Angiosperms and Gymnosperms By Amanda Bradshaw BIOL 1411.003 April 20, 2002
Angiosperms • Angiosperms are flowering plants. • The term angiosperm comes from Greek: angeion meaning vessel and sperma meaning seed.
Angiosperms make up the dominant form of plant life. • They serve as the main food source for humans and other mammals. • Also, many of the raw materials and natural products that we use today come from angiosperms.
The distinguishing feature of the angiosperm is the flower. • The flower serves as the reproductive system of the plant. • The flower carries out seed development and fruit production.
Parts of flowering plants • The main axis of the flower is called the peduncle. • The individual stalk of the flower is the pedicel. • The receptacle is the portion of the plant where all the flower parts attach.
The parts of the flower • The flower consists of four main parts in a series of whorls. • The first part is the sepal and it is usually green. Calyx is the collective term for sepals. • The second part is the petal, the colorful part of the flower. Corolla is the collective term for petals.
More flower parts • The third part of the flower is the stamen or the male portion of the plant. The stamen contains the anther, which produces pollen grains, and the filament, which supports the anther. • The fourth part of the flower is the pistil or the female portion of the plant.
The pistil • The pistil is made up of the: • Stigma, the upper portion which receives pollen. • Style which serves as the pathway for the pollen tube. • Ovary which produces ovules that will later turn into seeds. The ovary will eventually become fruit.
The entire stalk of flowers is called the inflorescence. • A flower can be staminate, meaning that it has only stamens present. • A flower can be pistillate, meaning that only the pistil is present.
Categories of flowers • Complete flowers contain sepal, petal, stamen, and pistil. • Incomplete flowers lack one or more of the four organs. • Perfect flowers contain stamens and pistils on the same flower.
Categories continued • Imperfect flowers have stamens and pistils on separate flowers. • Dioecious meaning staminate and pistillate flowers are on separate plants. • Monoecious have staminate and pistillate flowers on the same plant.
Gymnosperms • Gymnosperms are non-flowering plants. • Gymnosperm comes from two Greek words: gymnos which means naked, and sperma which means seed. • The seeds of gymnosperms are exposed.
Divisions of gymnosperms • There are four divisions that are recognized today. • Division Pinophyta. • Division Ginkgophyta. • Division Cycadophyta. • Division Gnetophyta.
Pinophyta • These are coniferous meaning they bear cones. • They have needle like leaves that are stiff, leathery, and resist water loss.
Ginkgophyta • Ginkgo which is derived from Chinese means silver apricot. • It is dioecious, meaning that the male and female parts are produced on separate trees. • Their leaves are fan shaped and broad resembling maidenhair ferns.
Cycadophyta • They are dioecious. • Their leaves are frond like, stiff, leathery, and resist water loss.
Gnetophta • Division Gnetophyta contains four genus: • Ephedra, which can be monoecious or dioecious, depending on species.
Gnetophyta • Gnetium are vine like with broad leaves similar to flowering plants.
Gnetophyta • Welwitschia are dioecious and extraordinary in appearanc.
Works Cited • “Gymnosperm”. Microsoft® Encarta® Online Encyclopedia 2001, http://encarta.msn.com (19 April 2002). • “Angiosperm”. Microsoft® Encarta® Online Encyclopedia 2001, http://encarta.msn.com (19 April 2002). • Stern, Kingsley R., “Flowering Plants”, 398, 399, 417, Introductory Plant Biology, Edition 8, 1997, The McGraw-Hill Companies, Inc.
Photos were taken from • “Flower”, Encarta® Online, http://encarta.msn.com/find/MediaMax.asp (19 April 2002). • Texas Wildflowers Information and Pictures, http://www.lnstar.com/mall/txtrails/wildflowers/flowers.htm (12 April 2002).
California Gardens-Ginkgo biloba-The Maidenhair tree, http://www.californiagardens.com/ • Cycads UW Aberystwyth Botanic Gardens, http://www.aber.acuk/ • Index of /seed plants / gnetophyta, http://www.ucmp.berkeley.edu/seedplants/gnetophyta/
Music was taken from • Enya, “A Day Without Rain”, A Day Without Rain, ©2000 Warner Music, UK, ltd.