Salvia is the largest kind of plants in the Minit Family with nearly 1000 species of shrubs annually. It  is one of  the several  kinds that  commonly referred to as sage.

This kind is distributed throughout  the  Old  World  and  the  Americas, with three  distinct  regions  of  variety:

Central  and  South  America ; Central  Asia  and  Mediterranean ; Eastern  Asia (90 species).

Description:

Salvia species  include  annual, biennial, or  perennial  herbs, along with woody subshrubs. The stems are typically angled like other members of  Lamiaceae. The leaves  are  typically  entire, but  sometimes  toothed or  pinnately divided. The flowering stems bear small bracts, dissimilar to the basal leaves in some species,  the  bracts are  ornamental  and  showy.

The  flowers  are  produced  in  clusters or  panicles and  generally  produce  a showy  display  with  flower  colors  ranging  from  blue  to  red, with  white  and yellow  less  common. The   calyx  is  normally  tubular  or  bell-shaped, without bearded  throats, and  divided  into  two  parts  or  lips, the  upper  lip entire  or three-toothed, the  lower  two-cleft. The corollas are often paw shaped and are two-lipped. The upper lip is usually entire or three-toothed. The lower lip typically has two lobes. The stamens  are  reduced  to  two  short  structures  with anthers  two-celled, the  upper  cell  fertile, and  the  lower  imperfect. The flower  styles  are  two-cleft. The  fruits  are  smooth  ovoid  or  oblong  nutlets  and  in many species, they have a mucilaginous coating.

Many members of  Salvia  have  hairs growing  on  the  leaves, stems, and  flowers, which  help  to  reduce  water  loss  in  some  species. Sometimes  the hairs  are  glandular  and  secrete  volatile  oils  that  typically  give  a  distinct aroma  to  the  plant. When  the  hairs  are  rubbed  or  brushed, some of  the  oil-bearing cells are ruptured, releasing  the  oil. This  often  results  in  the  plant being  unattractive  to  grazing  animals  and  some  insects.

Staminal  lever  mechanism

The  defining  characteristic  of  the  genus  Salvia  is  the  unusual  pollination mechanism.

It is central to any investigation into the systematics, species radiation, or  pollination  biology  of  Salvia. It is  instead  of  the typical four found in other members of  the  tribe  Mentheae consists  of  two  stamens and  the  two thecae  on  each stamen are separated by an elongate connective. It  is  the  elongation of  the  connective  that  enables  the  formation  of  the  lever  mechanism.

It believed  that  the  lever  mechanism  is  a  key  factor  in  the  speciation, adaptive radiation, and  diversity  of  this large  genus.

History

George Bentham was first to give a full monographic account of the genus in 1832-1836, and based his classifications on stamina morphology and it is still

the only comprehensive  and  global  organization of  the  family.

He  was  less  confident about  his  organization  of  Salvia. At  that  time,  there  were  only  291  known  Salvia  species.

Subdivision:

Bentham  eventually  organized  Salvia  into  twelve  sections (originally fourteen), based  on  differences  in  scyphus , pappus, flag. These  were  placed  into four  subgenera  that  were  generally  divided  into  Old  World  and  New World  species.

His system is still the most widely studied classification  of  Salvia, however, more  than  500  new  species  have  been  discovered  since  his  work.

Other botanists  have  since  offered  modified  versions  of  Bentham’s  classification system while  botanists  in  the  last  hundred  years  generally  do not  endorse Bentham’s  system.

Salvia was  monophyletic, meaning  that all  members of  the genus evolved  from one  ancestor.

However, the  immense variety  in  stamina  structure, vegetative  habit and  floral  morphology  of  the species  within  Salvia  has  opened  the  debate  about its infrageneric  classifications.

Selected species and their uses

Many species are used as herbs, as ornamental plants (usually for flower interest), and sometimes for  their ornamental  and  aromatic  foliage. The  Plant  List  has 986  accepted  species  names.

Hybrids

Many inter specific hybrids occur naturally, with a relatively high degree of cross ability, but some of them have  been intentional. A natural hybrid has given rise to a series of  popular ornamentals.

Etymology

The name Salvia derives from the Latin severe. the verb related to sales , referring to the herb’s healing properties.

Pliny the Elder was the first author known to describe a plant called “Salvia” by the  Romans, likely  describing the type species of the genus Salvia, Salvia officinalis.

The  common  modern  English  name  sage derives from Middle English sawge, which was borrowed from Old French sauge, and like the botanical name stems from Latin salvere. When used without modifiers, the name ‘sage’ generally refers to Salvia officinalis . however, it is used with modifiers to refer to any member of the genus. The ornamental species are commonly referred to by their genus name Salvia