arizona). This lifeform is found in Mexico.

Agave lechuguilla is native to Texas and northern Mexico. The leaves are usually less than two feet long. The flowers may be yellow, red, or even purple.

Agave genus (century plant) is native to southern North America, Central America, and northern South America.  There are about 300 species of succulent perennials in this large genus.  The large leaves are in rosettes. There are 28 species and 17 recognized subspecies and varieties now growing in greater North America.

Yuccas and Agaves (Family Agavaceae) are sometimes combined with the Amaryllidaceae. Here they are presented as a separate family containing almost 600 species within about 18 different genera. There are 94 species organized into 11 genera now growing in greater North America.

Lily Order (Order Liliiflorae) contains several families many of which are noted for their beautiful flowers. In addition to the rushes, this order contains the well-known lily family. Although some authors combine them with the lilies, here the Amaryllis, Iris, and Agave groups are presented in separate families.

Monocots are a large group of plants usually characterized by having leaves with parallel veins and a seed with a single shell. Most flowers are created with multiples of three. In  the older botany texts, the Monocots were considered more primitive than the Dicots. However, many recent authors have placed the Monocots as an offshoot of the primitive Dicots. Here they are placed before the Dicots.

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.