Flowering Plants: Nightshades to Mistletoe

Introduction

Introduction Plants that produce flowers are divided into two groups, the dicotyledons and the monocotyledons. Dicotyledons, or dicots, form two "seed leaves," or cotyledons, when the seed germinates. Monocotyledons, or monocots, form only a single "seed leaf." In the world, as in Illinois, dicots exceed the monocots in number of species . This is the sixth volume ofThe Illustrated Flora oflllinois that includes dicots. Five volumes on monocots and one each on ferns and diatoms have also been published in this series. For The Illustrated Flora of Illinois, I have used a modified version of the Thorne system of classification (1g68). Thorne's system, utilizing information gathered from cytology, biochemistry, anatomy , and embryology, more clearly depicts natural relationships among flowering plants than does the more familiar Engler and Prantl system used in most floras. Since the arrangement of orders and families of flowering plants proposed by Thorne is unfamiliar to many, an outline of the orders and families of flowering plants known to occur in Illinois is presented . Those groups 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 Passifloraceae 2 I NIGHTSHADES TO MISTLETOE Family Cucurbitaceae Family Loasaceae Order Salicales Family Salicaceae 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 Rbamnales Family Rbamnaceae Family Elaeagnaceae Order Euphorbiales Family Thymelaeaceae Family Euphorbiaceae Order Solanales Family Solanaceae Family Convolvulaceae Family Cuscutaceae2 Family Polemoniaceae Order Campanulales Family Campanulaceae Order Santalales Family Celastraceae Family Santalaceae Family Viscaceae Order Oleales Family Oleaceae Order Geraniales Family Linaceae Family Zygophyllaceae Family Oxalidaceae Family Geraniaceae 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 Family Corylaceae Order Rosales Family Rosaceae Family Fabaceae Family Crassulaceae Family Saxifragaceae Family Droseraceae Family Staphyleaceae Order Myrtales Family Lythraceae Family Melastomaceae Family Onagraceae Order Gentianales Family Loganiaceae Family Rubiaceae Family Apocynaceae Family Asclepiadaceae3 Family Gentianaceae Family Menyanthaceae Order Bignoniales Family Bignoniaceae Family Martyniaceae Family Scrophulariaceae Familyo Plantaginaceae Family Orobanchaceae Family Lentibulariaceae Family Acanthaceae Order Cornales Family Vitaceae Family Nyssaceae Family Cornaceae Family Haloragidaceae Family Hippuridaceae 1Called Clusiaceae by Thorne (1g68). Family Araliaceae Family Apiaceae4 Introduction I 3 Order Dipsacales Family Caprifoliaceae Family Adoxaceae Family Valerianaceae Family Dipsacaceae Order Lamiales Family Hydrophyllaceae Family Boraginaceae Family Verbenaceae Family Phrymataceae5 Family Callitrichaceae Family Lamiaceae Order Asterales Family Asteraceae 2Included in Convolvulaceae by Thorne (1g68). 'Included in Apocynaceae by Thorne (1g68). 'Included in Araliaceae by Thorne (1g68). 'Included in Verbenaceae by Thorne (1g68). Included in this volume are the orders Solanales, with four families , Campanulales, with one family, and Santalales, with three families. Since only a small number of dicot families are treated in this book, no general key to the dicot families has been provided. The reader is invited to use my companion book, Guide to the Vascular Flora of Illinois. Revised and Enlarged Edition (1g86), for keys to all families of flowering plants in Illinois. Families that are included in the Solanales usually have alternate leaves, actinomorphic flowers, united petals, five stamens, and a superior ovary that is not four-parted. The Lamiales, similar by their united petals, usually have zygomorphic flowers and a fourparted ovary. The Gentianales, also similar by their united petals, usually have opposite leaves. Both the Lamiales and Gentianales will be treated in subsequent volumes of The Illustrated Flora of Illinois. The families of Solanales represented in Illinois and included in this book are the Solanaceae, Convolvulaceae, Cuscutaceae , and Polemoniaceae. The order Campanulales, consisting of only the family Campanulaceae , have alternate leaves, united petals, and five stamens, but 4 I NIGHTSHADES TO MISTLETOE differ from the Solanales by their inferior ovary. Some of them also have zygomorphic flowers. The order Santalales, at first glance in Illinois, seem to include three very unrelated...