Rutaceae

Rutaceae
Skimmia japonica
Scientific classification
Kingdom: Plantae (unranked): Angiosperms (unranked): Eudicots (unranked): Rosids Order: Sapindales Family: Rutaceae Juss., 1789
Diversity
About 160 genera, totaling over 1600 species.
Subfamilies
Aurantioideae Flindersioideae Rutoideae Spathelioideae Toddalioideae[1]

Rutaceae, commonly known as the rue^[2] or citrus family^[3], is a family of plants, usually placed in the order Sapindales.

Species of the family generally have flowers that divide into four or five parts, usually with strong scents. They range in form and size from herbs to shrubs and small trees.

The most economically important genus in the family is Citrus, which includes the orange (C. sinensis), lemon (C. × limon), grapefruit (C. paradisi), and lime (various, mostly C. aurantifolia, the key lime). Boronia is a large Australian genus, some members of which are plants with highly fragrant flowers and are used in commercial oil production. Other large genera include Zanthoxylum and Agathosma.

Characteristics

Most species are trees or shrubs, a few are herbs (Boenninghausenia), frequently aromatic with glands on the leaves, sometimes with thorns. The leaves are usually opposed and compound, and without stipules. On the leaves can be found pellucid glands which are responsible for the aromatic smell of the members of Rutaceae.

Flowers are bractless, solitary or in cyme, rarely in raceme, and mainly pollinated by insects. They are radially or (rarely) laterally symmetric, and generally hermaphroditic. They have four or five petals and sepals, sometimes three, mostly separate, eight to ten stamen (five in Skimmia, many in Citrus), usually separate on in several groups. Usually a single stigma with 2 to 5 united carpels, sometimes ovaries separate and styles combined.

The fruit of Rutaceae are very variable: berries, drupes, hesperidiums, samara, capsules and follicles all occur. Seed number also varies widely.

Classification

The family is closely related to Sapindaceae, Simaroubaceae and Meliaceae, and all are usually placed into the same order, although some systems separate that order into Rutales and Sapindales. The families Flindersiaceae and Ptaeroxylaceae are sometimes kept separate, but nowadays generally placed in Rutaceae, as are the former Cneoraceae. The subfamilial organization has not been fully resolved, but the subfamilies Citroideae (=Aurantioideae) and Rutoideae are well supported; the placement of several genera remains unclear.

Notable species

various Citrus fruits

The family is of great economic importance under tropical climates for its numerous edible fruits of the Citrus genus, such as the orange, lemon, lime, kumquat, mandarine and grapefruit. Non-citrus fruits include the White sapote (Casimiroa edulis) and the bael (Aegle marmelos). Other plants are grown in horticulture: Murraya species, for example. Ruta, Zanthoxylum and Casimiroa species are medicinals. Several plants are also used by the perfume industry, such as the Western Australian Boronia megastigma.

References

• Singh, Gurjaran (2004). Plant Systematics: An Integrated Approach. Enfield, New Hampshire: Science Publishers. pp. 438–440. ISBN 1-57808-342-7. 
• Chase, Mark W.; Cynthia M. Morton & Jacquelyn A. Kallunki (August 1999). "Phylogenetic relationships of Rutaceae: a cladistic analysis of the subfamilies using evidence from RBC and ATP sequence variation". American Journal of Botany 86 (8): 1191–1199. doi:10.2307/2656983. PMID 10449399. http://www.amjbot.org/cgi/content/full/86/8/1191. Retrieved 2007-08-30. 

External links

• Media related to Rutaceae at Wikimedia Commons