Angiosperms
The angiosperms, or flowering plants (division Anthophyta or Magnoliophyta), comprise more than 230,000 species and are thus by far the largest division of plants; they represent the dominant group of land plants today. In both vegetative and floral morphology the angiosperms are highly diverse. In size, for example, they range from the duckweeds (the genus Lemna), which are roughly one millimeter in length, to Eucalyptus trees, which are well over one hundred meters. Although all are characterized by the possession of flowers, these structures are also highly diverse in form and size. The smallest flowers are less than a millimeter in size (the flowers of duckweeds) while the largest flowers are approximately one meter in diameter (the flowers of Rafflesia). Features unique, or nearly so, to angiosperms include the flower; the presence of seeds within a closed structure (actually a modified leaf) referred to as the carpel; the reduction of the female gametophyte to eight nuclei and seven cells; double fertilization (the
| MAJOR ANGIOSPERM GROUPS | | |
| Major Clades and Representative Families | Common Name | Number of Species in Family (approximate) |
| Eurosid | | |
| Rosaceae | Rose family | 3,500 |
| Fabaceae | Pea or legume family | 17,000 |
| Brassicaceae | Mustard family | 3,000 |
| Fagaceae | Beech or oak family | 1,000 |
| Cucurbitaceae | Pumpkin or gourd family | 700 |
| Euphorbiaceae | Spurge family | 5,000 |
| Juglandaceae | Walnut or hickory family | 50 |
| Begoniacae | Begonia family | 1,000 |
| Geraniaceae | Geranium family | 750 |
| Malvaceae | Cotton family | 1,000 |
| Euasterid | | |
| Cornaceae | Dogwood family | 100 |
| Ericaceae | Heath family | 3,000 |
| Lamiaceae | Mint family | 3,000 |
| Solanaceae | Tomato or potato family | 2,500 |
| Asteraceae | Sunflower family | 25,000 |
| Apiaceae | Parsley family | 3,000 |
| Hydrangeaceae | Hydrangea family | 170 |
| Caryophyllales | | |
| Cactaceae | Cactus family | 2,000 |
| Caryophyllaceae | Carnation or pink family | 2,000 |
| Aizoaceae | Mesembryanthemum family | 2,300 |
| Portulacaceae | Portulaca family | 500 |
| Polygonaceae | Buckwheat or rhubarb family | 750 |
| Magnoliids* | | |
| Magnoliaceae | Magnolia family | 200 |
| Lauraceae | Avocado or cinnamon family | 2,500 |
| Piperaceae | Pepper family | 3,000 |
| Myristicaceae | Nutmeg family | 380 |
| Annonaceae | Sweetsop family | 2,000 |
| Monocots* | | |
| Orchidaceae | Orchid family | 18,000 |
| Poaceae | Grass family | 9,000 |
| Arecaceae | Palm family | 2,800 |
| Araceae | Arum family | 2,000 |
| * Indicates major clades that are noneudicots; other major clades are eudicots. |
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Angiosperms from Macmillan Science Library: Plant Sciences. Copyright © 2001-2006 by Macmillan Reference USA, an imprint of the Gale Group. All rights reserved.
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