Lamiales

(botany) An order of dicotyledonous plants in the subclass Asteridae marked by its characteristic gynoecium, consisting of usually two biovulate carpels, with each carpel divided between the ovules by a false partition, or with the two halves of the carpel seemingly wholly separate.

An order of flowering plants (Magnoliophyta, or angiosperms), in the subclass Asteridae (Eudicotyledons). The order consists of some 22 families with approximately 1100 genera and over 21,000 species. Seven families (Acanthaceae, Gesneriaceae, Lamiaceae, Orobanchaceae, Plantaginaceae, Scrophulariaceae, Verbenaceae) have more than 1000 species. Members of the Lamiales are distributed worldwide with some families being predominantly tropical and some being predominantly temperate. Lamiaceae, the largest family, is well represented in both tropical and temperate floras.

A basal split in the evolutionary relationships within the order sets off the family Oleaceae, with tetramerous flowers, which are radially symmetric, from the rest of the Lamiales. Pentamerous flowers with fewer stamens (two or four) than petals and bilateral symmetry predominate among the other families. Flowers of all families are characterized by petals fused into a tubular corolla, a single whorl of stamens (typically four), and ovaries consisting of two fused carpels. Iridoid compounds are found in most members of the Lamiales and are thought to function in deterring herbivory by insects. However, iridoids are not universal in the order and, for example, the large subfamily Nepetoideae in family Lamiaceae lacks iridoids but exhibits a diverse array of volatile oils that may serve a similar function.

The volatile oils in the Lamiaceae have made many species valuable as scents and herbs, including lavender (Lavandula), mint (Mentha), sage (Salvia), catnip (Nepeta), basil (Ocimum), and oregano (Oreganum). Additional economically important plants in the Lamiales include those grown for food: sesame (Sesamum, Pedaliaceae) and olives (Olea, Oleaceae); wood: teak (Tectona, Verbenaceae) and ash (Fraxinus, Oleaceae); houseplants: African violets and relatives (Gesneriaceae); and many ornamental plants from a wide variety of families. The order also contains some plants with specialized habits, including parasitic plants (Orobanchaceae), insectivorous plants (Byblidaceae, Lentibulariaceae), mangroves (Avicenniaceae), and aquatic plants, such as Callitriche and Hippuris (Plantaginaceae). See also Asteridae; Magnoliophyta; Magnoliopsida; Plant kingdom.

Lamiales
Galeopsis speciosa
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Lamiales Bromhead
Families
Acanthaceae Bignoniaceae Byblidaceae Calceolariaceae Carlemanniaceae Gesneriaceae Lamiaceae Lentibulariaceae Martyniaceae Oleaceae Orobanchaceae Paulowniaceae Pedaliacae Phrymaceae Plantaginaceae Plocospermataceae Schlegeliaceae Scrophulariaceae Stilbaceae Tetrachondraceae Verbenaceae

The order Lamiales is a taxon in the asterid group of dicotyledonous flowering plants. It includes approximately 11,000 species divided into about 10 families. Well-known or economically important members of this order include lavender, lilac, olive, jasmine, the ash tree, teak, snapdragon, sesame, psyllium, and a number of table herbs such as mint, basil, and rosemary.

Characteristics

Species in this order typically have the following characteristics, although there are exceptions to all of them:

• superior ovary composed of two fused carpels
• five petals fused into a tube
• bilaterally symmetrical, often bilabiate corollas
• four (or fewer) fertile stamens

Taxonomic history

Lamiales formerly had a restricted circumscription (e.g., by Arthur Cronquist) that included the major families Lamiaceae (Labiatae), Verbenaceae, and Boraginaceae plus a few smaller families. Recent phylogenetic work has shown that Lamiales is polyphyletic with respect to order Scrophulariales and the two groups are now usually combined in a single order that also includes the former orders Hippuridales and Plantaginales. Lamiales has become the preferred name for this much larger combined group. The placement of Boraginaceae is unclear but phylogenetic work shows that this family does not belong in Lamiales.

Also, the circumscription of family Scrophulariaceae, formerly a paraphyletic group defined primarily by plesiomorphic characters and from within which numerous other families of the Lamiales were derived, has been radically altered to create a number of smaller, better-defined and putatively monophyletic families.

External links

• Lamiales
• A parsimony analysis of the Asteridae sensu lato based on rbcL sequences
• Distintegration of the Scrophulariaceae (deals with relationships throughout Lamiales)
• http://www.itis.usda.gov of 2002-05-31 TSN: 500018
• L. Watson and M.J. Dallwitz (1992 onwards). The families of flowering plants: descriptions, illustrations, identification, information retrieval. http://delta-intkey.com
• http://www.biologie.uni-hamburg.de/b-online/vascular/acanth.htm 2002-09-06
• http://www.biologie.uni-hamburg.de/b-online/d52/52e.htm 2002-09-06
• http://www.biologie.uni-hamburg.de/b-online/d52/52efam.htm 2002-09-06
• http://www.science.siu.edu/parasitic-plants/Relation-Scroph.html
• http://www.rbgkew.org.uk/web.dbs/genlist.html 2002-09-06

• Media related to Lamiales at Wikimedia Commons
• Information related to Lamiales from Wikispecies.

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