Rutaceae
Read about Rutaceae in the Standard Cyclopedia of Horticulture
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Rutaceae (from the genus Ruta, the ancient name). Rue Family. Fig. 30. Herbs, rarely shrubby: leaves usually alternate, simple or variously cut or compound, usually with pellucid dots: flowers bisexual, usually regular; sepals 4-5, often coherent, imbricated; petals 4-5, imbricated or valvate, usually separate; stamens 8-10, rarely 15, inserted at the base of a thick disk, usually distinct; ovary superior, 2-5-lobed, 2-5-celled; each cell 1 to many-ovuled, raised on a prolongation of the receptacle, a glandular disk at its base; styles usually connate: fruit a capsule opening by valves, or fleshy and indehiscent, or separating into fruitlets, rarely winged. Rutaceae contains over 100 genera and about 900 species, mostly of tropical countries but extending into temperate parts of Europe and America. Fagara, with more than 130 species, is the largest genus. The Rutaceae are related to many of the Geranium group, especially to Simarubaceae, Zygophyllaceae, and Meliaceae. The transparent dots in the leaves, the numerical plan, and especially the lobed ovary raised on the disk or stalk, are together distinctive. The disk is often much developed and very diversely constructed. The outer stamens are usually opposite the petals, not alternate with them as might be expected. In some cases the carpels are entirely free below and united only by the styles or stigmas. The seeds, except in the berry fruits, are only 1 or 2. The great development of oil-glands containing a fragrant oil is one of the most characteristic features of the family. These glands are produced on all parts of the plant, even on the floral parts and surface of the fruits. The orange and lemon are examples of Rutaceae with berry fruits, and they are widely cultivated and perplexingly variable. The volatile oil of the Rutaceae has been used to some extent for medicine and also for perfumery. Extract of rue has been used as a vermifuge. The Romans used rue as a condiment. Some species of rue are so pungent as to produce a poisoning of the skin similar to that produced by poison ivy. The volatile oil is so copious in Dictamnus as to ignite readily. Several species of Barosma (buchu) are tonic and diuretic. The genus Citrus is the most useful. It includes the orange, the bitter orange, the citron, the lemon, the lime, the grape-fruit, the kid-glove orange or tangerine, and the bergamot from the rind of which bergamot oil is manufactured, used in perfumery. The bark of the prickly shrub, Zanthoxylum, is sometimes used as a tonic. The seeds of some species of Zanthoxylum are used to poison fish. In cultivation in America or worthy of trial are 20 to 30 genera, used mostly for ornament and fruit. Among these are: Adenandra (Breath of Heaven); Aegle (Bael Fruit, Bengal Quince); Atalantia; Balsamocitrus (African Bael-Fruit); Calodendron (Cape Chestnut) ; Casimiroa (White Sapota) ; Citrus (Orange, Lemon); Dictamnus (Dittany, Gas Plant, Burning Bush) ; Fagara (Prickly Ash) ; Feronia (Wood Apple) ; Murraya (Orange Jessamine, Satinwood); Phellodendron (Chinese Cork Tree); Poncirus (Trifoliate Orange); Ptelea (Hop Tree); Ruta (Rue); Triphasia (Bergamot Lime, Lime Berry) ; Zanthoxylum (Prickly-Ash, Chinese or Japanese Pepperwood, Toothache Tree).
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| About 160, totaling over 1600 species. See List of Rutaceae genera |
Rutaceae, commonly known as the Rue or Citrus family, 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.
Flowers are bractless, solitary or in cyme, rarely in raceme, and mainly pollinated by insects. They are radially or (rarely) laterally symmetric, and generally hermaphrodite. 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 are also included. 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
The family is of great economic importance under tropical climates for its numerous edible fruits of the Citrus genus, such as the orange, 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. 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. http://www.amjbot.org/cgi/content/full/86/8/1191. Retrieved 2007-08-30.
