-
Introduction
- Southern Illinois University Press
- Chapter
- Additional Information
Introduction All flowering plants may be divided into two great groups, the monocotyledons, or monocots, and the dicotyledons, or dicots. Monocots are plants which produce a single leaf, called a seed leaf, when the seeds first germinate. Dicots, on the other hand, are plants which give rise to a pair of seed leaves when germination occurs. Although monocots are fewer in number than dicots, they include many important groups of plants. Grasses, sedges, lilies, orchids, irises, aroids, and pondweeds are some examples of monocots . The members of this group have been described in five previous volumes in The Illustrated Flora of Illinois. Dicots, which are more numerous in Illinois, include wellknown plants such as roses, peas, mustards, mints, nightshades, milkweeds, and asters. One volume treating dicots has been published previously in this series. Since the time of Linnaeus, and even before, hundreds of attempts have been made to organize the orders and families of plants into a logical sequence, generally trying to place plants which have similar characteristics near each other. As more and more features are studied, aided recently by sophisticated instruments such as the scanning electron microscope, revised systems of classification are developed in an effort to depict a truer picture of relationships. Most contemporary systems of classification have important features . No system can be said to be the best system since the phylogenists creating these systems must make their own value judgments concerning the importance of various characteristics. I have chosen for The Illustrated Flora of Illinois a classification proposed by Robert Thorne in outline form in 1968. Thorne's concepts have been accepted generally in this work, although I have departed from his system in a few instances. I am following Thorne in using the standard suffix -aceae for all families. Thus in this volume, the mustard family, traditionally known as the Cruciferae, becomes the Brassicaceae. Elsewhere in the Illinois flora, the Guttiferae becomes the Hypericaceae, the Leguminosae becomes the Fabaceae, the Umbelliferae becomes the Apiaceae, the Labiatae becomes the Lamiaceae, the Compositae becomes the Asteraceae, and the Gramineae becomes the Poaceae. 2 I WILLOWS TO MUSTARDS Since the Thorne classification is considerably different from the more traditional Engler system, the sequence for the dicots is presented next. Those names in boldface are described in this volume of The Illustrated Flora of Illinois. Order Annonales Family Magnoliaceae Family Annonaceae Family Calycanthaceae Family Aristolochiaceae Family Lauraceae Family Saururaceae Order Berberidales Family Menispermaceae Family Ranunculaceae Family Berberidaceae Family Papaveraceae Order Nymphaeales Family Nymphaeaceae Family Ceratophyllaceae Order Sarraceniales Family Sarraceniaceae Order Theales Family Aquifoliaceae Family Hypericaceae1 Family Elatinaceae Family Ericaceae Order Ebenales Family Ebenaceae Family Styracaceae Family Sapotaceae Order Primulales Family Primulaceae Order Cistales Family Violaceae Family Cistaceae Family PassiHoraceae Family Cucurbitaceae Family Loasaceae Order Salicales Family Salicaceae lCalled Clusiaceae by Thome (1968). Order Tamaricales Family Tamaricaceae Order Capparidales Family Capparidaceae Family Resedaceae Family Brassicaceae Order Malvales Family Sterculiaceae Family Tiliaceae Family Malvaceae Order Urticales Family Ulmaceae Family Moraceae Family Urticaceae Order Rhamnales Family Rhamnaceae Family Elaeagnaceae Order Euphorbiales Family Euphorbiaceae Order Solanales Family Solanaceae Family Convolvulaceae Family Polemoniaceae Order Campanulales Family Campanulaceae Order Santalales Family Celastraceae Family Santalaceae Family Loranthaceae Order Oleales Family Oleaceae Order Geraniales Family Linaceae Family Zygophyllaceae Family Oxalidaceae Family Geraniaceae [54.234.143.240] Project MUSE (2024-03-29 06:27 GMT) Family Balsaminaceae Family Limnanthaceae Family Polygalaceae Order Rutales Family Rutaceae Family Simaroubaceae Family Anacardiaceae Family Sapindaceae Family Aceraceae Family Hippocastanaceae Family Juglandaceae Order Myricales Family Myricaceae Order Chenopodiales Family Phytolaccaceae Family Nyctaginaceae Family Aizoaceae Family Cactaceae Family Portulacaceae Family Chenopodiaceae Family Amaranthaceae Family Caryophyllaceae Family Polygonaceae Order Hamamelidales Family Hamamelidaceae Family Platanaceae Order Fagales Family Fagaceae Family Betulaceae Order Rosales Family Rosaceae Family Fabaceae Family Crassulaceae Family Saxifragaceae Family Droseraceae Family Staphyleaceae Order Myrtales Family Lythraceae Family Melastomaceae Introduction / 3 Family Onagraceae Order Gentianales Family Loganiaceae Family Rubiaceae Family Apocynaceae Family Asclepiadaceae2 Family Gentianaceae Family Menyanthaceae Order Bignoniales Family Bignoniaceae Family Martyniaceae Family Scrophulariaceae Family Plantaginaceae Family Orobanchaceae Family Lentibulariaceae Family Acanthaceae Order Comales Family Vitaceae Family Nyssaceae Family Comaceae Family Haloragidaceae Family Hippuridaceae Family Araliaceae Family Apiaceae3 Order Dipsacales Family Caprifoliaceae Family Adoxaceae Family Valerianaceae Family Dipsacaceae Order Lamiales Family Hydrophyllaceae Family Boraginaceae Family Verbenaceae Family Phrymataceae4 Family Callitrichaceae Family Lamiaceae Order Asterales Family Asteraceae 2Included in Apocynaceae by Thome (1g68). 3Included in Araliaceae by Thome (1968). 4Included in Verbenaceae by Thome (1g68). 4 I WILLOWS TO MUSTARDS Three orders of vascular plants are included in this volume, encompassing five families. Because such a small number of families of dicots is...