Species of the family generally haveflowers that divide into four or five parts, usually with strong scents. They range in form and size fromherbs toshrubs and large[5]trees.
The most economically importantgenus in the family isCitrus, which includes theorange (C. ×sinensis),lemon (C. ×limon),grapefruit (C. ×paradisi), andlime (various).Boronia is a large Australian genus, some members of which are plants with highly fragrant flowers and are used in commercialoil production. Other large genera includeZanthoxylum, several species of which are cultivated forSichuan pepper,Melicope, andAgathosma. Thefamily Rutaceae contains about 160genera.
Most species are trees or shrubs, a few are herbs (the type genusRuta,Boenninghausenia, andDictamnus), frequently aromatic withglands on theleaves, sometimes withthorns. The leaves are usually opposed andcompound and withoutstipules. Pellucid glands, a type of oil gland, are found in the leaves responsible for the aromatic smell of the family's members; traditionally they have been the primarysynapomorphic characteristic to identify the Rutaceae.[citation needed]
Flowers arebractless, solitary or incyme, rarely inraceme, and mainlypollinated by insects. They areradially or (rarely) laterally symmetric and generallyhermaphroditic. They have four or five—sometimes three—mostly separatepetals andsepals and eight to tenstamen (five inSkimmia, many inCitrus), usually separate or in several groups. Usually they have only a single stigma with 2 to 5 unitedcarpels. Their ovaries are sometimes separate, but their styles are combined.[citation needed]
In 1896, Engler published a division of the family Rutaceae into seven subfamilies.[6] One, Rhabdodendroideae, is no longer considered to belong to the Rutaceae, being treated as the segregate family Rhabdodendraceae, containing only the genusRhabdodendron. Two monogeneric subfamilies, Dictyolomatoideae and Spathelioideae, are now included in the subfamilyCneoroideae, along with genera Engler placed in other families. The remaining four Engler subfamilies wereAurantioideae,Rutoideae, Flindersioideae and Toddalioideae. Engler's division into subfamilies largely relied on the characteristics of the fruit, as did others used untilmolecular phylogenetic methods were applied.[7]
Molecular methods have shown that only Aurantioideae can be clearly differentiated from other members of the family based on fruit. They have not supported thecircumscriptions of Engler's three other main subfamilies.[7] In 2012, Groppo et al. divided Rutaceae into only two subfamilies, retaining Cneoroideae but placing all the remaining genera in a greatly enlarged subfamily Rutoideaes.l.[2] A 2014 classification by Morton and Telmer also retained Engler's Aurantioideae, but split the remaining Rutoideaes.l. into a smaller Rutoideae and a much larger Amyridoideaes.l., containing most of Engler's Rutoideae.[8] Until 2021, molecular phylogenetic methods had only sampled between 20% and 40% of the genera of Rutaceae. A 2021 study by Appelhans et al. sampled almost 90% of the genera. The two mainclades recognized by Groppo et al. in 2012 were upheld, but Morton and Telmer's Rutoideae wasparaphyletic and their Amyridoideae waspolyphyletic and did not include the type genus. Applehans et al. divided the family into six subfamilies, shown below in thecladogram produced in their study. The large subfamilyZanthoxyloideae was shown to contain distinct clades, but the authors considered that a revised classification at the tribal level was not yet feasible at the time their paper was published.[7]
The genusPilocarpus has species (P. jaborandi, andP. microphyllus from Brazil, andP. pennatifolius from Paraguay) from which the medicinepilocarpine, used to treat glaucoma, is extracted.
^abcGroppo, M.; Kallunki, J.A.; Pirani, J.R. & Antonelli, A. (2012). "ChileanPitavia more closely related to Oceania and Old World Rutaceae than to Neotropical groups: Evidence from two cpDNA non-coding regions, with a new subfamilial classification of the family".PhytoKeys (19):9–29.doi:10.3897/phytokeys.19.3912.PMC3597001.PMID23717188.
^RUTACEAE in BoDD – Botanical Dermatology Database
^Engler, A. (1896). "Rutaceae". In Engler, A. & Prantl, K. (eds.).Die natürlichen Pflanzenfamilien. Vol. III(4). Leipzig: Engelmann.
^abcAppelhans, Marc S.; Bayly, Michael J.; Heslewood, Margaret M.; Groppo, Milton; Verboom, G. Anthony; Forster, Paul I.; Kallunki, Jacquelyn A. & Duretto, Marco F. (2021). "A new subfamily classification of theCitrus family (Rutaceae) based on six nuclear and plastid markers".Taxon.70 (5):1035–1061.doi:10.1002/tax.12543.hdl:11343/288824.
