Narrative

Chaff flower (Alternanthera ficoidea) is found from Mexico south to Brazil. There are several named subspecies or varieties. This annual has a striate stem. This is usually found as a creeping species.

This lifeform is found widely in the New World tropics.

Alternanthera genus is native to tropical and semi-tropical areas in the New World. There are about 200 annual and perennial herbs in this genus. Several of these herbs are floating species. At least 14 of these species of Alternanthera are now established in greater North America.

Amaranthaceae family (amaranth) contains about 70 genera and about 800 species. These are mostly herbs, but some exotic low shrubs are in the family. The leaves can be alternate or opposite, usually entire, and usually thin. The small flowers are in terminal spikes or axillary heads. There are no petals. This family had 19 genera and 111 species growing in greater North America as of 1994.

Centrosperm (Centrospermae) order is a large order composed of several families.

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 (Aster) 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.