[Copyright: Richard LeBlond, N.C. Natural Heritage Program]
Least Trillium Trillium pusillum
Description:3-petaled (1.5-3.0 cm) white solitary flower either with or without an erect stalk. Flower turns from white to pink to purple with age. Normally 3 bracteal leaves (green with hint of maroon) and 3 flower sepals (green). Rhizomes horizontal, thin and sometimes branching. Fruits are a pale yellow-green broadly ovoid about 1 cm broad.
Life History:Perennial. Flower: March-May. Fruit: June-July.
Habitat:Typically grows in the acidic soils of moist forests along small streams while some varieties may prefer calcareous or mafic soils.
Distribution:Occurring in disjunct fragmented populations across the southern U.S. south of WV & MD excluding FL and west to OK
Status:As of October 6, 2006 NatureServe lists the following State Status for the species: AL & TN = Imperiled; GA, KY, MS, NC, & SC = Critically Imperiled
Flora size in North America is greatest in the southeastern United States. The high diversity may be related to the region's warm, humid climate, which is thought to be favorable for plant growth (Sisk, 1998).
The U.S. Department of Agriculture PLANTS database lists 18,527 plant species within the states of Alabama, Kentucky, Missisippi, and Tennessee [view data records].
Of these, the PLANTS database lists 858 species recognized by state or federal agencies as threatened or endangered species [view data records].
State-listed Noxious Weeds The USDA PLANTS database identifies 132 species in Alabama [view records], nine species in Mississippi [view records], nine species in Kentucky [view records], and three species in Tennessee [view records].
Wetland Indicator Plant Species
The USDA PLANTS database lists 2550 plant species that are wetland indicators in Alabama, Kentucky, Mississippi, and Tennessee [view records].
Literature Cited
Sisk, T.D. (1998). LUHNA Chapter 4: Changing Patterns in the Number of Species in North American Floras. Retrieved January 16, 2008, from LUHNA Homepage (Land Use History of North America) Web site: http://biology.usgs.gov/luhna/chap4.html
Below are additional resources and information from the NBII online resources catalog pertaining to plants and regional flora in the southeastern United States.
Introduction to Plants
Basic Plant Information
Plants are organisms which belong to the plant kingdom. Commonly multicellular, plants produce energy to grow and reproduce by converting light energy radiated from the sun into food through the process of photosynthesis.
Plants can be classified as either vascular or nonvascular. Vascular plants have a specialized conductive system known as vascular bundles, a group of specialized cells made up of xylem and phloem. Nonvascular plants lack these conducting tissues.
Vascular Plants include club mosses, ferns, cycads, gymnosperms, and angiosperms.
Cycads: Among the oldest plants, Cycads bear resemblence to palms and are native in South America, Africa, and Australia.
Gymnosperms: Seed-bearing woody vascular plants, such as the conifers (pine, spruce, fir, etc.), whose seeds are not enclosed in an ovary or fruit, but are exposed.
Angiosperms: Flowering plants that periodically produce flowers which have various parts including sepals, petals, stamens, and carpels.
Nonvascular plants include liverworts, hornworts, and mosses.
Mosses: Simple green land plants, member of the phyla Bryophyta, along with liverworts and hornworts. They have leaves and a stem, but always lack roots.
Liverworts and hornworts: Simple green land plants of the phyla Bryophyta with leaves and a stem and always without roots.
The NBII Program is administered by the Biological Informatics Office of the U.S. Geological Survey
