Topics: Flower, Plant sexuality, Pollination Pages: 16 (5129 words) Published: January 10, 2013
Flowering plants (angiosperms) comprise about 90 percent of the Kingdom Plantae. The total number of described species exceeds 250,000, and many tropical species are as yet unnamed. During the past 130 million years, flowering plants have colonized practically every conceivable habitat on earth, from sun-baked deserts and windswept alpine summits to fertile grasslands, freshwater marshes, dense forests and lush mountain meadows. Although a number of flowering plants live in aquatic habitats and have adapted to the saline conditions of dry lake beds and salt marshes, relatively few species live submersed in the oceans. True marine angiosperms are found throughout the oceans of the world, although most species are distributed in tropical regions. They are sometimes referred to as "seagrasses" and include about 50 species in 12 genera. Virtually all flowering plants produce some type of functional floral organ, although in some families such as the Lemnaceae, the flowers are microscopic and are seldom seen by the casual observer. Certain grasses and specialized cultivars apparently do not produce flowers, although they may still have rudimentary flowers (vestigial floral parts). The three largest flowering plant families containing the greatest number of species are the sunflower family (Asteraceae) with about 24,000 species, the orchid family (Orchidaceae) with about 20,000 species, and the legume or pea family (Fabaceae) with 18,000 species. [Judd, W.S. et al. 2008 Plant Systematics: A Phylogenetic Approach lists 23,000 for Asteraceae, 19,500 for Orchidaceae and 18,000 for Fabaceae.] The total number of species for these three enormous families alone is approximately 62,000, roughly 25 percent of all the flowering plant species on earth. To put it another way, if you randomly lined up all the species of flowering plants on earth, every fourth one would be an orchid (Orchidaceae), a sunflower (Asteraceae) or a legume (Fabaceae). The state of California (where Wayne's Word is based) includes about 5,000 native and naturalized species, and 41 percent of these species belong to the following six plant families: sunflower family (Asteraceae), grass family (Poaceae), legume family (Fabaceae), snapdragon family (Scrophulariaceae), mustard family (Brassicaceae), and sedge family (Cyperaceae). The following website in collaboration between the Royal Botanic Gardens, Kew and Missouri Botanical Garden gives a complete working list of all known plant species, including angiosperms (352,000), gymnosperms (1000), pteridophytes (13,000) and bryophytes (20,000). In general, some of the totals are higher than other summeries because they have included a large number of "unresolved" species: Compositae (Asteraceae) = 27,773, Orchidaceae = 27,135 and Leguminosae (Fabaceae) = 23,535. |

The two largest plant families are the sunflower family (Asteraceae) with 24,000 species and the orchid family (Orchidaceae) with about 20,000 species. Left: A vivid red daisy (Gerbera jamesonii) native to the Transvaal region of South Africa. Right: The black orchid (Encyclia cochieatum), national flower of Belize.|

Flower heads of the sunflower family (Asteraceae) come in an astonishing variation of sizes, from minute heads of fleabane (Conyza floribunda) less than 3 mm in diameter (red arrow), to the massive seed-bearing heads of the giant sunflower (Helianthus annus).|

  How Large Is Penny In Above Image  |

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Orchids come in an astonishing variety of shapes, sizes and colors. Left: Odontoglossum schlieperanum native to Costa Rica and Panama. Right: Rhyncholaelia (Brassavola) digbyana also native to Central America.|

One of the many beautiful hybrids of lady's slippers orchids of the genus Paphiopedilum.|

The Enormous Sunflower Family
Details Of An Orchid Blossom|
Some of the largest herbaceous (nonwoody) genera of flowering plants include sedges (Carex: 900), lupines (Lupinus: 300), asters (Aster: 600), onions...
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