This lifeform is widespread in North America. The white color will help identify this lifeform. This lifeform is found in swamps or very moist ground. This lifeform is locally common in suitable environments.

Water parsnip (Sium cicutaefolium to Sium cicutifolium to Sium suave) is found from Nova Scotia to British Columbia, and south to Florida, Louisiana, and California. This plant's variable leaf-form could cause it to be mistaken for Queen Ann's lace. However, the aquatic habitat and different leaf shape easily separate the two species.

Sium genus is native to the Northern Hemisphere and also South Africa.  There are about ten species in this genus.   These are slender plants with tap roots that have a preference for marshes and swamps.  These plants have large compound umbels of white flowers.  There are two species established in North America.  Both of these species appear to be native to North America.

Carrot Family (Ammiaceae to Umbelliferae to Apiaceae) is a large family of about 3,000 species most of which occur in the Northern Hemisphere. Although many of the species in this family are eaten for food, there are several similar species that are poisonous. There are 404 species organized into 84 genera now living in greater North America.

Carrot or Umbel Order (Umbelliflorae Order) can be recognized by the fact that their flowers are usually arranged in a radial symmetric pattern called an umbel.

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.