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PBIO 250 Lecture Notes

James L. Reveal

Norton-Brown Herbarium, University of Maryland


Selected Families of Angiosperms: Rosidae

ROSIDAE Takht., 1967: 18 order, 116 families and more than 60,000 species; this is the largest subclass of angiosperms in terms of families and about the same size as Asteridae in the number of species (as defined by Cronquist). The majority of orders hang together, being more advanced than the Magnoliidae and less so than the Asteridae. The stamens, when numerous, are usually initiated in a centripetal sequence, the flowers seldom have parietal placentation and rarely are they free-central or unilocular and basal. In those species with few stamens, the syncarpous ovaries are 2-several loculed but with only 1-2 ovules per locule. The flowers are usually polypetalous, rarely sympetalous; occasionally apetalous.Bremer et al. place the lower hamamelids (as Saxifragales) and the whole of the Caryophyllidae in thier "core eudicots" group while the upper hamamelids and the dillenids are assigned to their "rosids" group. Their "rosoids" group is subdivided into two subgroupings, the "eurosids I" (Oxalidales, Rosales, Fabales, Cucurbitales, Malpighiales, etc.) and "eurosids II" (Myrtales and Sapindales). Groups otherwise assigned to the Dilleniidae are other wise scattered in the two subgroups. Excluded from both subgroups are the Geraniales. Summary from the University of Wisconsin.

Rosales Perleb, 1826 - see also this summary

Grossulariaceae DC., 1805: Shrubs or trees (as defined by Cronquist), often spiny, with simple and often deeply lobed leaves, 5-merous flowers, a petaloid calyx and an inferior ovary. CA(4-5 CO5 A5 GI(2-3). 25 genera, 320 species. Frequently cultivated as decorative shrubs; the source of currant and gooseberry jams and jellies. Note: Except for Cronquist, all other workers defines this family to consist of a single genus, Ribes (150, mainly northern hemisphere and the Andeas). The other genera are referred to the Argophyllaceae (Engl.) Takht., Brexiaceae Loud., Escalloniaceae R. Br. ex Dumort., Iteaceae J. Agardh (Itea), Montiniaceae Nakai, Phyllonomaceae Small (including Dulongiaceae J. Agardh, nom. illeg.), Pterostemonaceae Small, Tetracarpaeaceae Nakai and Tribelaceae (Engl.) Airy Shaw. Essentially all of these families are unrelated to the Rosales. A few are better placed in the Saxifragales and while well removed from the true rosoid families they are still a part of the Rosidae. The majority, however, are not even members of the Rosidae, being more properly assigned to the Cornidae and positioned near the Hydrangeaceae Dumort. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopses from the University of Hawaii and Utah State.

Crassulaceae DC., 1805: Succulent herbs or subshrubs with astipulate leaves, 4- or 5-merous flowers and carpels the same number as the petals. CA4-5 CO4-5 A8-10 GS4-5. 37 genera, 1280 species. Widespread except for Australia. Many cultivated succulents belong to this family: Crassula, Echeveria, Kalanchoe, Sedum, Sempervivum and Villadia. Many occur in arid regions. The genus Sedum (more than 300 species) is now being divided into several genera. Better placed in the Crassulales just basal to Saxifragales. The family is divided into three subfamilies: Sempervivoideae (Durande) Arn. (including Sedoideae Endl. ex Walp.), Kalanchoideae (including Cotyledonoideae) and Crassuloideae Burnett. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopses from the University of Hawaii and Utah State.

Saxifragaceae Juss., 1789: Perennial herbs with alternate astipulate leaves and perigynous 5-merous flowers. CA5 CO5 A5 or 10 GS(2-5). 40 genera, 700 species as defined by Cronquist; in the strict sense now adopted by essentially all workers a family of 31 genera and some 650 species. Essentially all are herbaceous perennials. Several cultivated. More than half of the genera are monospecific. Numerous additional families are now recognized: Eremosynaceae Dandy, Francoaceae A. Juss., Lepuropetalaceae (Engl.) Nakai, Parnassiaceae Gray, Penthoraceae Rydb. ex Britt. and Vahliaceae Dandy. Eremosynaceae and Vahliaceae belong to the Hydrangeales in Cornideae; Francoaceae in its own order basal to Saxifragales; Lepuropetalaceae and Parnassiaceae belong to the Parnassiales in the Celastranae, not the Saxifraganae; and Penthoraceae is now better placed near Crassulaceae in the Crassulales. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family snyopses from the University of Hawaii and Utah State. See also Cardillo & Samuels.

Rosaceae Juss., 1789: Herbs, shrubs or trees with stipulate leaves, actinomorphic flowers with 5 sepals and petals, and numerous stamens typically with a hypanthium. CA(5 CO(5-many GS1 or GS-many, or GI(5). 96 genera, 3100 species. Cosmopolitan, but mainly temperate and warm regions. Several plants of major economic importance, especially the maloids (apples, pears, apricots, etc.). The family is now divided into five subfamilies: Neilleioideae Arn., Spiraeoideae (Juss.) Arn., Rosoideae (Juss.) Arn., Amygdaloideae (Juss.) Arn. (including Prunoideae Horan.) and Pyroideae Burnett (including Maloideae). Takhtajan (1997) fragments the family into 12 subfamilies. Of these, Aphaneoideae Raf. has priority over Potentilloideae (Juss.) Sweet and Sanguisorboideae (Bercht. & J. Presl) Sweet. The Quillejoideae (D. Don) Arn. are now excluded from the Rosaceae and placed in their own family, the Quillejaceae D. Don. Bremer et al. place the family in their Fabales, but this is highly dubious. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopses from the University of Hawaii and Utah State. See also Cardillo & Samuels.

Fabales Bromhead, 1838

Mimosaceae R. Br., 1814: Trees, shrubs or herbs with bipinnately compound leaves, actinomorphic, 5-merous flowers bearing 10 to many stamens with often brightly colored filaments. CA5 CO5 A5-many GS1. 66 genera, 3000 species. Warm and tropical regions of the world. Many cultivated trees and shrubs; several important ecologically in arid regions of the world (e.g., Acacia, Parkia, Prosopis, etc.). Defined by the regular flowers, bipinnate or less often pinnate or phyllodic leaves. Typically divided into five tribes: Parkieae (Wight & Arn.) Endl., Mimozygantheae, Mimoseae Bronn, Acacieae Dumort. and Ingeae Benth. & Hook.f. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopsis from the University of Hawaii.

Caesalpiniaceae R. Br., 1814: Trees, shrubs or rarely herbs with more or less zygomorphic flowers with a standard and two lateral wings, and 10 stamens. CA5 COz5 A10 GS1. 156 genera, 2700 species. Mainly of temperate and tropical regions. Many cultivated trees, shrubs and herbs; some used for timber. The tallest tropical tree belongs to the genus Koompassia (84 m). Some are medicinals. The family is divided typically into five tribes: Caesalpinieae (R. Br.) Wight & Arn., Cassieae Bronn, Cercideae Bronn, Detarieae DC. and Amherstieae Benth. Some authors refer the Swartzieae DC. to this family while others place it in the Fabaceae. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopsis from the University of Hawaii.

Fabaceae Lindl., 1836 - also known by the alternative name Papilionaceae Giseke; if combined with Mimosaceae and Caesalpiniaceae, the alternative name is Leguminosae Juss.: Trees, shrubs or herbs with pinnately or palmately compound or simple leaves with papilionaceous flowers bearing 10 stamens. CA5 COz(2+2+1)A[9+1 GS1. 455 genera, 12,800 species. Cosmopolitan. Many cultivated especially a crop plants (e.g., Medicago, pea, bean). Mimosaceae and Caesalpiniaceae are often included in Fabaceae and each distinguished as a subfamily, Caesalpinoideae DC., Mimosoideae (R. Br.) DC. and Faboideae (alternative name Papilionoideae L. ex DC.). A fourth subfamily, Swartzioideae DC., is occasionally recognized. Numerous tribes are recognized in the Fabaceae and ongoing research is suggesting more be added. Significantly, the tribe Fabeae Rchb. ex Kitt. has priority over the oft used Vicieae DC. as mandated by the International Code of Botanical Nomenclature. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopses from the University of Hawaii and Utah State. See also Cardillo & Samuels.

Myrtales Rchb., 1828

Onagraceae Juss., 1789: Herbs with 4-merous, rarely 2-merous flowers with a hypanthium and an inferior ovary. [CA4 CO4 A4 or 8] GI(4). 18 genera, 675 species. Widespread but especially in the New World. Cultivated ornamentals include species of Camissonia, Clarkia, Epilobium, Fuchsia, Gaura, Lopezia, Ludwigia, and Oenothera. Divided into five tribes: Lopezieae Spach, Circaeeae Bercht. & J. Presl, Onagreae Bercht. & J. Presl, Jussiaeeae Dumort. and Epilobieae Endl. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopses from the University of Hawaii and Utah State.

Cornales Dumort., 1829

Cornaceae Dumort., 1829: Trees, shrubs or rarely perennial herbs with opposite or alternate leaves, 4- or 5-merous flowers with the stamens altenating with the petals, with an inferior ovary producing a drupe or berry. CA(4-5) CO(4-5) A4-5 GI(2). 15 genera, 120 species. Cosmopolitan. Numerous species are cultivated. Cronquist also included the genus Nyssa ("tupelo") in his broad circumscription of the family, a timber tree. This view is now broadly rejected by current workers with the following families recognized as distinct: Aralidiaceae Philipson & B.C. Stone, Aucubaceae J. Agardh, Curtisiaceae (Harms) Takht., Griseliniaceae J.R. Forst. & G. Forst. ex A. Cunn., Helwingiaceae Decne., Mastixiaceae Calest., Melanophyllaceae Takht. ex Airy Shaw, Nyssaceae Juss. ex Dumort. and Torricellaceae (Wang.) Hu. In a strict sense, Cornaceae consists of two genera, most notably Cornus. The majority of tahe group are better placed in the subclass, Cornidae, and defined to include not only Cronquist's Cornaceae but his Hydrangeaceae (Rosales) as well. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopsis from the University of Hawaii and Utah State.

Celastrales Baskerville, 1839

Aquifoliaceae Bartl., 1830: Deciduous or evergreen trees or shrubs with alternate, simple, sometimes spiny leaves, mostly inconspicuous bisexual or unisexual greenish-white flowers with a 3-locular ovary developing into a berry with 4 pyrenes. CA4 CO4 or (4 A4 GS(4). 4 genera, 400 species. Cosmopolitan. Ilex (400, holly) is commonly cultivated. Nemopanthus is native to eastern North America. Phelline is better placed in the Phellinaceae (Loes.) Takht.and Sphenostemon in Sphenostemonaceae P. Royen & Airy Shaw. All of these family often placed in their own order, Aquifoliales Senft, and positioned near the base of the Rosidae in Celastranae. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopsis from the University of Hawaii.

Euphorbiales Lindl., 1833 - see also this summary

Euphorbiaceae Juss., 1789: Herbs, shrubs or trees often with milky sap, alternate leaves and unisexual flowers bearing a superior, usually trilocular ovary. "Euphorbia-type" flowers: CA0 CO0 A1 G0 and CA0 CO0 A0 GS(3); "non-Euphorbia-type" flowers: CA0 or 5 CO0 or 5 A1-many G0 and CA0 or 5 CO0 or 5 A0 GS(3). 360 genera, 7750 species. Cosmopolitan. Many cultivated as ornamentals (Croton, Poinsettia). Hevea is the source of rubber. Cassava and tapioca comes from Manihot. Several are used for timber and some (Ricinus, castor oil) are poisonous or valuable as medicinals. Several are weedy. Members of the family in Africa often look like members of Cactaceae. Some African members of the family resemble the Cactaceae in their growth form. A recent paper by Meeuse (1990) proposed that the family be divided into nine families, the largest being Euphorbiaceae with more than 7000 species. The others are Androstachyaceae Airy Shaw, Bischofiaceae (Müll.-Arg.) Airy Shaw, Hymenocardiaceae Airy Shaw, Peraceae Klotzsch, Picrodendraceae Small ex Britt. & Millsp. (including Paivaeusaceae A. Meeuse), Stilaginaceae C. Agardh and Uapacaceae (Müll.-Arg.) Airy Shaw. The segregate family Phyllanthaceae Martynov occurs in our area and the Pandaceae, adopated by Cronquist, is sometimes included in the Euphorbiaceae (e.g., Thorne). The family Euphorbiaceae is now generally considered a member of the Dilleniidae in their own superorder near to and basal of the Violanae. No modern worker has adopted the several families recognized by Airy Shaw and Meeuse. This large family is divided into five subfamilies: Phyllanthoideae Kostel., Oldfieldioideae Eg. Köhler & G.L. Webster ex G.L. Webster, Acalyphoideae Kostel., Ricinoideae Kostel. (including Crotonoideae Burmeist.) and Euphorbioideae Burnett. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopses from the University of Hawaii and Utah State. Figures of Euphorbia-type and non-Euphorbia-type

Rhamnales Dumort., 1829

Vitaceae Juss., 1789: Woody, climbing plants with tendrils and an inflorescence arising opposite the leaves harboring small flowers producing a berry. CA(4-5) CO4-5 A4-5 GS(2). 14 genera, 735 species. Mainly tropical and subtropical regions. Grapes and currents come from species of Vitis, the source of wine. The spelling Vitaceae is conserved over "Vitidaceae." Some genera are cultivated. Parthenocissus quinquefolia is a weed throughout much of Europe. The family is now removed from the Rhamnales (in the Rhamnanae) and placed in the Vitales (in the Vitanae). Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopses from the University of Hawaii and Utah State.

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Last revised: 25 Jan 1999
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Selected Families of Angiosperms: Asteridae
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