Narrative
Western spring beauty (Claytonia lanceolata) has eight named varieties listed in Kartesz. This small perennial rarely exceeds eight inches in height. The flower petals are typically white-pink with darker pink veins.
This lifeform is generally found west of the Continental Divide in North America
Claytonia genus is native to North America, with most species native to western North America. However, this genus is also represented in South America, Asia, and Australia. These plants are generally perennial succulent glabrous herbs with thick rootstocks. There are 25 species and 30 named subspecies living in greater North America.
Purslane Family (Portulacaceae) contains about 500 species organized into sixteen to twenty 16-20 different genera. There are eight genera and 105 species now growing in greater North America.
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.
|