Plants

• Certain true sages, members of the genus Salvia
  Salvia
  Salvia is the largest genus of plants in the mint family, Lamiaceae, with approximately 700-900 species of shrubs, herbaceous perennials, and annuals. It is one of several genera commonly referred to as sage. When used without modifiers, sage generally refers to Salvia officinalis ; however, it is...
  
  , are referred to as purple sage:
  • Salvia dorrii
    Salvia dorrii
    Salvia dorrii is a herbaceous perennial in the family Lamiaceae. It is native to mountain areas in the western United States and northwestern Arizona, found mainly in the Great Basin Range habitat and southward to the Mojave Desert, growing in dry, well draining soils...
    
    , also called Ute tobacco sage, Dorr's sage, etc., which has showy purple flowers. It is a mild hallucinogen when smoked, and is used in Native American ceremonies and Native American herbal medicine. It is native to the western United States
    United States
    The United States of America is a federal constitutional republic comprising fifty states and a federal district...
    
    , including Utah, and has been identified as the plant Grey had in mind.
  • Salvia leucophylla
    Salvia leucophylla
    Salvia leucophylla is an aromatic sage native to the southern coastal mountain ranges of California and Baja California.-Taxonomy:The plant's specific epithet, leucophylla, describes the light grayish leaves...
    
    , also called San Luis sage, likewise producing showy purple flowers, native to California
    California
    California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
    
     and Baja California
    Baja California
    Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
    
     and used in xeriscaping in southern California.
  • Salvia pachyphylla
    Salvia pachyphylla
    Salvia pachyphylla is a perennial shrub native to California, Nevada, and Arizona. In California, it grows between elevation on dry rocky slopes, blooming from July to September. It reaches high, with blue-violet flowers, rarely rose, growing in dense clusters.- External links:****...
    
    , called giant-flowered purple sage, blue sage, etc., a shrub native to California and bordering areas, used in xeriscaping in colder regions.
  • Salvia officinalis "Purpurascens", the purplish-leaved variety (or group of varieties) of the common sage.
• Leucophyllum frutescens
  Leucophyllum frutescens
  Leucophyllum frutescens is an evergreen shrub in the figwort family, Scrophulariaceae, native to the state of Texas in the southwestern United States and the states of Coahuila, Nuevo León, and Tamaulipas in northern Mexico. Although commonly known as Texas Sage, it is not a true sage and is...
  
  , also called Texas sage, barometer bush, etc., a purple-flowered shrub of Texas
  Texas
  Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
  
   (where it is the official state native shrub) and Mexico
  Mexico
  The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
  
  . Though it has been considered "the purple sage of cowboy song fame," it is not the plant of Grey's novel, as it is known in the U.S. only from Texas.
• Psorothamnus
  Psorothamnus
  Psorothamnus is a genus of plants in the legume family. These are shrubs and small trees. Many are known by the general common name indigo bush. Some are referred to as daleas, as this genus was once included in genus Dalea. These are generally thorny, thickly branched, strongly scented bushes...
  
   scoparius, formerly Dalea scoparia and more often called broom dalea, a purple-flowered, nearly leafless shrub found in Texas, New Mexico
  New Mexico
  New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
  
  , Arizona
  Arizona
  Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
  
  , and Mexico.
• Sagebrush
  Sagebrush
  Sagebrush is a common name of a number of shrubby plant species in the genus Artemisia native to western North America;Or, the sagebrush steppe ecoregion, having one or more kinds of sagebrush, bunchgrasses and others;...
  
  es (Artemisia), loosely called sage, which are dominant plants in parts of Utah. They have been identified, tentatively and definitely, as the plant Grey had in mind. The purple color would be that of aerial perspective
  Aerial perspective
  Aerial perspective or atmospheric perspective refers to the effect the atmosphere has on the appearance of an object as it is viewed from a distance. As the distance between an object and a viewer increases, the contrast between the object and its background decreases, and the contrast of any...
  
  , as Grey mentioned:

The sage about him was breast-high to his horse, oversweet with its warm, fragrant breath, gray where it waved to the light, darker where the wind left it still, and beyond the wonderful haze-purple lent by distance.

Other uses

• Riders of the Purple Sage
  Riders of the Purple Sage
  Riders of the Purple Sage is Zane Grey's best-known novel, originally published in 1912. Most critics agree that it played a significant role in shaping the formula of the popular Western genre.- Plot in a paragraph :...
  
  , a novel by Zane Grey
• Riders of the Purple Sage (band)
  Riders of the Purple Sage (band)
  Riders of the Purple Sage was a name used by three separate western bands in the United States.The original Riders of the Purple Sage was formed in 1936 by singer and guitarist Buck Page. The group spent three years as the staff band for radio station KDKA in Pittsburgh, performing five hour-long...
  
  , a name used by three separate western bands in the United States
• New Riders of the Purple Sage
  New Riders of the Purple Sage
  New Riders of the Purple Sage is an American country rock band. The group emerged from the psychedelic rock scene in San Francisco, California in 1969, and its original lineup included several members of the Grateful Dead. Their best known song is "Panama Red"...
  
  , an American country rock band, or New Riders of the Purple Sage (album)
  New Riders of the Purple Sage (album)
  New Riders of the Purple Sage is the self-titled debut album by the American country rock band the New Riders of the Purple Sage. It was released by Columbia Records in 1971, and reached number 39 on the Billboard charts....
  
  , their debut album
• Purple Sage, Wyoming
  Purple Sage, Wyoming
  Purple Sage is a census-designated place in Sweetwater County, Wyoming, United States. The population was 413 at the 2000 census.-Geography:Purple Sage is located at ....
  
  , a census-designated place in Sweetwater County, Wyoming
• Open-source software for arithmetic geometry, closely related to Sage.