The Asteridae
Family Overview - Lamiales

Lamiaceae (Labiatae) - the Mint Family

Diversity:  Herbs and shrubs that, like the Apiaceae, shows a center of diversity in the Mediterranean basin and a tendency to produce volatile oils.  Thus, of the ca. 210 genera and ca. 3,500 species, many are used as herbs and spices for cooking.  These include sage (Salvia officinalis), rosemary (Rosmarinus officinalis)), mint (several Mentha species), and many others.

Distribution:  Worldwide, with greatest diversity in north temperate ares, especially southern Europe and the Mediterranean. We have 32 genera and 127 species in the Texas flora, including the endemic genera, Rhododon. and Brazoria.

Floral structure:

Significant features:  This family carries the distinctive gynoecium of the Lamiales in that the ovary usually shows a second septum, producing 4 locules and each of these has only a single seed.  Most mints show a 4-lobed gynoecium and gynobasic style, similar to that of the Boraginaceae. Contrasting with the Boraginaceae, the Lamiaceae usually show a quadrangular stem and opposite leaves.  While sharing corolla zygomorphy with the Verbenaceae, this is usually more pronounced to produce a bilabiate or 'two-lipped' corolla.  Pubescence of most taxa of the Lamiaceae includes glandular trichomes that secrete volitale oils producing the 'minty' smell or taste that is a good key character.  As indicated below, the Lamiaceae also tend to have the flowers positioned as whorls at the nodes.
 
 


Salvia officinalis
- common sage of Europe -
note gynoecium, androecium detail) and photo of inflorescence (right)

common in local woodlands, native: Salvia lyrata

plant
flowers
bee-eye view
mature gynoecium

Monarda citriodora

floral whorls/bracts
flowers - side
flowers - bee-eye view
calyx/corolla

 
Distinctive genera:  Scutellaria - skullcap - (left) calyx with inflated 'cap', and Teucrium - germander - no upper lip for the corolla (right) = 'unilabiate' corolla

More information on the Lamiaceae (or Labiatae)


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